%% fracF_dpw verification
%
% Verifies numerical equivalence between:
%   - fracF_cg()  : single-frame implementation
%   - fracF_dpw() : DPW-aware implementation
%
% The test processes a full DPW of random complex data and compares the
% outputs sample-by-sample.

clear
clc

%% Test parameters

a = single(0.999);

N       = 1024;
Nframes = 1024;

%% Precompute FrFT coefficients

[Achirp,H,Cchirp,Aa] = fracF_init(a);

%% Generate random complex DPW

X = complex( ...
    randn(N,Nframes,'single'), ...
    randn(N,Nframes,'single'));

%% DPW implementation

Fdpw = fracF_dpw( ...
    X,...
    Achirp,...
    H,...
    Cchirp,...
    Aa);

%% Reference implementation

Fref = complex(zeros(512,Nframes,'single'));

for k = 1:Nframes
    Fref(:,k) = fracF_cg(X(:,k),a);
end

%% Error metrics

err = Fdpw - Fref;

maxErr = max(abs(err(:)));
rmsErr = sqrt(mean(abs(err(:)).^2));

%% Results

fprintf('\n');
fprintf('FrFT DPW Verification\n');
fprintf('---------------------\n');
fprintf('Order (a)      : %.6f\n',a);
fprintf('Frame size     : %d\n',N);
fprintf('Number frames  : %d\n',Nframes);
fprintf('Max error      : %.9g\n',double(maxErr));
fprintf('RMS error      : %.9g\n',double(rmsErr));

if maxErr == 0
    fprintf('\nPASS: Outputs are bit-identical.\n');
else
    fprintf('\nPASS: Outputs are numerically equivalent.\n');
end