Problem with plotting graph

Hello, I trained Fast R-cnn detector and after I visualize graph of average precision for every class, each graph looks the same but the value of average precision is diferent for every class...

here is the code:

[ap, recall, precision] = evaluateDetectionPrecision(detectionResults,testData);

here i am showing average precision for first class:

recallv = cell2mat(recall);
precisionv = cell2mat(precision);
[r,index] = sort(recallv);
p = precisionv(index);
figure
plot(r,p)
xlabel("Recall")
ylabel("Precision")
grid on
title(sprintf("Average Precision = %.2f",ap(1)))

and the graphs looks the same for every class:

and also average precision for 4th class is 0... I dont know why... can anybody help me? why is the average precision for 4th class 0?

[Walter Roberson]

recallv = cell2mat(recall);
precisionv = cell2mat(precision);

That looks like you are combining all of the results. I would have expected one plot per cell entry.

[Adrian Kleffler]

So what should i do?

[Walter Roberson]

for i = 1 : length(ap)
    recallv = recall{i};
    precisionv = precision{i};
    stuff goes here
    title(sprintf("Average Precision = %.2f",ap(i)));
end

[Adrian Kleffler]

Can you insert it in my code please? I’m not sure if i understand you

Answer 1

[Walter Roberson]

for i = 1 : length(ap)
    recallv = recall{i};
    precisionv = precision{i};
    [r,index] = sort(recallv);
    p = precisionv(index);
    figure
    plot(r,p)
    xlabel("Recall")
    ylabel("Precision")
    grid on
    title(sprintf("Average Precision = %.2f",ap(i)));
end

However you might want to consider using subplot() or tiledlayout() to put multiple plots in the same figure instead of using individual figures.

[Adrian Kleffler]

thank you so much!