Script syntax reference
The IoT Gateway contains a powerful script parser and evaluation engine. The script engine is not ECMAcompliant. Instead, its focus is to provide an efficient and compact script language using mathemathical notation. Following is a brief overview of the syntax different script elements. You can also use the Calculator to experiment with script syntax.
 Primitive data types
 Variable references, Constants and Namespaces
 Canonical extensions
 Operators
 Encapsulation
 Suffixoperators
 Unary prefix operators
 Powers
 Factors
 Binomial Coefficients
 Terms
 Intervals
 Intersections
 Unions
 Shift operators
 Comparison operators
 Membership operators
 AND operators
 OR operators
 Equivalence or implication
 Lambda definition
 Assignment
 Conditional IF
 Lists
 Conditional Statements (DO/WHILE, WHILE/DO, FOR, FOREACH, TRY CATCH FINALLY)
 Sequences
 Functions
 Analytic Functions
 Scalar Functions
 Complex Functions
 String Functions
 Date and Time Functions
 Vector Functions
 Matrix Functions
 Transforms
 Runtime Functions
 Extensions
 Color functions
 Graph functions (Waher.Script.Graphs)
 Palette generation functions (Waher.Script.Fractals)
 Complex Fractal functions (Waher.Script.Fractals)
 Iterated Function System (IFS) Fractal functions (Waher.Script.Fractals)
 Persistencerelated functions
 Statisticsrelated functions
 Contentrelated functions (Waher.Script.Content)
 Markdownrelated functions (Waher.Content.Markdown)
 XSLrelated functions (Waher.Content.Xsl)
 Web Extensions (Waher.Networking.HTTP[.UWP])
 Gateway Extensions (Waher.IoTGateway)
 Custom Parsers
 Interaction with .NET Code Behind classes
 Physical Quantities
Primitive data types
Apart from different ways to create compound data types, the following sections provide a short overview of primitive data types available in script.
Doublevalued numbers
Double valued numbers are written using the following syntax (as a regular expression):
[+]?[09]*([.][09]+)?([eE][+]?[09]+)?
Examples:
1
3.1415927
1.23e3
Complex numbers
Complex valued numbers can be written either by enclosing its real and imaginary parts in a list between parenthesis, as follows:
(Re, Im)
If no variable named i
is defined, it is also possible to use the imaginary unit constant i
, as follows:
Re+Im*i
Both Re
and Im
above are doublevalued numbers.
Boolean values
Boolean values are either written as true
or false
.
Strings
String values are written between single quotes ('
) or double quotes ("
). The backslash character (\
) can be used to escape quote characters, or special control characters in strings, accordig to the following table.
Sequence  Meaning 

\' 
‘ 
\" 
“ 
\\ 
\ 
\n 
Newline character. 
\r 
Carriage return character. 
\t 
Tab character. 
\b 
Backspace character. 
\f 
Formfeed character. 
\a 
Audible bell character. 
\v 
Vertical tab character. 
\xHH 
Inlude a hexadecimally encoded byte. 
Null
The null object reference value is written null
.
Variable references, Constants and Namespaces
Constants are pluggable into the script engine, and new constants can be defined in any library, by creating classes that implement the Waher.Script.Model.IConstant
interface. Constants and root namespaces are referenced in script by simply writing their names, just as variable references are. The order of presedence among them is as follows:
 If a variable is found having the referenced name, it is returned, regardless if there exists a constant or a root namespace with the same name.
 If a constant is found having the referenced name, it is returned if there’s no variable with the same name, regardless if there exists a root namespaces with the same name.
 If a root namespace is found having the referenced name, it is returned if there is no variable or constant with the same name.
The following table lists constants recognized by Waher.Script
. For lists of constants published by other libraries, see the documentation for the corresponding libraries.
Constant  Description 

e 
Euler’s number 
π , pi 
Pi 
ε , eps , epsilon 
Smallest positive double value that is greater than zero. 
∞ , inf , infinity 
Positive infinity. 
i 
Imaginary unit 
C 
Set of complex numbers 
R 
Set of real numbers 
Z 
Set of integer numbers 
∅ , EmptySet 
The empty set 
There are also a set of predefined variables:
Variable  Description 

Now 
Current date and time 
Today 
Current date 
Note: Names are case sensitive. r
and R
point to different objects.
Canonical extensions
The script engine has a feature that automatically generates canonical extensions to operators and functions if the operands and arguments are vectors, sets or matrices, and the original operator or function is defined for scalar operands and arguments. If an operator or function expects vector arguments, and matrices are used, the canonical extension sees a matrix as a vector of row vectors.
Example:
sin([10,20,30]);
[[1,2],[3,4]]+x
The above is evaluated as:
[sin(10),sin(20),sin(30)];
[[1+x,2+x],[3+x,4+x]]
Etc.
Operators
The following operators are supported. They are listed in order of presedence.
Encapsulation
Parenthesis
Normal parenthesis (
and )
can be used to encapsulate operations that have lower order of presedence than surrounding operators, and thus control the execution flow. Example:
a * (b + c)
Vectors
Vectors can be explicitly created by listing their elements between square brackets [
and ]
. Example:
v:=[1,2,3];
Loop construction of vector
Vectors can also be created using any of the DO
WHILE
, WHILE
DO
, FOR
TO
[STEP
][DO
] or FOR EACH
/FOREACH
IN
[DO
] statements between braces. Examples:
v:=[DO x++ WHILE X<10];
v:=[WHILE x<10 : x++];
v:=[FOR x:=1 TO 20 STEP 3 : x];
v:=[FOREACH x IN 1..100.1 : x^2];
v:=[FOR EACH x IN 1..100.1 : x^2];
Note: DO
can be exchanged with :
, or completely omitted, except in the DO
WHILE
case.
Implicit vector notation
Vectors can also be defined implicitly using an implicit vector notation:
[Expression[ in Elements]:Condition1[,Condition2[,...[ConditionN]]]]
This allows you to define vectors based on the contents of other vectors. Example:
X:=1..10;
P:=[x^2:x in X]
Selecting elements
Smaller vectors can be created from larger vectors, by allowing the expression in the implicit vector definition to be a simple variable reference representing an element in the larger vector, and then allowing the conditions in the definition to limit the elements belonging to the shorter vector. Example:
v:=1..100;
[x in v:floor(sqrt(x))^2=x]
Matrices
Matrices can be explicitly created by listing their row vectors between square brackets [
and ]
. Example:
M:=[[1,0,0],[0,1,0],[0,0,1]];
Loop construction of matrix
Matrices can also be created using any of the DO
WHILE
, WHILE
DO
, FOR
TO
[STEP
][DO
] or FOR EACH
/FOREACH
IN
[DO
] statements between braces. Examples:
M:=[DO [x++,x++,x++] WHILE X<10];
M:=[WHILE x<10 : [x++,x++,x++]];
M:=[FOR y:=1 TO 20 : [FOR x:=1 TO 20 : x=y ? 1 : 0]];
M:=[FOREACH x IN 1..100.1 : [x^2,x^3,x^4]];
M:=[FOR EACH x IN 1..100.1 : [x^2,x^3,x^4]];
Note: DO
can be exchanged with :
, or completely omitted, except in the DO
WHILE
case.
Implicit matrix notation
Matrices can also be defined implicitly using implicit vector notation, where the Expression
evaluates to row vectors. Example:
M:=Identity(5);
[Reverse(Row):Row in M]
Sets
Sets are unordered collections of items that can be used in script. There are numerous ways to define sets.
Explicit definition of sets
Sets can be explicitly created by listing their elements between braces {
and }
. Example:
S:={1,2,3};
Loop construction of set
Sets can also be created using any of the DO
WHILE
, WHILE
DO
, FOR
TO
[STEP
][DO
] or FOR EACH
/FOREACH
IN
[DO
] statements between braces. Examples:
S:={DO x++ WHILE X<10};
S:={WHILE x<10 : x++};
S:={FOR x:=1 TO 20 STEP 3 : x};
S:={FOREACH x IN 1..100.1 : x^2};
S:={FOR EACH x IN 1..100.1 : x^2};
Note: DO
can be exchanged with :
, or completely omitted, except in the DO
WHILE
case.
Implicit set notation
Sets can also be defined implicitly using implicit set notation:
{Expression[ in Superset]:Condition1[,Condition2[,...[ConditionN]]]}
This allows you to define infinite sets. Examples:
S:={[a,b]: a>b}
S:={[a,b]: a in Z, b in Z, a>b}
S:={[a,b,c]:a in 1..2, b in 10..13, c in 100..104}
S:={x::x>10}
S:={v[]:count(v)>3}
S:={s{}:count(s)>3}
S:={M[,]:M.Columns>M.Rows}
Note: To differentiate between creating an object ex nihilo, and creating a subset, when no superset is defined, two consequtive colons (:
) can be used. {x::x>10}
creates a set of all items that are comparable to 10
and are greater. {x:x>10}
creates an object ex nihilo with one member x
that will have a boolean value corresponding to the greaterthan comparison of the variable x
with 10
.
Subsets
Subsets can be creted by allowing the expression in the implicit set definition to be a simple variable reference belonging to a superset, and then allowing the conditions in the definition to limit the elements belonging to the subset. Examples:
S:={x in Z:x>10}
S2:={x in S:x<20}
Object Ex nihilo
Objects can be created from nothing, by listing the members between braces {
and }
, separating each one with a comma ,
and each member name from its corresponding value with a colon :
. Example:
{
Member1: Value1,
Member2: Value2,
...
MemberN: ValueN
}
Member names can be both standard variable references, or constant strings. The following example gives the same result as the example above:
{
"Member1": Value1,
"Member2": Value2,
...
"MemberN": ValueN
}
Suffixoperators
Suffixoperators are written after the operand to which they are applied. The following table lists available suffix operators:
Operator  Description  Example 

. 
Member operator  obj.Member 
( List ) 
Function evaluation  f(a,b,c) 
[] 
To vector, if not already  a[] 
[Index] 
Vector index operator  v[i] 
[X,Y] 
Matrix index operator  M[x,y] 
[X,] 
Matrix colum vector operator  M[x,] 
[,Y] 
Matrix row vector operator  M[,y] 
[,] 
To matrix, if not already  a[,] 
{} 
To set, if not already  a{} 
++ 
PostIncrement  a++ 
 
