How to plot the ROC curve

Hello. I used this code for plotting the ROC curve:

% Ground truth
GT = imread('reference.tif');
GT = GT == 1; % convert to binary image
P = nnz(GT); % number of positive responses in ground truth
N = nnz(1-GT);

% responses
R = imread('data.tif');
% your thresholds
thresholds = [0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8];
% alternatively, use 100 thresholds between min(R) and max(R)
% thresholds = linspace(min(R(:)), max(R(:)));
% pre-allocate for speed
tp = nan(1, length(thresholds));
fp = nan(1, length(thresholds));
for i = 1:numel(thresholds)
  t = thresholds(end-i+1); % thresholds from high to low as i increases
  Rt = R > t; % thresholded response
  tp(i) = nnz(Rt & GT);
  fp(i) = nnz(Rt & ~GT);
end

% convert to rates
TPR = tp/P;
FPR = fp/N;
plot(FPR, TPR) % ROC

For the attached matlab.zip data it works, but for Results.zip it gave me an empty plot area.

Answer 1

[RAHMANI nadir]

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[FAS]

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