# compute ROC from Sensitivity and Specificity

It might sound like a stupid question, but I've got to ask it. Let's say I have a classifier, with one discrete bounded parameter. I have run the classifier over all possible parameter values, and computed sensitivity specificity and accuracy for each parameter value.

Is there a way to compute the ROC curve from this list of measures?

I tried to plot ( sensitivity, 1-specificity ) but the result is a line crisscrossing itself many times.