jit.expr Reference

Evaluate an expression to fill a matrix



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.



Note: The jit.op operators >p and <p are not recognized by the jit.expr parser. The expressions gtp( x , y ) and ltp( x , y ) may be used in their place.

Expressions should be specified between double quotes, and different expressions can be evaluated 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 arithmetic, 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 evaluated 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

More about Matrix Operators

The Jitter MOP

MOP Arguments

MOP Attributes

MOP Messages


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 [32 symbols]

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.

inputs [int]

Input count (default = 2). Please note, there is no inlet support for this attribute. Changing the input count via an attrui, message, or the inspector will not work. You can only change the input count by typing the attribute into the object box.

precision [symbol]

Sets the internal precision. The options are:

float32 (the default)

verbose [int]

Toggles the printing of expression information to Max Console.

Common Box Attributes



Sets all matrix cells corresponding with input to int.


Sets all matrix cells corresponding with input to float.



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

See Also

Name Description
Working with Video in Jitter Working with Video in Jitter
Tutorial 39: Spatial Mapping Tutorial 39: Spatial Mapping
Tutorial 46: Manipulating Matrix Data using JavaScript Tutorial 46: Manipulating Matrix Data using JavaScript