getDiscreteStateSpecification

Get the size, data type, and complexity of the discrete state of a System object

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    Syntax

    [size,dataType,complexity] = getDiscreteStateSpecification(obj,propertyName)

    Description

    [size,dataType,complexity] = getDiscreteStateSpecification(obj,propertyName) returns the size, data type, and complexity of the discrete state property. This property must be a discrete state property.

    example

    Examples

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    Call getDiscreteStateSpecification to get the size, data type, and complexity of the discrete state of a System object™.

    Consider a System object object defined as,

    classdef UnitDelay < matlab.System
% UnitDelayNondirect Delay input by one time step

properties(DiscreteState)
        State
        Step
end

    methods(Access = protected)
        function resetImpl(obj)
            obj.State = 0; % Initialize states
            obj.Step = 1;
        end
       
        function [y1, y2] = stepImpl(obj,u)
            y1 = obj.State; % Output current state
            y2 = obj.Step; 
            
            obj.State = u;
            obj.Step = obj.Step + 1; 
        end

        function [sz1, sz2] = getOutputSizeImpl(obj)
            sz1 = [1,1]; % Specify size of output port
            sz2 = [1,1]; 
        end

        function [flag1, flag2] = isOutputFixedSizeImpl(obj)
            flag1 = true; % Specify if output is fized size
            flag2 = true;
        end

        function [c1, c2] = getOutputDataTypeImpl(obj)
            c1 = 'double'; % Specify output datatype
            c2 = 'double'; 
        end 

        function [c1, c2] = isOutputComplexImpl(obj)
            c1 = false;   % Specify if output is complex
            c2 = false; 
        end

        function [sz,dt,cp] = getDiscreteStateSpecification(obj,name)
            sz = [1 1];
            dt = "double";
            cp = false;
        end


end

    Create an instance of the System object and provide it with an input.

    a = UnitDelay();
[out, step] = a(1);

    Call getDiscreteStateSpecification to check the specification of the 'Step' state.

    [sz,dt,cp] = getDiscreteStateSpecification(a,"Step");

    Input Arguments

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    System object handle used to access properties, states, and methods specific to the object.

    Name of discrete state property of the System object

    Output Arguments

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    Vector containing the length of each dimension of the property.

    Data type of the property. For built-in data types, dataType is a character vector. For fixed-point data types, dataType is a numeric type object.

    Complexity of the property as a scalar, logical value:

    • true — complex

    • false — real

    Version History

    Introduced in R2012a

    See Also