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jit.expr

Evaluate expressions

Description

The jit.expr object evaluates expressions to fill an output matrix. The expression can contain any operator available from within jit.op, any functor available from within jit.bfg, and many jitter MOPs. A variable number of inputs can be specified with an attribute argument setting the inputs attribute. Expressions should be specified between double quotes, and different expressions can be evaulated per plane if multiple symbols are used for the expr attribute. There are special variables and constants which can be used within expressions listed below. All expressions are evaluated using floating point arithmeic, so they will be more precise, but often slower for computing char data. For optimal speed with char data, it is recommended to use jit.charmap where possible (perhaps filled with an exaluated expression).

Matrix Operator

matrix inputs:-1, matrix outputs:1

Name	IOProc	Planelink	Typelink	Dimlink	Plane	Dim	Type
out	n/a	1	1	1	1	1	char long float32 float64

Information for Jitter Matrix Operator (MOP) messages and attributes to this object

Messages

int		Sets all matrix cells corresponding with input to int.
float		Sets all matrix cells corresponding with input to float.
list	input [list]	Sets all matrix cells corresponding with input to list, on a per plane basis.

Attributes

Name	Type	g/s	Description
inputs	int		Input count (default = 2)
cache	int		Toggles the cache intermediary values flag. The default is 1 (on). It may be desirable to turn off when using generator operators such as jit.noise in the expression, which should not be cached.
expr	symbol		The expression to evaluate. If one expression is specified, it is evaluated for all planes. If multiple expressions are specified, they are evaluated on a plane by plane basis. For a list of valid operators see jit.op and jit.bfg. Special variables that may be used are: cell[0-31] integer coordinate across dim norm[0-31] normalized coordinate across dim snorm[0-31] signed normalized coordinate across dim dim[0-31] matrix size across dim in[0-31] input matrix, corresponding plane in[0-31].p[0-31] input matrix, specific plane matrixname any named matrix, corresponding plane matrixname.p[0-31] any named matrix, specific plane Special contants that may be used are: PI TWOPI HALFPI INVPI 1/PI DEGTORAD TWOPI/360 RADTODEG 360/TWOPI E Euler's constant LN2 natural log of 2 LN10 natural log of 10 LOG2E log base 2 of Euler's constant LOG10E log base 10 of Euler's constant SQRT2 square root of 2 SQRT1_2 square root of 1/2
precision	symbol		Sets the internal precision. The options are: float32 (the default) float64
verbose	int		Toggles the printing of expression information to Max Window.

Information for box attributes common to all objects

Examples

See Also

Name	Description
expr	Evaluate a mathematical expression
jit.charmap	256 point input to output map
jit.op	Apply binary or unary operators
jit.bfg	Evaluates a procedural basis function graph
vexpr	Evaluate a math expression for a list of different inputs
Tutorial 39: Spatial Mapping	Tutorial 39: Spatial Mapping
Tutorial 46: Manipulating Matrix Data using JavaScript	Tutorial 46: Manipulating Matrix Data using JavaScript