How to plot ROC curve with TP, FP and FN alone with different thresholds?

Question

I want to plot a ROC for my detection algorithm which is used to detect features in image. I had obtained true positive, false positive and false negative from the algorithm. There is no true negative in my case.

   I had run the algorithm for 6 images so i got 6 number of TP,FP and FN. With

this how can i plot the ROC curve.

Threshold 1

TP    FP    FN
1066  70    116
1176  67    201
890   42    129
1040  69    74
677   88    94
1284  73    123

Threshold 2

TP  FP  FN
446 41  55
180 15  42
221 16  62
304 23  56
170 39  23
310 31  74

I am new to ‘R’, so I also need to know how to plot it in R?

Answer 1

There are R packages that already implemented what you are trying to achieve, e.g. ROCR. If you want to implement it yourself I'd suggest that you familiarize yourself with ROC curves first, for instance by reading the following paper:

Fawcett, T. (2006). An introduction to ROC analysis. Pattern Recognition Letters, 27(8), 861–874.