PostDecrement  a 
% 
Percent  10% 
‰ 
Per thousand  20‰ 
%0 
Per thousand  20%0 
‱ 
Per ten thousand  30‱ 
‰0 
Per ten thousand  30‰0 
%00 
Per ten thousand  30%00 
° 
Degrees to radians  sin(100°) 
' 
Default differentiation (prim)  f'(x) 
′ 
Default differentiation (prim)  f′(x) 
" 
Default secondorder differentiation (bis)  f"(x) 
″ 
Default secondorder differentiation (bis)  f″(x) 
‴ 
Default thirdorder differentiation  f‴(x) 
T 
Transposed matrix  M T 
H 
Conjugate Transposed matrix  M H 
† 
Conjugate Transposed matrix  M† 
! 
Faculty  n! 
!! 
SemiFaculty  n!! 
Physical unit  Defines a physical quantity.  10 m/s 
Some suffix operators canbe prefixed by a ?
character, to include a *null checkof the operand. If the operand is
null, the operator is not evaluated, and
nullis returned. The following table lists nullchecked suffix operators:
Operator  Description  Example 

?. 
Member operator  obj?.Member 
?( List ) 
Function evaluation  f?(a,b,c) 
?[] 
To vector, if not already  a?[] 
?[Index] 
Vector index operator  v?[i] 
?[X,Y] 
Matrix index operator  M?[x,y] 
?[X,] 
Matrix colum vector operator  M?[x,] 
?[,Y] 
Matrix row vector operator  M?[,y] 
?[,] 
To matrix, if not already  a?[,] 
?{} 
To set, if not already  a?{} 
Note: Since script is latebound, most operators support dynamic and static bindings, where traditional languages only support static bindings. The following is permitted, for example:
s:="A";
Obj.("Property"+s):=10;
The above is the same as writing
Obj.PropertyA:=10;
Canonical extensions are also possible. Example:
[Obj1,Obj2].Member
Is evaluated as (unless the vector contains a property of that name, such as the Length
property):
[Obj1.Member,Obj2.Member]
Canonical extensions are allowed, on both left side, and right side. Example:
Obj.["member1","member2"]
Is evaluated as:
[Obj1.member1,Obj2.member2]
Note 2: You can combine default differentiation operators to create higher order differentiation operators. Example f''''(x)
represents the fourthorder differentiation operator, and is the same as f""(x)
.
Note 3: For more information about physical units, see the section Physical Quantities below.
Unary prefix operators
Unary prefix operators are written before the operand to which they are applied. The following table lists available unary prefix operators:
Operator  Description  Example 

++ 
PreIncrement  ++a 
 
PreDecrement  a 
+ 
Positive (ignored)  +a 
 
Negation  a 
! 
Logical Not  !a 
NOT 
Logical Not  NOT a 
~ 
Complement  ~a 
Powers
There are two powerlevel operators. Both have the same order of presedence.
Operator  Description  Example 

^ 
Power  a ^ b 
.^ 
Elementwise Power  a .^ b 
There are also a couple of special characters that are understood as power operators:
Operator  Description  Example 

² 
Square  a² 
³ 
Cube  a³ 
Factors
There are several factorlevel operators, apart from the assignment versions. Both have the same order of presedence.
Operator  Description  Example 

* 
Multiplication  a * b 
/ 
Division  a / b 
\ 
LeftDivision, or set difference  a \ b , A\B 
MOD 
Residue (modulus)  a MOD b 
.MOD 
Elementwise Residue  a .MOD b 
.* 
Elementwise Multiplication  a .* b 
./ 
Elementwise Division  a ./ b 
.\ 
Elementwise LeftDivision  a .\ b 
DOT 
Dot product  a DOT b 
CROSS 
Cross product  a CROSS b 
CARTESIAN 
Cartesian product  a CARTESIAN b 
Note: In some languages %
is a residue operator. In this language, the %
operator is a percent operator.
Binomial Coefficients
Binomial coefficients can be calculated using the OVER
operator, as follows:
n OVER k
Terms
There are four termlevel operators, apart from the assignment versions. Both have the same order of presedence.
Operator  Description  Example 

+ 
Addition  a + b 
 
Subtraction  a  b 
.+ 
Elementwise Addition  a .+ b 
. 
Elementwise Subtraction  a . b 
Intervals
Intervals can be created in the following way:
From .. To
By default, the step size is 1. You can specify the step size in the following way:
From .. To  StepSize
Intersections
The intersection of two sets is accomplished as follows:
Set1 INTERSECT Set2.
Set1 INTERSECTION Set2.
The Intersection character ∩
can also be used:
Set1 ∩ Set2
Unions
The union of two sets is accomplished as follows:
Set1 UNION Set2.
The CUP character ∪
can also be used:
Set1 ∪ Set2
Shift operators
There are two shift operators, apart from the assignment versions. Both have the same order of presedence.
Operator  Description  Example 

<< 
Shift left  a << b 
>> 
Shift right  a >> b 
Comparison operators
There are various different comparison operators. All have the same order of presedence.
Operator  Description  Example 

<= 
Lesser than or equal to  a <= b 
< 
Lesser than  a < b 
>= 
Greater than or equal to  a >= b 
> 
Greater than  a > b 
= 
Equal to  a = b 
== 
Equal to  a == b 
=== 
Identical to  a === b 
<> 
Not Equal to  a <> b 
!= 
Not Equal to  a != b 
LIKE 
Matches regular expression  a LIKE regex 
NOT LIKE 
Does not match regular expression  a NOT LIKE regex 
NOTLIKE 
Does not match regular expression  a NOTLIKE regex 
UNLIKE 
Does not match regular expression  a UNLIKE regex 
.= 
Equal to (elementwise)  a .= b 
.== 
Equal to (elementwise)  a .== b 
.=== 
Identical to (elementwise)  a .=== b 
.<> 
Not Equal to (elementwise)  a .<> b 
.!= 
Not Equal to (elementwise)  a .!= b 
Note: Elementwise variant of operators only exist for equality or nonequality operators, since these are also defined when comparing encapsulating objects such as sets, vectors, arrays, matrices, etc.
Note 2: If regular expressions contain named groups, variables with the corresponding names will be set to the contents of the corresponding groups if the regular expression matches the string.
Membership operators
There are various different membership operators. All have the same order of presedence.
Operator  Description  Example 

AS 
The AS operator makes sure the left operand is of the same type as the right operand. The result is null if they are not, or the same value as the left operand if they are. 
Value as Type 
IS 
The IS operator checks if the left operand is of the same type as the right operand. 
Value is Type 
IN 
The IN operator checks if the left operand is a member of the right operand. 
Value in Set 
NOT IN 
The NOT IN or NOTIN operator checks if the left operand is not a member of the right operand. 
Value not in Set 
NOTIN 
The NOT IN or NOTIN operator checks if the left operand is not a member of the right operand. 
Value notin Set 
AND operators
There are various different AND operators. All have the same order of presedence.
Operator  Description  Example 

& 
To specify an explicit logical AND operator, use the & operator. 
a & b 
&& 
To specify an explicit binary AND operator, use the && operator. 
a && b 
AND 
The AND operator (case insensitive) works differently depending on the values being operated on. If they are boolean values, the operator works as a logical operator. If they are integers, the operator works as a binary operator. 
a and b 
NAND 
The NAND operator (case insensitive), or the notand operator, works differently depending on the values being operated on. If they are boolean values, the operator works as a logical operator. If they are integers, the operator works as a binary operator. 
a nand b 
OR operators
There are various different OR operators. All have the same order of presedence.
Operator  Description  Example 

 
To specify an explicit logical OR operator, use the  operator. 
a  b 
 
To specify an explicit binary OR operator, use the  operator. 
a  b 
OR 
The OR operator (case insensitive) works differently depending on the values being operated on. If they are boolean values, the operator works as a logical operator. If they are integers, the operator works as a binary operator. 
a or b 
NOR 
The NOR operator (case insensitive), or the notor operator, works differently depending on the values being operated on. If they are boolean values, the operator works as a logical operator. If they are integers, the operator works as a binary operator. 
a nor b 
XOR 
The XOR operator (case insensitive) works differently depending on the values being operated on. If they are boolean values, the operator works as a logical operator. If they are integers, the operator works as a binary operator. 
a xor b 
XNOR 
The XNOR operator (case insensitive), or the notxor operator, works differently depending on the values being operated on. If they are boolean values, the operator works as a logical operator. If they are integers, the operator works as a binary operator. 
a xnor b 
Note: The XNOR operator has the same truth table as the equivalence operator <=>
, but the order of presedence is different.
Equivalence or implication
Equivalence or implication operators have the same order of presedence.
Equivalence
The equivalence operator is a boolean operator that checks if the both sides are equivalent (or equal, as boolean values). Example:
a <=> b
Truth table:
<=> 
⊤  ⊥ 

⊤  ⊤  ⊥ 
⊥  ⊥  ⊤ 
Implication
The implication operator is a boolean operator that checks if the left side implies the right side (as boolean values). Example:
a => b
Truth table:
=> 
⊤  ⊥ 

⊤  ⊤  ⊥ 
⊥  ⊤  ⊤ 
Lambda definition
A lambda definition creates an implicit unnamed function. A lambda definition is created by using the >
operator. If multiple parameters are used, they must be enclosed between parenthesis. Examples:
x>x^2;
(x,y)>sin(x)*exp(1/y^2);
Note: Implicit lambda definitions are created if referring to a function by using only its name. If writing only abs
, a lambda definition x>abs(x)
will be returned. This makes it possible to create functions taking lambda expressions as parameters, implementing algorithms, and call them using simple references to the existing function library.
Lambda definitions and canonical extensions
When defining lambda functions you can provide information on how arguments are to be treated, and thus also implicitly automatically define canonical extensions for the expression. Each argument x
can be defined to belong to one of five categories:
Argument  Category  Example 

x 
Normal argument. When the expression is called, arguments are passed as they are given.  x>... 
[x] 
Scalar argument. When the expression is called with nonscalar arguments such as vectors and matrices, the function is canonically extended by calling the function repeatedly for each scalar element, and returning a structure similar to the structure of the argument.  [x]>... 
x[] 
Vector argument. When the expression is called with scalar arguments, they are converted to onedimensional vectors. If matrix arguments are used, the function is canonically extended by calling the function repeatedly for each row vector of the matrix, and returning a structure similar to the structure of the argument. If a set is passed, the extension loops through the elements of the set canonically.  v[]>... 
x{} 
Set argument. When the expression is called with scalar arguments, they are converted to onedimensional sets. If matrix arguments are used, the function is canonically extended by calling the function repeatedly for each row vector of the matrix, and returning a structure similar to the structure of the argument. If a vector is passed, it is converted to a set.  v{}>... 
x[,] 
Matrix argument. When the expression is called with scalar or vector arguments, they are converted to 1x1 matrices or matrices consisting of only one row. If a set is passed, the extension loops through the elements of the set canonically.  M[,]>... 
Assignment
A variable assignment is defined using the :=
operator. Example:
Variable := Value
If the left side is not a variable reference, a pattern matching algorithm is employed that tries to assign all implicitly available variable references by comparing both sides.
Examples:
[x,y]:=f(a,b,c)
v[]:=f(a,b,c)
In the first example, the function f
, which takes three parameters, is supposed to return a vector of two elements. If it does, the variables x
and y
are assigned the elements of this return vector. In the second example, the v
is supposed to be a assigned a vector. If the result of the function call is not a vector, it is converted to a vector before being assigned to v
.
There’s also a set of aritmethic operators that act directly on a variable value. These are also categorized as assignment operators, and have the same order of presedence. These operators are:
Operator  Meaning  Example 

