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Edit and Represent Coder Type Objects and Properties

Passing an object to coder.typeof or passing a class name as a string scalar to coder.newtype creates an object that represents the type of object for code generation.

The coder type object displays a succinct description of the object properties while excluding internal state values. Nonconstant properties display their type and size, while constant properties display only their values.

To create a coder type object, pass a compatible object to coder.typeof. For example:

t = categorical({'r','g','b'});
tType = coder.typeof(t)

The representation of variable t is stored in coder type object tType.

tType = 

     1x3 categorical
	Categories : 3x1 homogeneous cell
	   Ordinal : 1x1 logical
	 Protected : 1x1 logical

Object Properties

You can edit the properties of coder type objects. You can assign scalar values to the object properties. Values are implicitly converted to the corresponding coder type values when they are assigned to coder type object properties. The code generator implicitly converts constants assigned to coder type object properties to coder.Constant values. You can resize objects themselves

Resize Objects by Using coder.resize

You can resize most objects by using coder.resize. You can resize objects, its properties and create arrays within the properties.

For example, for a timetable coder object, you can resize the object:

t = timetable((1:5)',(11:15)','SampleRate',1);
tType = coder.typeof(t);
tType = coder.resize(tType, [10 2],[1 0])

This code resizes the timetable to a :10x2 object.

tType = 

     :10x2 timetable
	                Data : 1x2 homogeneous cell
	         Description : 1x0 char
	            UserData : 0x0 double
	      DimensionNames : {'Time'}    {'Variables'}
	       VariableNames : {'Var1'}    {'Var2'}
	VariableDescriptions : 1x2 homogeneous cell
	       VariableUnits : 1x2 homogeneous cell
	  VariableContinuity : 1x2 matlab.internal.coder.tabular.Continuity
	           StartTime : 1x1 matlab.coder.type.DurationType
	          SampleRate : 1x1 double
	            TimeStep : 1x1 matlab.coder.type.DurationType

The constant properties of tType display their values. The nonconstant properties display only their type and size.


Not all types representing MATLAB® classes are compatible with coder.resize.

Resize Objects by Editing Object Properties

You can resize the objects by editing the properties themselves. For a duration coder type object x, edit the Size property to change the size as needed.

x = coder.typeof(duration((1:3),0,0));
x.Size = [10 10]

This code changes the size of the coder type object.

x = 

     10x10 duration
	Format : 1x8 char

You can also make the coder type object variable-size by setting the VarDims flag:

x.VarDims(2) = true

The second dimension of the coder type object is upper-bounded at 10.

x = 

     10x:10 duration
	Format : 1x8 char

Legacy Representation of Coder Type Objects

In R2021a, calling coder.typeof no longer returns a coder.ClassType object. If your workflow requires the legacy representation of coder type objects, use the getCoderType function on the variable that has the new representation of your class or object. For example, to get the legacy representation of a datetime variable, use the variable that has the new representation tt to call the getCoderType function:

t = datetime;
tt = coder.typeof(t);
ttLegacy = tt.getCoderType()

In the Coder Type Editor, the code generator includes the function getCoderType for coder type objects. Use this function to return the legacy representation of coder types. See, Create and Edit Input Types by Using the Coder Type Editor

Certain MATLAB data types provide customized type representations for MATLAB code generation. In other cases, the type is represented using coder.ClassType.

See Also

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