getOutputSizeImpl

Class: matlab.system.mixin.Propagates
Package: matlab.system.mixin

Sizes of output ports

Syntax

[sz_1,sz_2,...,sz_n] = getOutputSizeImpl(obj)

Description

[sz_1,sz_2,...,sz_n] = getOutputSizeImpl(obj) returns the size of each output port. The number of outputs must match the value returned from the getNumOutputs method or the number of output arguments listed in the stepImpl method.

If your System object™ has only one input and one output and you want the input and output sizes to be the same, you do not need to implement this method. In this case getOutputSizeImpl assumes that the input and output sizes are the same and returns the size of the input. For variable-size inputs in MATLAB^®, the size varies each time you run your object. For variable-size inputs in Simulink^®, the output size is the maximum input size.

You must implement the getOutputSizeImpl method to define the output size, if:

Your System object has more than one input or output
You need the output and input sizes to be different.
If the output size differs from the input size, you must also use the propagatedInputSize method

During Simulink model compilation and propagation, the MATLAB System block calls the getOutputSizeImpl method to determine the output size.

All inputs default to variable-size inputs For these inputs, the output size is the maximum input size.

Note

You must set Access = protected for this method.

In this method, you cannot modify any properties.

Input Arguments

obj

System object handle

Output Arguments

sz_1,sz_2,...

Vector containing the size of each output port.

Examples

expand all

Specify Output Size

Specify in your class definition file the size of a System object output.

methods (Access = protected)
   function sz_1 = getOutputSizeImpl(obj)
      sz_1 = [1 1];
   end 
end

Specify Multiple Output Ports

Specify in your class definition file the sizes of multiple System object outputs.

methods (Access = protected)
   function [sz_1,sz_2] = getOutputSizeImpl(obj) 
      sz_1 = propagatedInputSize(obj,1); 
      sz_2 = [1 1]; 
   end
 end

Specify Output When Using Propagated Input Size

Specify in your class definition file the size of System object output when it depends on the propagated input size.

methods (Access = protected)
   function varargout = getOutputSizeImpl(obj) 
      varargout{1} = propagatedInputSize(obj,1); 
      if obj.HasSecondOutput
         varargout{2} = [1 1];
      end
   end
end

Documentation