+= 
Add to variable  Variable += Value 
= 
Subtract from variable  Variable = Value 
*= 
Multiply to variable  Variable *= Value 
/= 
Divide from variable  Variable /= Value 
^= 
Power variable  Variable ^= Value 
&= 
Binary AND with variable  Variable &= Value 
&&= 
Logical AND with variable  Variable &&= Value 
= 
Binary OR with variable  Variable = Value 
= 
Logical OR with variable  Variable = Value 
<<= 
Shift variable left  Variable <<= Value 
>>= 
Shift variable right  Variable >>= Value 
Note: ^=
is not a logical XOR with self operator but a power of self operator.
You can also combine operators to perform partial assignments, as follows:
Operator  Meaning  Example 

… . … := 
Membership assignment  Obj.Member := Value 
… [ … ]:= 
Vector index assignment  Vector[Index] := Value 
… [ … , … ]:= 
Matrix index assignment  M[x,y] := Value 
… [ … ,]:= 
Matrix column assignment  M[x] := Value 
… [, … ]:= 
Matrix row assignment  M[,y] := Value 
… ( … ):= 
Function definition  f(x,y,z) := x*y*z 
Function definitions and canonical extensions
When defining functions you can provide information on how arguments are to be treated, and thus also implicitly automatically define canonical extensions for the function. Each argument x
can be defined to belong to one of five categories:
Argument  Category  Example 

x 
Normal argument. When the expression is called, arguments are passed as they are given.  f(x):=... 
[x] 
Scalar argument. When the expression is called with nonscalar arguments such as vectors and matrices, the function is canonically extended by calling the function repeatedly for each scalar element, and returning a structure similar to the structure of the argument.  f([x]):=... 
x[] 
Vector argument. When the expression is called with scalar arguments, they are converted to onedimensional vectors. If matrix arguments are used, the function is canonically extended by calling the function repeatedly for each row vector of the matrix, and returning a structure similar to the structure of the argument. If a set is passed, the extension loops through the elements of the set canonically.  f(v[]):=... 
x{} 
Set argument. When the expression is called with scalar arguments, they are converted to onedimensional sets. If matrix arguments are used, the function is canonically extended by calling the function repeatedly for each row vector of the matrix, and returning a structure similar to the structure of the argument. If a vector is passed, it is converted to a set.  f(v{}):=... 
x[,] 
Matrix argument. When the expression is called with scalar or vector arguments, they are converted to 1x1 matrices or matrices consisting of only one row. If a set is passed, the extension loops through the elements of the set canonically.  f(M[,]):=... 
Conditional IF
Conditional IF
statements can be written in various ways. Either using the IF
and THEN
keywords, followed by the optional ELSE
keyword, or by using the ?
operator, followed by the optional :
operator. There is also a quick nullcheck statement.
Examples:
IF Condition THEN IfTrueStatement
IF Condition THEN IfTrueStatement ELSE IfFalseStatement
Condition ? IfTrueStatement
Condition ? IfTrueStatement : IfFalseStatement
Statement ?? IfNullStatement
Note: IF
, THEN
and ELSE
are case insensitive. They are written here using upper case for clarity.
Note 2: If no ELSE
or :
is present, the statement is evaluated to null.
Lists
Lists of statements are created by writing a list of statements or arguments, each separated by a comma ,
character. Example:
Statement1, Statement2, Statement3, ...
Whitespace is ignored. This includes newline characters. So Statements can be written on separate rows. Example:
Statement1,
Statement2,
Statement3,
...
Lists are used in different constructs, such as function definitions and evaluations, lambda definitions, or when working with sets, vectors or matrices, for example.
It is permissible to ignore arguments in a list. Such arguments will implicitly receive the value null. Example:
Arg1, Arg2,, Arg4
Here, there third argument will have value null.
Conditional Statements (DO/WHILE, WHILE/DO, FOR, FOREACH, TRY CATCH FINALLY)
There are multiple ways to execute conditional loops. These statements have the same order of presedence:
Operator  Meaning  Example 

DO … WHILE … 
Performs an action until a condition becomes true.  DO Statement WHILE Condition 
WHILE … _{DO}… 
While a condition is true, performs an action.  WHILE Condition DO Statement 
FOREACH … IN … _{DO}… 
Iterates a variable through an enumerable set of values and performs an action on each iterated value.  FOREACH Variable in Collection DO Statement 
FOR EACH … IN … _{DO}… 
Iterates a variable through an enumerable set of values and performs an action on each iterated value.  FOR EACH Variable in Collection DO Statement 
FOR … := … TO … STEP … … 
Iterates a variable through a sequence of numerical values and performs an action on each iterated value.  FOR Variable:=From TO Stop STEP StepSize DO Statement 
TRY … CATCH … FINALLY … 
Executes a statement. If an exception occurs, it is caught and an exception statement is executed. Afterwards, a finalization statement is executed. The exception object will be available in the CATCH statement, under the name of Exception . 
TRY Statement CATCH Exception FINALLY Done 
TRY … CATCH … 
Executes a statement. If an exception occurs, it is caught and an exception statement is executed. The exception object will be available in the CATCH statement, under the name of Exception . 
TRY Statement CATCH Exception 
TRY … FINALLY … 
Executes a statement. Afterwards, a finalization statement is executed regardless if an exception has been thrown or not. Any exceptions are automatically propagated.  FOR Statement FINALLY Done 
]] …[[ 
Implicit print statement. This operation prints the contents between the ]] and [[ to the current console output. Any expressions embedded between (( and )) will be evaluated and the result displayed. 
a:=10;]]Value of a: ((a)).[[; 
Note: The DO
keyword can be replaced by a :
.
Note 2: The use of the STEP
keyword together with the step size is optional. If omitted, a default step size of 1
or 1
will be used, depending if the loop is ascending or descending.
Sequences
Sequences of statements are created by writing a list of statements, each separated by a semicolon ;
character. Example:
Statement1; Statement2; Statement3; ...
Whitespace is ignored. This includes newline characters. So Statements can be written on separate rows. Example:
Statement1;
Statement2;
Statement3;
...
Functions
Functions are extensible and can be defined in any module in the solution. A complete list of functions available in a solution therefore depends on all libraries included in the project. Functions listed here only include functions defined in this library.
Note: Function names are case insensitive.
Analytic Functions
The following subsections list available analytic or partially analytic functions, partitioned into groups.
Exponential and power functions
The following table lists available exponential and power functions:
Function  Description  Example 

Exp(z) 
e raised to the power of z . 
Exp(10) 
Ln(z) 
Natural logarithm of z . 
Ln(e) 
Lg(z) 
Base10 logarithm of z . 
Lg(10) 
Log10(z) 
Alias for lg . 
Lg(10) 
Log2(z) 
Base2 logarithm of z . 
Log2(2) 
Sqrt(z) 
Square root of z . 
Sqrt(2) 
Trigonometric functions
The following table lists available trigonometric functions:
Function  Description  Example 

Cos(z) 
Cosine, z in radians. 
Cos(100°) 
Cot(z) 
Cotangent, z in radians. 
Cot(100°) 
Csc(z) 
Cosecant, z in radians. 
Csc(100°) 
Sec(z) 
Secant, z in radians. 
Sec(100°) 
Sin(z) 
Sine, z in radians. 
Sin(100°) 
Tan(z) 
Tangent, z in radians. 
Tan(100°) 
ACos(z) 
Alias for ArcCos(z) . 
ACos(Cos(100°)) 
ACot(z) 
Alias for ArcCot(z) . 
ACot(Cot(100°)) 
ACsc(z) 
Alias for ArcCsc(z) . 
ACsc(Csc(100°)) 
ASec(z) 
Alias for ArcSec(z) . 
ASec(Sec(100°)) 
ASin(z) 
Alias for ArcSin(z) . 
ASin(Sin(100°)) 
ATan(z) 
Alias for ArcTan(z) . 
ATan(Tan(100°)) 
ATan(x,y) 
Alias for ArcTan(x,y) . 
ATan(3,4) 
ArcCos(z)) 
Inverse Cosine.  ArcCos(Cos(100°)) 
ArcCot(z)) 
Inverse Cotangent.  ArcCot(Cot(100°)) 
ArcCsc(z)) 
Inverse Cosecant.  ArcCsc(Csc(100°)) 
ArcSec(z)) 
Inverse Secant.  ArcSec(Sec(100°)) 
ArcSin(z) 
Inverse Sine.  ArcSin(Sin(100°)) 
ArcTan(z)) 
Inverse Tangent.  ArcTan(Tan(100°)) 
ArcTan(x,y)) 
Returns the angle whose tangent is the quotient of two specified numbers.  ArcTan(3,4) 
Hyperbolic functions
A corresponding set of hyperbolic functions also exists:
Function  Description  Example 

CosH(z) 
Hyperbolic Cosine, z in radians. 
CosH(100°) 
CotH(z) 
Hyperbolic Cotangent, z in radians. 
CotH(100°) 
CscH(z) 
Hyperbolic Cosecant, z in radians. 
CscH(100°) 
SecH(z) 
Hyperbolic Secant, z in radians. 
SecH(100°) 
SinH(z) 
Hyperbolic Sine, z in radians. 
SinH(100°) 
TanH(z) 
Hyperbolic Tangent, z in radians. 
TanH(100°) 
ACosH(z) 
Alias for ArcCosH(z) . 
ACosH(CosH(100°)) 
ACotH(z) 
Alias for ArcCotH(z) . 
ACotH(CotH(100°)) 
ACscH(z) 
Alias for ArcCscH(z) . 
ACscH(CscH(100°)) 
ASecH(z) 
Alias for ArcSecH(z) . 
ASecH(SecH(100°)) 
ASinH(z) 
Alias for ArcSinH(z) . 
ASinH(SinH(100°)) 
ATanH(z) 
Alias for ArcTanH(z) . 
ATanH(TanH(100°)) 
ArcCosH(z)) 
Inverse Hyperbolic Cosine.  ArcCosH(CosH(100°)) 
ArcCotH(z)) 
Inverse Hyperbolic Cotangent.  ArcCotH(CotH(100°)) 
ArcCscH(z)) 
Inverse Hyperbolic Cosecant.  ArcCscH(CscH(100°)) 
ArcSecH(z)) 
Inverse Hyperbolic Secant.  ArcSecH(SecH(100°)) 
ArcSinH(z) 
Inverse Hyperbolic Sine.  ArcSinH(SinH(100°)) 
ArcTanH(z)) 
Inverse Hyperbolic Tangent.  ArcTanH(TanH(100°)) 
Scalar Functions
The following table lists available scalar functions:
Function  Description  Example 

