To obtain the coefficient value matrix Transforma​tionDelayM​atrix1 for for a method of a class definition NewtonRateConverter

I have tried to defined a class definition

classdef (StrictDefaults)NewtonRateConverter< dsp.FarrowRateConverter &...
        dsp.internal.SupportScalarVarSize & ...
        dsp.internal.MultirateEngine &...    
        dsp.internal.FilterAnalysisMultirate 
    
    %Constructor 
    methods
        
        function obj = NewtonRateConverter(varargin)
            % Constructor for the NewtonRateConverter class
            setProperties(obj, nargin, varargin{:}, ...
                'InputSampleRate', ...
                'OutputSampleRate', ...
                'OutputRateTolerance', ...
                'PolynomialOrder');
        end
    end

basically it overrides the Farrow Rate Converter and introduce certain conversions over it .

Now for it two Transformation Delay Matrices Td1 and Td2 are required.Mathematically Td1

M is the Polynomial Order

So I created function file for Td1

    function Td1 = compute_Td1(M)
        % Create a matrix of binomial coefficients
        [I, J] = ndgrid(1:M, 1:M);
        binomials = zeros(M, M);
        for i = 1:M
            binomials(i, 1:i) = arrayfun(@(ii, jj) nchoosek(ii-1, jj-1), I(i, 1:i), J(i, 1:i)); 
        end
        % Create a matrix for powers
        powers = ((- (M - 1) / 2) .^ (I - J)) .* (J <= I);
        % Element-wise multiplication to get Td1
        Td1 = binomials .* powers;
    end

This I defined as a static method in NewtonRateConverter

>> compute_Td1(3)

ans =

1 0 0

-1 1 0

1 -2 1

>> compute_Td1(5)

ans =

1 0 0 0 0

-2 1 0 0 0

4 -4 1 0 0

-8 12 -6 1 0

16 -32 24 -8 1

I entered this as a function as a property and method in this class definition NewtonRateConverter

    properties
        TransformationDelayMatrix1
        PolynomialOrder
    end
    methods
        function computeTransformationDelayMatrix1(obj)
            % Access PolynomialOrder from superclass
            
            M = obj.PolynomialOrder;
            
            % Compute TransformationDelayMatrix1 using compute_Td1
            obj.TransformationDelayMatrix1 = compute_Td1(M);
        end
    end

When I tried to access this object TransformationDelayMatrix1

    % Initialization
    myNRC = NewtonRateConverter('InputSampleRate', 44100, 'OutputSampleRate', 48000, 'PolynomialOrder', 3);
    myNRC.TransformationDelayMatrix1

In the command window it displays :

>> myNRC.TransformationDelayMatrix1

ans =

[]

Why is this an empty array shown please could you clear out this doubt ?Please could you debugg ?

[Walter Roberson]

Duplicated (it appears) by https://www.mathworks.com/matlabcentral/answers/2165754-to-obtain-the-coefficient-value-matrix-transformationstatedelaymatrix-for-for-a-method-of-a-class-d?s_tid=srchtitle

Answer 1

[Walter Roberson]

Your code does not call computeTransformationDelayMatrix1 anywhere, so TransformationDelayMatrix1 is going to be the default []