Define Categorical Array Inputs - MATLAB & Simulink (original) (raw)

You can define categorical array inputs at the command line or in theMATLAB® Coder™ app. Code generation does not support the programmatic specification ofcategorical input types by using function argument validation (arguments blocks) or by using preconditioning (assert statements).

Define Categorical Array Inputs at the Command Line

Define categorical array inputs at the command line by providing an example input or by using a categorical coder type. You can also specify a constant categorical array input. Alternatively, if you have a test file that calls your entry-point function with example inputs, you can determine the input types by using coder.getArgTypes.

Provide an Example Categorical Array Input

Use the -args option:

C = categorical({'r','g','b'}); codegen myFunction -args {C}

Provide a Categorical Array Type

To provide a type for a categorical array to codegen:

  1. Define a categorical array. For example:
    C = categorical({'r','g','b'});
  2. Create a type fromC.
  3. Pass the type to codegen by using the-args option.
    codegen myFunction -args {t}

Provide a Constant Categorical Array Input

To specify that a categorical array input is constant, use coder.Constant with the -args option:

C = categorical({'r','g','b'}); codegen myFunction -args {coder.Constant(C)}

Representation of Categorical Arrays

The coder type object displays a succinct description of the object properties while excluding internal state values. The command line interface displays the type and size of nonconstant properties and the values of constant properties. For example, create a codercategorical type with a size of 3-by-1.

c = categorical({'r','g','b'}); cType = coder.typeof(c);

The representation of variable c is stored in coder type objectcType.

cType =

matlab.coder.type.CategoricalType 1x3 categorical Categories : 3x1 homogeneous cell Ordinal : 1x1 logical Protected : 1x1 logical

If necessary, you can obtain the legacy coder.ClassType representation of a categorical coder type by using the methodgetCoderType. For example, to view the underlyingcoder.ClassType representation of the cType object, use this command:

ans =

coder.ClassType 1×1 categorical
Properties : codes : :10×1 uint8 categoryNames : :3×1 locked homogeneous cell base: 1×1 char isProtected : 1×1 logical isOrdinal : 1×1 logical numCategoriesUpperBound : 1×1 double

Object Properties

You can edit the properties of coder categorical type objects. You can assign scalar values to object properties. Values are implicitly converted to the corresponding coder type values when they are assigned to coder type object properties. You can resize objects themselves by using the coder.resize function or by editing object properties directly.

Resize Object Properties by Using coder.resize

You can resize categorical objects and object properties by usingcoder.resize. You can also create arrays within properties.

For example, create a coder categorical type with a size of 3-by-1.

c = categorical({'r','g','b'}); cType = coder.typeof(c)

cType =

matlab.coder.type.CategoricalType 1x3 categorical Categories : 3x1 homogeneous cell Ordinal : 1x1 logical Protected : 1x1 logical

Use coder.resize to make Categories variable-length with an upper bound of 3.

cType.Categories = coder.resize(cType.Categories,[3 1],[true false])

cType =

matlab.coder.type.CategoricalType 1x3 categorical Categories : :3x1 homogeneous cell Ordinal : 1x1 logical Protected : 1x1 logical

Resize Objects Directly

You can also resize certain type objects themselves by editing the object properties. For example, to change the number of rows in the cType object, edit theSize property.

cType =

matlab.coder.type.CategoricalType 10x1 categorical Categories : :3x1 homogeneous cell Ordinal : 1x1 logical Protected : 1x1 logical

You can also make the number of rows variable size by using theVarDims property.

cType.VarDims = [true false]

cType =

matlab.coder.type.CategoricalType :10x1 categorical Categories : :3x1 homogeneous cell Ordinal : 1x1 logical Protected : 1x1 logical

See Also

categorical | coder.Constant | coder.typeof | coder.newtype

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