Abs(z) 
Absolute value (or magnitude of) z 
Abs(1) 
Bool(x) 
Alias for Boolean . 
Bool('true') 
Boolean(x) 
Converts x to a boolean value. 
Boolean('true') 
Ceiling(z) 
Round z up to closest integer. 
Ceiling(pi) 
Ceil(z) 
Alias for Ceiling(z) . 
Ceil(1) 
Floor(z) 
Round z down to closest integer. 
Floor(pi) 
Max(x,y) 
Largest of x and y . 
Max(10,a) 
Min(x,y) 
Smallest of x and y . 
Min(10,a) 
Num(x) 
Alias for Number(x) . 
Num('100') 
Number(x) 
Converts x to a number. 
Number('100') 
Round(z) 
Round z up or down to closest integer. 
Round(pi) 
Sign(z) 
Sign of z (1/0/1 + i/0/+i). 
Sign(pi) 
Str(x) 
Alias for String(x) . 
Str(100) 
String(x) 
Converts x to a string. 
String(100)

Complex Functions
The following table lists available scalar functions:
Function  Description  Example 

Arg(z) 
Argument (or phase) of z . 
Arg(2+i) 
Conj(z) 
Alias for Conjugate(z) . 
Conj(2+i) 
Conjugate(z) 
Conjugate of z . 
Conjugate(2+i) 
Im(z) 
Imaginary part of z . 
Im(2+i) 
Polar(n,φ) 
Complex number given in polar coordinates n and φ . 
Polar(1,pi/2) 
Re(z) 
Real part of z . 
Re(2+i) 
String Functions
The following table lists available stringrelated functions:
Function  Description  Example 

Empty(s) 
Alias for IsEmpty(s) . 
Empty(s) 
Eval(s) 
Alias for Evaluate(s) . 
Evaluate("a+b") 
Evaluate(s) 
Parses the string and evaluates it.  Evaluate("a+b") 
IsEmpty(s) 
Returns a boolean value showing if the string s is empty or not. 
IsEmpty(s) 
Left(s,N) 
Returns a string with the leftmost N characters. If the string s is shorter, the entire string is returned. 
Left(s,3) 
Len(s) 
Alias for Length(s) . 
Len(s) 
Length(s) 
Returns the length of the string.  Length(s) 
Mid(s,Pos,Len) 
Returns a substring of s , starting a character Pos and continuing Len characters. The Pos index is zerobased. If the requested substring goes beyond the scope of s , the substring gets truncated accordingly. 
Mid(s,5,2) 
Parse(s) 
Parses the string as an expression, and returns the parsed expression.  Parse("a+b") 
Right(s,N) 
Returns a string with the rightmost N characters. If the string s is shorter, the entire string is returned. 
Right(s,3) 
Date and Time Functions
Function  Description  Example 

DateTime(Year,Month,Day) 
Creates a Date value.  DateTime(2016,03,05) 
DateTime(Year,Month,Day,Hour,Minute,Second) 
Creates a Date and Time value.  DateTime(2016,03,05,19,17,23) 
DateTime(Year,Month,Day,Hour,Minute,Second,MSecond) 
Creates a Date and Time value.  DateTime(2016,03,05,19,17,23,123) 
Vector Functions
The following functions operate on vectors:
Function  Description  Example 

And(v) 
Logical or binary AND of all elements in vector  And([1,2,3,4,5]) , And([true,false,true]) 
Avg(v) 
Alias for Average(v) 
Avg([1,2,3,4,5]) 
Average(v) 
Average of elements in the vector v . 
Average([1,2,3,4,5]) 
Count(v) 
Number of elements in the vector v . 
Count([1,2,3,4,5]) 
Count(v,x) 
Number of elements in the vector v that are equal to x . 
Count([1,2,3,2,1],2) 
Join(v1,v2[,v3[,v4[,v5[,v6[,v7[,v8[,v9]]]]]]]) 
Joins a sequence of vectors, into a larger vector.  Join(v1,v2) 
Left(v,N) 
Returns a vector with the leftmost N elements. If the vector v is shorter, the entire vector is returned. 
Left(v,3) 
Max(v) 
The largest element in the vector v . 
Max([1,2,3,4,5]) 
Median(v) 
The median element in the vector v . 
Median([1,2,3,4,5]) 
Mid(v,Pos,Len) 
Returns a vector containing elements from v , starting a element Pos and continuing Len elements. The Pos index is zerobased. If the requested vector goes beyond the scope of v , the resulting vector gets truncated accordingly. 
Mid(v,5,2) 
Min(v) 
The smallest element in the vector v . 
Min([1,2,3,4,5]) 
Nand(v) 
Logical or binary NAND of all elements in vector  Nand([1,2,3,4,5]) , Nand([true,false,true]) 
Nor(v) 
Logical or binary NOR of all elements in vector  Nor([1,2,3,4,5]) , Nor([true,false,true]) 
Ones(N) 
Creates an Ndimensional vector with all elements set to 1.  Ones(5) 
Or(v) 
Logical or binary OR of all elements in vector  Or([1,2,3,4,5]) , Or([true,false,true]) 
Prod(v) 
Alias for Product(v) 
Prod([1,2,3,4,5]) 
Product(v) 
Product of elements in the vector v . 
Product([1,2,3,4,5]) 
Reverse(v) 
Returns a vector with the elements of the original vector v in reverse order. 
Reverse([1,2,3,4,5]) 
Right(v,N) 
Returns a vector with the rightmost N elements. If the vector v is shorter, the entire vector is returned. 
Right(v,3) 
Sort(v[,x1[,x2][,x3][,x4][,x5][,x6][,x7][,x8][,x9]]) 
Sorts a vector v . x1 x9 are optional, and can be index values, field names or lambda expressions, and determine how to sort the vector v . Negative index numbers, or property of field names beginning with a hyphen  are sorted in decending order. Index numbers are onebased, as opposed to normal index values that are zerobased. 
Sort(v,"Field") 
StdDev(v) 
Alias for StandardDeviation(v) 
StdDev([1,2,3,4,5]) 
StandardDeviation(v) 
Standard deviation of elements in the vector v . 
StandardDeviation([1,2,3,4,5]) 
Sum(v) 
Sum of elements in the vector v . 
Sum([1,2,3,4,5]) 
Var(v) 
Alias for Variance(v) 
Var([1,2,3,4,5]) 
Variance(v) 
Variance of elements in the vector v . 
Variance([1,2,3,4,5]) 
Xnor(v) 
Logical or binary XNOR of all elements in vector  Xnor([1,2,3,4,5]) , Xnor([true,false,true]) 
Xor(v) 
Logical or binary XOR of all elements in vector  Xor([1,2,3,4,5]) , Xor([true,false,true]) 
Zeroes(N) 
Creates an Ndimensional vector with all elements set to 0.  Zeroes(5) 
Matrix Functions
The following functions operate on matrices:
Function  Description  Example 

Identity(N) 
Creates an NxN identity matrix.  Identity(10) 
Inv(M) 
Alias for Invert(M) . 
Inv([[1,1],[0,1]]) 
Inverse(M) 
Alias for Invert(M) . 
Inverse([[1,1],[0,1]]) 
Invert(M) 
Inverts M . Works on any invertable element. 
Invert([[1,1],[0,1]]) 
Transforms
The following functions generate transformation matrices:
Function  Description  Example 

Rotate2D(rad) 
Generates a rotation matrix in twodimensional space. rad is given in radians. The ° operator can be used to convert degrees to radians. 
Rotate2D(45°) 
Rotate2DH(rad) 
Generates a rotation matrix in twodimensional space using homogeneous coordinates. rad is given in radians. The ° operator can be used to convert degrees to radians. 
Rotate2DH(45°) 
Scale2D(sx,sy) 
Generates a scaling matrix in twodimensional space.  Scale2D(0.5,2) 
Scale2DH(sx,sy) 
Generates a scaling matrix in twodimensional space using homogeneous coordinates.  Scale2DH(0.5,2) 
Translate2DH(dx,dy) 
Generates a translation matrix in twodimensional space using homogeneous coordinates.  Translate2DH(10,20) 
Runtime Functions
The following functions are useful to control the runtime execution of the script:
Function  Description  Example 

Create(Type[,ArgList]) 
Creates an object instance of type Type . ArgList contains an optional list of arguments. If Type is a generic type, the generic type arguments precede any constructor arguments. 
Create(System.String,'',80) 
Delete(x) 
Alias for Destroy(x) . 
Delete(x) 
Destroy(x) 
Destroys the value x . If the function references a variable, the variable is also removed. 
Destroy(x) 
Error(Msg) 
Throws an error/exception.  Error('Something went wrong.') 
Exception(Msg) 
Alias for Error(Msg) . 
Exception('Something went wrong.') 
Exists(f) 
Checks if the expression defined by f is valid or not. 
Exists(x) 
Fields(x) 
If x is a type, Fields(x) returns a vector of field names. If x is not a type, Fields(x) returns a matrix containing field names and values. 
Properties(Ans) 
Methods(x) 
If x is a type, Methods(x) returns a vector of methods represented as strings. If x is not a type, Methods(x) returns a matrix containing method names and lambda functions that can be used to execute the corresponding methods. 
Methods(Ans) 
Print(Msg) 
Prints a message to the current console output (which is defined in the variables collection).  Print(x) 
PrintLine(Msg) 
Prints a message followed by a newline to the current console output.  PrintLine(x) 
PrintLn(Msg) 
Alias for PrintLine(Msg) . 
PrintLine(x) 
Properties(x) 
If x is a type, Properties(x) returns a vector of property names. If x is not a type, Properties(x) returns a matrix containing property names and values. 
Properties(Ans) 
Remove(Var) 
Removes the varable Var without destroying its contents. 
Remove(x) 
Return(x) 
Returns from the current function scope with the value x . 
return(Result) 
Extensions
The script engine can be extended by modules that are run in the environment. The following subssections list such funcion extensions made available in different modules available by default on the gateway. This list does not include funcion extensions made available by applications that are not part of the IoT Gateway.
Color functions
The following functions are available in the Waher.Script.Graphs
library.
Function  Description  Example 

