Matlab参数传递绘制ROC曲线

Question

我想用Matlab绘制一条ROC曲线。假设我的真阳性率为3，假阳性率为5.这里的代码我必须绘制ROC曲线。

function [Tps, Fps] = ROC(scores, labels)

%% Sort Labels and Scores by Scores
sl = [scores; labels];
[d1 d2] = sort(sl(1,:));

sorted_sl = sl(:,d2);
s_scores = sorted_sl(1,:);
s_labels = round(sorted_sl(2,:));

%% Constants
counts = histc(s_labels, unique(s_labels));

Tps = zeros(1, size(s_labels,2) + 1);
Fps = zeros(1,  size(s_labels,2) + 1);

negCount = counts(1);
posCount = counts(2);

%% Shift threshold to find the ROC
for thresIdx = 1:(size(s_scores,2)+1)

% for each Threshold Index
tpCount = 0;
fpCount = 0;

for i = [1:size(s_scores,2)]

    if (i >= thresIdx)           % We think it is positive
        if (s_labels(i) == 1)   % Right!
            tpCount = tpCount + 1;
        else                    % Wrong!
            fpCount = fpCount + 1;
        end
    end

end

Tps(thresIdx) = tpCount/posCount;
Fps(thresIdx) = fpCount/negCount;

end

%% Draw the Curve

% Sort [Tps;Fps]
x = Tps;
y = Fps;

% Interplotion to draw spline line
count = 100;
dist = (x(1) - x(size(x,2)))/100;
 xx = [x(1):-dist:x(size(x,2))];

% In order to get the interpolations, we remove all the unique numbers
[d1 d2] = unique(x);
uni_x = x(1,d2);
uni_y = y(1,d2);
yy = spline(uni_x,uni_y,xx);

% No value should exceed 1
yy = min(yy, 1);

plot(x,y,'x',xx,yy);

如何传递此代码的参数？我怎样才能传递我真实的积极和假阳性价值观？请帮助，我是Matlab的新手。