Tagged Questions

2
votes
1answer
234 views

Precision - Recall: Graphical Representation

I'm a little bit confused with precision recall. I read some papers about recommender systems, where in the one paper they have a graphical representation and in the other papers they don't (they just ...
2
votes
1answer
117 views

Replicating a plot from the ROCR Website

I'm trying to reproduce this plot from the ROCR website: I can get something similar as follows: ...
-1
votes
1answer
1k views

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

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 ...
6
votes
4answers
3k views

How to determine best cutoff point and it`s confidence interval using ROC curve in R?

I have the data of a test that could be used to distinguish normal and tumor cells. According to ROC curve it looks good for this purpose (area under curve is 0.9): My questions are: How to ...
3
votes
1answer
448 views

Plotting overlaid ROC curves

I'm trying to make overlaid ROC curves to represent successive improvements in model performance when particular predictors are added one at a time to the model. I want one ROC curve for each of about ...
14
votes
2answers
340 views

Combining classifiers by flipping a coin

I am studying a machine learning course and the lecture slides contain information what I find contradicting with the recommended book. The problem is the following: there are three classifiers: ...
0
votes
0answers
41 views

ROC curve error [duplicate]

Possible Duplicate: Approxfun error in R while creating an ROC curve - seen this? In the package ROCR with two vectors of binary data, called ...
9
votes
1answer
544 views

Optimising for Precision-Recall curves under class imbalance

I have a classification task where I have a number of predictors (one of which is the most informative), and I am using the MARS model to construct my classifier (I am interested in any simple model, ...
5
votes
1answer
357 views

ROC surfaces in R

If my response variable has 2 levels, 0 and 1, I can use a ROC curve to assess the accuracy of my predictive model. But what if my response variable has 3 levels, -1, 0, and 1? Is there a way to ...