Alpha(Color,Alpha) 
Sets the Alpha channel of a color.  Alpha("Red",128) 
Blend(c1,c2,p) 
Blends colors c1 and c2 together using a blending factor 0≤p ≤1. Any or both of c1 and c2 can be an image. 
Blend("Red","Green",0.5) 
Color(string) 
Parses a string and returns the corresponding color. The color can either be a known color name, or in any of the formats RRGGBB , RRGGBBAA , #RRGGBB , #RRGGBBAA . 
Color("Red") 
GrayScale(Color) 
Converts a color to its corresponding Grayscale value.  GrayScale(cl) 
HSL(H,S,L) 
Creates a color from its HSL representation.  HSL(100,0.5,0.7) 
HSLA(H,S,L,A) 
Creates a color from its HSLA representation.  HSLA(100,0.5,0.7,64) 
HSV(H,S,V) 
Creates a color from its HSV representation.  HSV(100,0.5,0.7) 
HSVA(H,S,V,A) 
Creates a color from its HSVA representation.  HSVA(100,0.5,0.7,64) 
RGB(R,G,B) 
Creates a color from its RGB representation.  RGB(100,150,200) 
RGBA(R,G,B,A) 
Creates a color from its RGBA representation.  RGBA(100,150,200,64) 
Graph functions (Waher.Script.Graphs)
The following functions are available in the Waher.Script.Graphs
library. In an interactive script environment, clicking on the resulting graphs will return a vector corresponding to the point under the mouse.
Function  Description  Example 

HorizontalBars(Labels,Values[,Color]) 
Plots a twodimensional stacked horizontal bar chart.  Example 
Plot2DArea(X,Y[,Color]) 
Plots a stacked area chart.  Example 
Plot2DCurve(X,Y[,Color[,PenSize]]) 
Plots a smooth twodimensional curve.  Example 
Plot2DCurveArea(X,Y[,Color]) 
Plots a stacked spline area chart.  Example 
Plot2DLayeredArea(X,Y[,Color]) 
Plots a layered area chart.  Example 
Plot2DLayeredCurveArea(X,Y[,Color]) 
Plots a layered spline area chart.  Example 
Plot2DLayeredLineArea(X,Y[,Color]) 
Alias for Plot2DLayeredArea . 
Example 
Plot2DLayeredSplineArea(X,Y[,Color]) 
Alias for Plot2DLayeredCurveArea . 
Example 
Plot2DLine(X,Y[,Color[,PenSize]]) 
Alias for Plot2DCurve . 
Example 
Plot2DLineArea(X,Y[,Color]) 
Alias for Plot2DArea . 
Example 
Plot2DSpline(X,Y[,Color[,PenSize]]) 
Plots a smooth twodimensional curve.  Example 
Plot2DSplineArea(X,Y[,Color]) 
Alias for Plot2DCurveArea . 
Example 
Polygon2D(X,Y[,Color]) 
Plots a filled polygon.  Example 
Scatter2D(X,Y[,Color[,BulletSize]]) 
Plots a twodimensional scatter diagram.  Example 
VerticalBars(Labels,Values[,Color]) 
Plots a twodimensional stacked vertical bar chart.  Example 
The following table lists variables that control graph output:
Varaible  Description  Current value 

GraphWidth  Width of graph, in pixels.  
GraphHeight  Height of graph, in pixels. 
The following table lists properties on 2Dgraph object that can be used to control how the graph is rendered:
Property  Type  Description  Default value 

ShowXAxis  Boolean  If the xaxis is to be displayed  true 
ShowYAxis  Boolean  If the yaxis is to be displayed  true 
ShowGrid  Boolean  If the grid is to be displayed  true 
You can combine graphs using the +
operator, as long as graph axes are compatible:
x:=10..10;
y:=sin(x);
y2:=2*sin(x);
plot2dcurvearea(x,y,rgba(255,0,0,64))+
plot2dcurvearea(x,y2,rgba(0,0,255,64))+
plot2dcurve(x,y)+
plot2dcurve(x,y2,"Blue")+
scatter2d(x,y,"Red",5)+
scatter2d(x,y2,"Blue",5)
Use the GraphWidth
and GraphHeight
variables to control graph output size. The following example shows how to construct a Sparkline graph:
x:=0..100;
y0:=0;
y:=[foreach i in x do y0:=y0+Uniform(1,1)];
GraphWidth:=200;
GraphHeight:=25;
Sparkline:=plot2dline(x,y,"Black",1)+scatter2d(100,y[y.Length1],"Red",2);
Sparkline.ShowXAxis:=false;
Sparkline.ShowYAxis:=false;
Sparkline.ShowGrid:=false;
Sparkline;
If you use layered graphs that are painted ontop of underlying graphs, you can use the alpha channel to add transparency:
x:=10..10;
y:=sin(x);
y2:=2*sin(x/2);
plot2dlayeredcurvearea(x,y,rgba(255,0,0,64))+
plot2dlayeredcurvearea(x,y2,rgba(0,0,255,64))+
plot2dcurve(x,y)+
plot2dcurve(x,y2,"Blue")+
scatter2d(x,y,"Red",5)+
scatter2d(x,y2,"Blue",5)
You can set the properties Title
, LabelX
and LabelY
to descriptive strings, to provide information to the reader:
GraphWidth:=800;
GraphHeight:=400;
f:=x>sin(5*x)*exp((x^2/10));
x:=10..100.1;
G:=plot2dcurve(x,f(x),"Blue")+plot2dcurve(x,f'(6)*(x6)+f(6))+plot2dcurve(x,f'(6)*(x+6)+f(6))+scatter2d([6,6],[f(6),f(6)],"Red");
G.Title:="Tangent at x=6 and x=6";
G.LabelX:="x";
G.LabelY:="y=sin(5x)exp((x^2/10))";
G
Palette generation functions (Waher.Script.Fractals)
The following functions can be used to randomly create color palettes. The functions are available in the Waher.Script.Fractals
library. In an interactive script environment, clicking on the resulting graphs will zoom into the fractal, unless otherwise stated.
Function  Description  Example 

LinearColors(Colors[,N[,BandSize]]) 
Creates a cyclic palette of N colors (default=1024) from an array of Colors , by linear interpolation over bands of BandSize intermediate colors (default=16). 
TestColorModel(LinearColors(["Red","Green","Blue"],1024,64)) 
RandomLinearAnalogousHSL([N[,BandSize[,Seed]]]) 
Creates a palette of N colors (default=1024) consisting of bands of BandSize intermediate colors (default=16) interpolating random colors analogous in HSL space. The random number generator can be initialized by a Seed , if provided, or use a random one. 
TestColorModel(RandomLinearAnalogousHSL(1024,64)) 
RandomLinearAnalogousHSV([N[,BandSize[,Seed]]]) 
Creates a palette of N colors (default=1024) consisting of bands of BandSize intermediate colors (default=16) interpolating random colors analogous in HSV space. The random number generator can be initialized by a Seed , if provided, or use a random one. 
TestColorModel(RandomLinearAnalogousHSV(1024,64)) 
RandomLinearComplementaryHSL([N[,BandSize[,Seed]]]) 
Creates a palette of N colors (default=1024) consisting of bands of BandSize intermediate colors (default=16) interpolating random colors complementary in HSL space. The random number generator can be initialized by a Seed , if provided, or use a random one. 
TestColorModel(RandomLinearComplementaryHSL(1024,64)) 
RandomLinearComplementaryHSV([N[,BandSize[,Seed]]]) 
Creates a palette of N colors (default=1024) consisting of bands of BandSize intermediate colors (default=16) interpolating random colors complementary in HSV space. The random number generator can be initialized by a Seed , if provided, or use a random one. 
TestColorModel(RandomLinearComplementaryHSV(1024,64)) 
RandomLinearRGB([N[,BandSize[,Seed]]]) 
Creates a palette of N colors (default=1024) consisting of bands of BandSize intermediate colors (default=16) interpolating random colors in RGB space. The random number generator can be initialized by a Seed , if provided, or use a random one. 
TestColorModel(RandomLinearRGB(1024,64)) 
RandomSingleHue([N[,BandSize[,Seed]]]) 
Creates a palette of N colors (default=1024) consisting of bands of BandSize intermediate colors (default=16) interpolating random colors using a single Hue. The random number generator can be initialized by a Seed , if provided, or use a random one. 
TestColorModel(RandomSingleHue(1024,64)) 
Complex Fractal functions (Waher.Script.Fractals)
The following functions can be used to create fractal images based on iterations in the complex plane. The functions are available in the Waher.Script.Fractals
library. They can be used as a means to create backgound images for themes, etc.
Function  Description  Example 

HalleyBuilderFractal(z,dr,R[,Coefficients[,Palette[,DimX[,DimY]]]]) 
Calculates a Halley Fractal Image. When clicked (in a GUI that supports user interaction with resulting images), adds a root to the underying polynomial, instead of zooming in.  HalleyBuilderFractal((0,0),3,) 
HalleyFractal(z,dr,R[,Coefficients[,Palette[,DimX[,DimY]]]]) HalleyFractal(z,dr,R[,Lambda[,Palette[,DimX[,DimY]]]]) 
Calculates a Halley Fractal Image.  HalleyFractal((0,0),3,,[1,0,0,0,0,0,1]) 
HalleySmoothFractal(z,dr,R[,Coefficients[,Palette[,DimX[,DimY]]]]) HalleySmoothFractal(z,dr,R[,Lambda[,Palette[,DimX[,DimY]]]]) 
As HalleyFractal , except the image is smoothed out using the Heat Equation. Pixels where colors change are used as fixed boundary conditions. 
HalleySmoothFractal((0,0),3,,[1,0,0,0,0,0,1]) 
HalleyTopographyFractal(z,dr,R[,Coefficients[,Palette[,DimX[,DimY]]]]) HalleyTopographyFractal(z,dr,R[,Lambda[,Palette[,DimX[,DimY]]]]) 
As HalleyFractal , except only pixels where the color changes are returned, creating a topographical map of the image. 
HalleyTopographyFractal((0,0),3,,Uniform(0,5,8),,640,480) 
JuliaFractal(z,c,dr[,Palette[,DimX[,DimY]]]) JuliaFractal(z,Lambda,dr[,Palette[,DimX[,DimY]]]) 
Calculates a Julia Fractal Image.  JuliaFractal((0,0),(0.785028076171875,0.1465322265625),3,RandomLinearAnalogousHSL(1024,16,2056656298),640,480) JuliaFractal((0,0),z>(1,0.2)*sin(z),7,RandomLinearAnalogousHsl(1024,16,21)) 
JuliaSmoothFractal(z,c,dr[,Palette[,DimX[,DimY]]]) JuliaSmoothFractal(z,Lambda,dr[,Palette[,DimX[,DimY]]]) 
As JuliaFractal , except the image is smoothed out using the Heat Equation. Pixels where colors change are used as fixed boundary conditions. 
JuliaSmoothFractal((0,0),(0.785028076171875,0.1465322265625),3,RandomLinearAnalogousHSL(1024,16,2056656298),640,480) JuliaSmoothFractal((0,0),z>(1,0.2)*sin(z),7,RandomLinearAnalogousHsl(1024,16,21)) 
JuliaTopographyFractal(z,c,dr[,Palette[,DimX[,DimY]]]) JuliaTopographyFractal(z,Lambda,dr[,Palette[,DimX[,DimY]]]) 
As JuliaFractal , except only pixels where the color changes are returned, creating a topographical map of the image. 
JuliaTopographyFractal((0,0),(0.785028076171875,0.1465322265625),3,RandomLinearAnalogousHSL(1024,16,2056656298),640,480) JuliaTopographyFractal((0,0),z>(1,0.2)*sin(z),7,RandomLinearAnalogousHsl(1024,16,21)) 
MandelbrotFractal(z,f,dr[,Palette[,DimX[,DimY]]]) 
Calculates a Mandelbrot Fractal Image.  MandelbrotFractal((0.728474426269531,0.240391845703126),,0.000732421875,RandomLinearRGB(4096,128,1325528060),640,480) MandelbrotFractal((1.13804443359375,0.586863875325517),(z,c)>c*(zz^2),6.103515625E05,RandomLinearAnalogousHsl(1024,16,21),400,400) 
MandelbrotSmoothFractal(z,f,dr[,Palette[,DimX[,DimY]]]) 
As MandelbrotFractal , except the image is smoothed out using the Heat Equation. Pixels where colors change are used as fixed boundary conditions. 
MandelbrotSmoothFractal((0.728474426269531,0.240391845703126),,0.000732421875,RandomLinearRGB(4096,128,1325528060),640,480) MandelbrotSmoothFractal((1.13804443359375,0.586863875325517),(z,c)>c*(zz^2),6.103515625E05,RandomLinearAnalogousHsl(1024,16,21),400,400) 
MandelbrotTopographyFractal(z,f,dr[,Palette[,DimX[,DimY]]]) 
As MandelbrotFractal , except only pixels where the color changes are returned, creating a topographical map of the image. 
MandelbrotTopographyFractal((0.728474426269531,0.240391845703126),,0.000732421875,RandomLinearRGB(4096,128,1325528060),640,480) MandelbrotTopographyFractal((1.13804443359375,0.586863875325517),(z,c)>c*(zz^2),6.103515625E05,RandomLinearAnalogousHsl(1024,16,21),400,400) 
NewtonBasinFractal(z,dr,R,c[,N[,DimX[,DimY]]]) 
Creates a Newton basin fractal, coloring attractors found while executing the (generalized) Newton root finding algorithm in the complex plane.  NewtonBasinFractal((0,0),3,,[1,0,0,1]) 
NewtonBuilderFractal(z,dr,R[,Coefficients[,Palette[,DimX[,DimY]]]]) 
Calculates a Newton Fractal Image. When clicked (in a GUI that supports user interaction with resulting images), adds a root to the underying polynomial, instead of zooming in.  NewtonBuilderFractal((0,0),3,) 
NewtonFractal(z,dr,R,c[,Palette[,DimX[,DimY]]]) 
Calculates a Newton fractal.  NewtonFractal((0,0),3,,[1,0,0,0,0,1]) NewtonFractal((pi/2,0),pi/2,2,x>tan(x),RandomLinearRGB(128,4,666001743),800,600) 
NewtonSmoothFractal(z,dr,R,c[,Palette[,DimX[,DimY]]]) 
As NewtonFractal , except the image is smoothed out using the Heat Equation. Pixels where colors change are used as fixed boundary conditions. 
NewtonSmoothFractal((0,0),3,,[1, 0, 0, 0, 0, 1],RandomLinearAnalogousHSL(128,4,746040511),640,480) 
NewtonTopographyFractal(z,dr,R,c[,Palette[,DimX[,DimY]]]) 
As NewtonFractal , except only pixels where the color changes are returned, creating a topographical map of the image. 
NewtonTopographyFractal((0,0),3,,[1, 0, 0, 0, 0, 1],RandomLinearAnalogousHSL(128,4,746040511),640,480) 
NovaFractal(r,i,dr,R,p[,Palette[,DimX[,DimY]]]) 
Calculates a Nova fractal.  NovaFractal(0,0,3,1.5,3,,640,480) 
NovaSmoothFractal(r,i,dr,R,p[,Palette[,DimX[,DimY]]]) 
As NovaFractal , except the image is smoothed out using the Heat Equation. Pixels where colors change are used as fixed boundary conditions. 
NovaSmoothFractal(0,0,3,1.5,3,,640,480) 
NovaTopographyFractal(r,i,dr,R,p[,Palette[,DimX[,DimY]]]) 
As NovaFractal , except only pixels where the color changes are returned, creating a topographical map of the image. 
NovaTopographyFractal(0,0,3,1.5,3,,640,480) 
NovaJuliaFractal(r,i,dr,R,p[,Palette[,DimX[,DimY]]]) 
Calculates a NovaJulia fractal.  NovaJuliaFractal(0,0,0.1,0,3,0.5,5.2,randomlinearrgb(1024,16),640,480) 
NovaJuliaSmoothFractal(r,i,dr,R,p[,Palette[,DimX[,DimY]]]) 
As NovaJuliaFractal , except the image is smoothed out using the Heat Equation. Pixels where colors change are used as fixed boundary conditions. 
NovaJuliaSmoothFractal(0,0,0.1,0,3,0.5,5.2,randomlinearrgb(1024,16),640,480) 
NovaJuliaTopographyFractal(r,i,dr,R,p[,Palette[,DimX[,DimY]]]) 
As NovaJuliaFractal , except only pixels where the color changes are returned, creating a topographical map of the image. 
NovaJuliaTopographyFractal(0,0,0.1,0,3,0.5,5.2,randomlinearrgb(1024,16),640,480) 
NovaMandelbrotFractal(r,i,dr,R,p[,Palette[,DimX[,DimY]]]) 
Calculates a NovaMandelbrot fractal.  NovaMandelbrotFractal(0,0,0.1,0,3,0.5,5.2,randomlinearrgb(1024,16),640,480) 
NovaMandelbrotSmoothFractal(r,i,dr,R,p[,Palette[,DimX[,DimY]]]) 
As NovaMandelbrotFractal , except the image is smoothed out using the Heat Equation. Pixels where colors change are used as fixed boundary conditions. 
NovaMandelbrotSmoothFractal(0,0,0.1,0,3,0.5,5.2,randomlinearrgb(1024,16),640,480) 
NovaMandelbrotTopographyFractal(r,i,dr,R,p[,Palette[,DimX[,DimY]]]) 
As NovaMandelbrotFractal , except only pixels where the color changes are returned, creating a topographical map of the image. 
NovaMandelbrotTopographyFractal(0,0,0.1,0,3,0.5,5.2,randomlinearrgb(1024,16),640,480) 
Iterated Function System (IFS) Fractal functions (Waher.Script.Fractals)
The following functions can be used to create fractal images based on Iterated Function Systems (IFS). The functions are available in the Waher.Script.Fractals
library. They can be used as a means to create backgound images for themes, etc.
Function  Description  Example 

FlameFractalHsl(xc,yc,dr,N,f[,Preview[,Parallel[,DimX[,DimY[,SuperSampling[,Gamma[,LightFactor[,Seed]]]]]]]]) 
Calculates a flame fractal in HSL space. Intensity is mapped along the Laxis. Gamma correction is done along the SLaxes. The Laxis is multiplicated with the LightFactor.  FlameFractalHsl(0.6109375,0.199208333333333,0.625,1e7,[Rotate2DH(45°)*Scale2DH(1/sqrt(2),1/sqrt(2)),"Orange",Translate2DH(1,0)*Rotate2DH(135°)*Scale2DH(1/sqrt(2),1/sqrt(2)),"Red",Identity(2),DiamondVariation(),"Red"],False,False,400,300,1,2.5,2,1668206157) 
FlameFractalRgba(xc,yc,dr,N,f[,Preview[,Parallel[,DimX[,DimY[,SuperSampling[,Gamma[,Vibrancy[,Seed]]]]]]]]) 
Calculates a flame fractal in RGBA space. Intensity is calculated along the Aaxis. Gamma correction is done along the RGBaxes (vibrancy=0) or along the Aaxis (vibrancy=1), or a combination thereof.  FlameFractalRgba(0,0,0,1e7,[Rotate2DH(45°)*Scale2DH(1/sqrt(2),1/sqrt(2)),"Orange",ExponentialVariation(),Translate2DH(1,0)*Rotate2DH(135°)*Scale2DH(1/sqrt(2),1/sqrt(2)),"Red",ExponentialVariation()],400,300) 
IfsFractal(xc,yc,dr,N,T[,DimX[,DimY[,Seed]]]) 
Calculates a fractal based on an Iterated Function System, using the chaos game.  IfsFractal(0,5,6,2e6,[[[0,0,0],[0,0.16,0],[0,0,1]],0.01,"Green",[[0.85,0.04,0],[0.04,0.85,1.6],[0,0,1]],0.85,"Green",[[0.2,0.26,0],[0.26,0.24,1.6],[0,0,1]],0.07,"Green",[[0.15,0.28,0],[0.26,0.24,0.44],[0,0,1]],0.07,"Green"],300,600); 
IfsFractals
run on Iterated Function Systems using systems of linear equations. Flame fractals can modify the linear transforms using one or more variations. There are many different types of variations^{1} that can be used:
Flame variations  Complex variations  Fractal variations 

XVariation 
zCosVariation 
JuliaRoot1Variation 
ArchVariation 
zCubeVariation 
JuliaRoot2Variation 
Bent2Variation 
zDivVariation 
JuliaStepVariation 
BentVariation 
zExpVariation 

BladeVariation 
zLnVariation 

BlobVariation 
zLogNVariation 

BlurVariation 
zMulVariation 

BubbleVariation 
zPowerBaseVariation 

ConicVariation 
zPowerExponentVariation 

CosineVariation 
zSinHVariation 

CrossVariation 
zSinVariation 

CurlVariation 
zSqrtVariation 

CylinderVariation 
zSqrVariation 

DiamondVariation 
zTanHVariation 

Disc2Variation 
zTanVariation 

DiscVariation 
zACosVariation 

ExponentialVariation 
zASinVariation 

EyeFishVariation 
zATanVariation 

Fan2Variation 
zConjugateVariation 

FanVariation 
zCosHVariation 

FishEyeVariation 

FlowerVariation 

GaussianVariation 

HandkerchiefVariation 

HeartVariation 

HorseShoeVariation 

HyperbolicVariation 

JuliaNVariation 

JuliaScopeVariation 

JuliaVariation 

LinearVariation 

NGonVariation 

NoiseVariation 

ParabolaVariation 

PdjVariation 

PerspectiveVariation 

PieVariation 

PolarVariation 

PopcornVariation 

PowerVariation 

RadialBlurVariation 

RaysVariation 

RectanglesVariation 

Rings2Variation 

RingsVariation 

Secant2Variation 

SecantVariation 

SinusoidalVariation 

SphericalVariation 

SpiralVariation 

SquareVariation 

SuperShapeVariation 

SwirlVariation 

TangentVariation 

TwintrianVariation 

WavesVariation 
Persistencerelated functions
The following functions are available in the Waher.Script.Persistence
library.
Function  Description  Example 

DeleteObject(Obj) 
Deletes an object from the underlying persistence layer.  Delete(Obj) 
FindObjects(Type, Offset, MaxCount, Filter, SortOrder) 
Finds objects of a given Type . Offset and MaxCount provide a means to paginate the result set. Filter can be null, if none is used, or a string containing an expression to limit the result set. SortOrder sorts the result. It also determines the index to use. 
FindObjects(Namespace.CustomType, 0, 10, "StringProperty='StringValue'", ["Property1","Property2"]) 
SaveNewObject(Obj) 
Saves a new object to the underlying persistence layer.  SaveNewObject(Obj) 
UpdateObject(Obj) 
Updaes an object in the underlying persistence layer.  UpdateObject(Obj) 
Statisticsrelated functions
The following functions are available in the Waher.Script.Statistics library.
Function  Description  Example 

Beta(Alpha,Beta[,N]]) 
Generates a random number using the Beta distribution. If N is provided, a vector with random elements is returned. 
[Labels,Counts]:=Histogram(Beta(2,5,10000),0,1,10);VerticalBars(Labels,Counts) 
Cauchy(Median,Scale[,N]]) 
Generates a random number using the Cauchy distribution. If N is provided, a vector with random elements is returned. 
[Labels,Counts]:=Histogram(Cauchy(5,1.5,10000),0,10,10);VerticalBars(Labels,Counts) 
Chi2(Degrees[,N]]) 
Generates a random number using the Chi squared distribution. If N is provided, a vector with random elements is returned. 
[Labels,Counts]:=Histogram(Chi2(6,10000),0,20,10);VerticalBars(Labels,Counts) 
Exponential([Mean[,N]]) 
Generates a random number using the Exponential distribution. If no Mean is given, the mean is assumed to be 1. If N is provided, a vector with random elements is returned. 
[Labels,Counts]:=Histogram(Exponential(3,10000),0,10,10);VerticalBars(Labels,Counts) 
Gamma(Shape,Scale[,N]]) 
Generates a random number using the Gamma distribution. If N is provided, a vector with random elements is returned. 
[Labels,Counts]:=Histogram(Gamma(3,3,10000),0,20,10);VerticalBars(Labels,Counts) 
Histogram(V,Min,Max,N) 
Calculates the histogram of a set of data V with N buckets between Min and Max . 
[Labels,Counts]:=Histogram(Uniform(0,10,10000),0,10,10);VerticalBars(Labels,Counts) 
Laplace(Mean,Scale[,N]]) 
Generates a random number using the Laplace distribution. If N is provided, a vector with random elements is returned. 
[Labels,Counts]:=Histogram(Laplace(5,1.5,10000),0,10,10);VerticalBars(Labels,Counts) 
Normal([Mean,StdDev][,N]]) 
Generates a random number using the Normal distribution. If no Mean and standard deviation StdDev is given, the mean is assumed to be 0 and standarddeviation assumed to be 1. If N is provided, a vector with random elements is returned. 
[Labels,Counts]:=Histogram(Normal(0,5,10000),20,20,10);VerticalBars(Labels,Counts) 
StudentT(Degrees[,N]]) 
Generates a random number using the StudentT distribution. If N is provided, a vector with random elements is returned. 
[Labels,Counts]:=Histogram(StudentT(6,10000),5,5,10);VerticalBars(Labels,Counts) 
Uniform([Min,Max][,N]]) 
Generates a random number using the Uniform distribution. If no interval is given, the standard interval _{0,1}is assumed. If N is provided, a vector with random elements is returned. 
[Labels,Counts]:=Histogram(Uniform(0,10,10000),0,10,10);VerticalBars(Labels,Counts) 
Weibull(Shape,Scale[,N]]) 
Generates a random number using the Weibull distribution. If N is provided, a vector with random elements is returned. 
[Labels,Counts]:=Histogram(Weibull(5,3,10000),0,10,10);VerticalBars(Labels,Counts) 
Contentrelated functions (Waher.Script.Content)
The following functions are available in the Waher.Script.Content
library.
Function  Description  Example 

Base64Decode(Data) 
Decodes binary data from a string using BASE64 encoding.  Example 
Base64Encode(Data) 
Encodes binary data to a string using BASE64 encoding.  Example 
Decode(Content,Type) 
Decodes Content using the available Internet Content Type decoder for Content Type Type . 
Example 
Encode(Object[,Types]) 
Encodes Object using the available Internet Content Type encoders. If Types is provided, it is an array of acceptable content types that can be used. The result is a twodimensional vector, containing the binary encoding as the first element, and the content type as the second element. 
Example 
HtmlAttributeEncode(s) 
Encodes a string for inclusion in an HTML attribute. It transforms < , > , & and " to < , > , & and " correspondingly. 
Example 
HtmlValueEncode(s) 
Encodes a string for inclusion as an HTML element value. It transforms < , > and & to < , > and & correspondingly. 
Example 
HttpGet(Url[,Accept/Headers]) 
Retrieves a resource using the HTTP protocol and decodes it, in accordance with its content type. If a second argument is provided, it either represents an Accept header, if a string, or custom HTTP headers, if an object. 
Example 
LoadFile(FileName) 
Loads a file and decodes it, in accordance with its file extension.  Example 
SaveFile(Obj,FileName) 
Encodes an object Obj in accordance with its type and file extension, and saves it as a file. 
Example 
UrlDecode(s) 
Decodes a string taken from an URL.  Example 
UrlEncode(s) 
Encodes a string for inclusion in an URL.  Example 
XmlDecode(s) 
Decodes a string taken from XML. It transforms < , > , & , " and ' to < , > , & , " and ' correspondingly. 
Example 
XmlEncode(s) 
Encodes a string for inclusion in XML. It transforms < , > , & , " and ' to < , > , & , " and ' correspondingly. 
Example 
Markdownrelated functions (Waher.Content.Markdown)
The following functions are available in the Waher.Content.Markdown
library.
Function  Description  Example 

LoadMarkdown(FileName) 
Loads a markdown file and preprocesses it before returning it as a string.  Example 
MarkdownEncode(s) 
Encodes a string for inclusion in Markdown.  Example 
PreprocessMarkdown(MD) 
Preprocesses a markdown string MD , and returns it as a string. 
Example 
The following predefined contextspecific constants (readonly variables) are available in inline script:
Variable  Description 

StartPosition 
The starting position of the current script in the markdown document. 
EndPosition 
The ending position of the script in the markdown document. 
XSLrelated functions (Waher.Content.Xsl)
The following functions are available in the Waher.Content.Xsl
library.
Function  Description  Example 

Transform(XML,XSLT) 
Transforms an XML document using an XSL Transform (XSLT).  Example 
Web Extensions (Waher.Networking.HTTP[.UWP])
Script can be embeded in transformable web content, such as Markdown documents. The following functions are available in the Waher.Networking.HTTP
and Waher.Networking.HTTP.UWP
libraries.
Function  Description  Example 

HttpError(Code,Message,Content) 
Returns an HTTP Error to the client y throwing an HttpException exception. 
HttpError(400,"Bad Request","Missing parameters.") 
In the following subsections, specialized HTTP Error functions are listed.
Redirections
The following functions return HTTP redirection responses back to he client:
Function  Code  Description 

Found(Location)  302  Returns the Found redirection back to the client. 
MovedPermanently(Location)  301  Returns the Moved Permanently redirection back to the client. 
NotModified(Content)  304  Returns the Not Modified message back to the client. 
SeeOther(Location)  303  Returns the See Other redirection back to the client. 
TemporaryRedirect(Location)  307  Returns the Temporary Redirect redirection back to the client. 
UseProxy(Location)  305  Returns the Use Proxy redirection back to the client. 
Client Errors
The following functions return HTTP client error responses back to he client:
Function  Code  Description 

BadRequest(Content)  400  Returns the Bad Request client error message back to the client. 
Conflict(Content)  409  Returns the Conflict client error message back to the client. 
FailedDependency(Content)  424  Returns the Failed Dependency client error message back to the client. 
Forbidden(Content)  403  Returns the Forbidden client error message back to the client. 
Gone(Content)  410  Returns the Gone client error message back to the client. 
Locked(Content)  423  Returns the Locked client error message back to the client. 
MisdirectedRequest(Content)  421  Returns the Misdirected Request client error message back to the client. 
NotAcceptable(Content)  406  Returns the Not Acceptable client error message back to the client. 
NotFound(Content)  404  Returns the Not Found client error message back to the client. 
PreconditionFailed(Content)  411  Returns the Precondition Failed client error message back to the client. 
PreconditionRequired(Content)  428  Returns the Precondition Required client error message back to the client. 
RangeNotSatisfiable(Content)  416  Returns the Range Not Satisfiable client error message back to the client. 
RequestTimeout(Content)  408  Returns the Request Timeout client error message back to the client. 
TooManyRequests(Content)  429  Returns the Too Many Requests client error message back to the client. 
UnavailableForLegalReasons(Content)  451  Returns the Unavailable For Legal Reasons client error message back to the client. 
UnprocessableEntity(Content)  422  Returns the Unprocessable Entity client error message back to the client. 
UnsupportedMediaType(Content)  415  Returns the Unsupported Media Type client error message back to the client. 
Server Errors
The following functions return HTTP server error responses back to he client:
Function  Code  Description 

BadGateway(Content)  502  Returns the Bad Gateway server error message back to the client. 
GatewayTimeout(Content)  504  Returns the Gateway Timeout server error message back to the client. 
InsufficientStorage(Content)  507  Returns the Insufficient Storage server error message back to the client. 
InternalServerError(Content)  500  Returns the Internal Server Error server error message back to the client. 
LoopDetected(Content)  508  Returns the Loop Detected server error message back to the client. 
NetworkAuthenticationRequired(Content)  511  Returns the Network Authentication Required server error message back to the client. 
NotExtended(Content)  510  Returns the Not Extended server error message back to the client. 
NotImplemented(Content)  501  Returns the Not Implemented server error message back to the client. 
ServiceUnavailable(Content)  503  Returns the Service Unavailable server error message back to the client. 
VariantAlsoNegotiates(Content)  506  Returns the Variant Also Negotiates server error message back to the client. 
The following predefined variables are available in such web content files:
Variable  Description 

Request 
The current HttpRequest object. 
Response 
The current HttpResponse object. 
Posted 
Any decoded data posted to the resource. 
Gloabl 
Global variables. 
Page 
Pagelocal variables. 
Gateway Extensions (Waher.IoTGateway)
The following predefined variables are available in web pages hosted by the IoT Gateway:
Variable  Description 

Language 
The language object of the current session. 
Namespace 
The language namespace object of the current page. 
Custom Parsers
The script engine supports custom parses in external modules. Such parses can extend the script engine with new types of constructs in a way function extensions cannot. The following subsections describe such extensions, and the libraries that publish them.
Access to object database
The following extensions are made available by the Waher.Script.Persistence
library.
SELECT
Simplified SQL SELECT
statements can be executed against the object database. Matrices with named columns are returned. Calculated columns are supported. Each record corresponds to an object, and variable references are by default interpreted as members of the current object. To explicitly reference the object, you can use the this
variable. You can also refer to the columns of the result set by using the name of the corresponding column.
Syntax:
SELECT [TOP maxcount]
* 
column1 [name1][, column2 [name2][, ...]]
FROM
type1[, type2[, ...]]
[WHERE
conditions]
[GROUP BY
group1 [groupname1][, group2 [groupname2][, ...]]
[HAVING
groupconditions]]
[ORDER BY
ordercolumn1[ ASCDESC][, ordercolumn2[ ASCDESC][, ...]]]
[OFFSET
offset]
Example:
select
Hour,
count(Type) Nr,
count(Type,EventType.Debug) Debug,
count(Type,EventType.Informational) Informational,
count(Type,EventType.Notice) Notice,
count(Type,EventType.Warning) Warning,
count(Type,EventType.Error) Error,
count(Type,EventType.Critical) Critical,
count(Type,EventType.Alert) Alert,
count(Type,EventType.Emergency) Emergency
from
PersistedEvent
where
Timestamp>=Now.AddDays(1)
group by
DateTime(Timestamp.Year,Timestamp.Month,Timestamp.Day,Timestamp.Hour,0,0) Hour
order by
Hour
Implicit groups
By using aggregate functions in the column definitions, the parser assumes these to be calculated over the entire result set, if no group specification says otherwise. This implicit grouping is used, if any of the following functions are used:
Average
Count
Max
Median
Min
Product
StandardDeviation
Sum
Variance
Example:
select
min(Timestamp) "From",
max(Timestamp) To
from
PersistedEvent
Wildcards
You can also use wildcards (*
) to represent any of the columns in a group. The wildcard also works in implicit groups.
Example:
select
count(*) Nr
from
PersistedEvent
where
Type=EventType.Notice
UPDATE
Simplified SQL UPDATE
statements can be executed against the object database. The number of objects deleted is returned.
Syntax:
UPDATE
type
SET
property=value[,
property2=value2[,...]]
[WHERE
conditions]
Example:
update
PersistedEvent
set
Message="Kilroy "+Message
where
Type=EventType.Notice
DELETE
Simplified SQL DELETE
statements can be executed against the object database. The number of objects updated is returned.
Syntax:
DELETE
FROM
type
[WHERE
conditions]
Example:
delete
from
PersistedEvent
where
Timestamp>=Now.AddDays(1) and
Type=EventType.Informational
Interaction with .NET Code Behind classes
Script can interact with .NET code running in the background. There are different methods to do this:
 Referencing namespaces and types.
 Calling static methods on types.
 Creating objects.
 Calling methods or accessing fields or properties on .NET objects.
Referencing namespaces and types
Root namespaces recognized by the type inventory are available through normal variable references:
System
Subnamespaces are accessed through the member operator .
:
System.Collections.Generic
Types in namespaces are referenced through the member operator .
on its namespace:
System.Guid;
System.Collections.Generic.List
Namespaces and types are values, and can be assigned to variables:
S:=System;
CG:=System.Collections.Generic;
T:=CG.List;
Types and namespaces can be referenced using their unqualified name as long as no other type or namespace share the unqualified name. If multiple types and/or namespaces share an unqualified name, referencing the unqualified name will return an array of qualified names sharing the unqualified name.
Calling static methods on types
Static methods on types are available as method calls using the member operator .
. Parameters in method calls can be included as parameters in the normal fashion:
ID1:=System.Guid.NewGuid();
System.Text.Encoding.UTF8.GetBytes(ID1.ToString())
Creating objects
You can create objects using the Create
function. The first parameter contains the class of the object you want to create. The following arguments contain any (optional) arguments you want to pass on to the constructor:
Create(System.String,"*",10)
If the type is generic, type parameters must also be passed:
L:=Create(System.Collections.Generic.List,System.String)
If a generic type requires parameters in the constructor, these are passed after the type arguments:
Pair:=Create(System.Collections.Generic.KeyValuePair,System.String,System.Object,"A",3)
Calling methods or accessing fields or properties on .NET objects
You can call methods and access fields and properties on an object, using the member operator .
:
L:=Create(System.Collections.Generic.List,System.String);
L.Add("Hello");
L.Add(" ");
L.Add("World!");
n:=L.Count;
L.ToArray();
Physical Quantities
The script supports physical quantities, and can perform unit calculations and unit conversions. This simplifies many tasks such as comparing sensor values or consolidating values from multiple sources using different units. To create a physical quantity, simply write the number (or any expression), followed by the physical unit:
10 m
You can use any SI prefix as well:
10 km
You can use powers as well:
10 m^2
10 m²
10 m³
You can multiply units, using the ⋅
or *
operator:
10 W⋅s
10 W*s
Negative exponents are written either using negative exponents, or by using the /
operator:
10 m⋅s^1
10 m/s
The power operator ^
has higher precedence than ⋅
, *
and /
, so you can combine them safely:
10 m^2/s
10 m/s^2
Use parenthesis (
and )
to group units in the numerator or denominator:
10 kg⋅m²/(A⋅s³)
Unit conversions are done implicitly in code when using addition, subtraction or comparison operators, as long as all values have corresponding units:
10 m + 2 km
2 km  10 m
10 m < 2 km
10 °C > 20 °F
10 m² > 1000 inch²
10 V / 2 A = 5 Ohm
Unit arithmetic, including cancellation of terms, etc., is done when using multiplication or division operators:
2 km * 10 m
2 km² / 10 m
10 m / 2 s
Explicit unit conversion can be performed by providing the unit to convert to behind an expression resulting in a physical quantity:
10 km m = 10000 m
10 kWh kJ = 36000 kJ
In the same way, it is possible to explicitly set the unit of an expression:
10*sin(phi) m
If calling functions or operators normally accepting double values, the unit is stripped and the function or operator evoked with the magnitude of the physical quantity only. Example:
sin(10 W)
Prefixes
All units can be prefixed by any of the following prefixes recognized by the script engine:
Prefix  Name  Scale 

Y  Yotta  10^{24} 
Z  Zetta  10^{21} 
E  Eta  10^{18} 
P  Peta  10^{15} 
T  Tera  10^{12} 
G  Giga  10^{9} 
M  Mega  10^{6} 
k  Kilo  10³ 
h  Hecto  10² 
da  Deka  10¹ 
d  Deci  10^{1} 
c  Centi  10^{2} 
m  Milli  10^{3} 
µ, u  Micro  10^{6} 
n  Nano  10^{9} 
p  Pico  10^{12} 
f  Femto  10^{15} 
a  Atto  10^{18} 
z  Zepto  10^{21} 
y  Yocto  10^{24} 
Note: When there’s an ambiguity of how to interpret a prefix with unit, and the system recognizes a unit with the full name, including the prefix, the full unit will be chosen. Example: ft
will be interpreted as foot, not femtotonnes, min
will be interpreted as minute, not milliinches, etc.
Base Quantities
While any unit can be used to define a physical quantity, unit conversion not based in prefix changes can only be performed on units recognized by the script engine. Such units are defined in base quantities, which are defined in code by creating classes with default constructors implementing the Waher.Script.Units.IBaseQuantity
interface. The following tables lists such base quantities as defined by the Waher.Script
library:
Unit  Meaning 

m  Metre 
Å  Ångström 
inch  Inch 
ft  Feet 
foot  Feet 
yd  Yard 
yard  Yard 
SM  Statute Mile 
NM  Nautical Mile 
Note: Since IN
is a keyword, the unit in has to be written inch
.
Unit  Meaning 

g  Gram 
t  Tonne 
u  Atomic mass unit 
lb  Pound 
Unit  Meaning 

s  Second 
min  Minute 
h  Hour 
d  Day 
w  Week 
Unit  Meaning 

A  Ampere 
Unit  Meaning 

°C, C  Celcius 
°F, F  Farenheit 
K  Kelvin 
Derived Quantities
Apart from the base quantities defined above, and their combinations, exponents and factors, the script engine also handles derived quantities, which are defined in code by creating classes with default constructors implementing the Waher.Script.Units.IDerivedQuantity
interface. The following tables lists such derived quantities as defined by the Waher.Script
library:
Unit  Meaning 

F  1 s^{4}⋅A²/(m²⋅kg) 
Unit  Meaning 

C  1 s⋅A 
Unit  Meaning 

J  1 kg⋅m²/s² 
BTU  1055 Mg⋅m²/s² 
Unit  Meaning 

N  1 kg⋅m/s² 
Unit  Meaning 

Hz  1 s^1 
cps  1 s^1 
rpm  1 min^1 
Unit  Meaning 

W  1 kg⋅m²/s³ 
Unit  Meaning 

Pa  1 kg/(m⋅s²) 
bar  100 Mg/(m⋅s²) 
psi  6894.757 kg/(m⋅s²) 
atm  101352.9279 kg/(m⋅s²) 
Unit  Meaning 

Ω, Ohm, ohm  1 m²·kg/(s³·A²) 
Unit  Meaning 

knot  0.514444 m/s 
kn  0.514444 m/s 
kt  0.514444 m/s 
Unit  Meaning 

V  1 kg⋅m²/(A⋅s³) 
Unit  Meaning 

l  0.001 m³ 
Compound Units
Compound units are units that are written as a string, but in actuality is a sequence of unit factors. The following tables lists compound units recognized by the Waher.Script
library:
Unit  Meaning 

Wh  W⋅h 
Unit  Meaning 

mph  SM/h 
fps  ft/s 
For more information about Flame Fractals and variations, see the paper on The Fractal Flame Algorithm by Scott Daves and Erik Reckase↩