Linked Questions

0
votes
2answers
1k views

ROC accuracy measure error when no positive values

I have an unbalanced dataset that I am working to either up or down sample to balance out. But in the meantime I've run into an interesting error when calculating the AUC in R using ...
0
votes
1answer
1k views

ROC AUC and PR AUC: Are the AUC values different for each class?

When dealing with a binary classification problem, where the decision function threshold is being varied from 0 to 1 at step 0.1: When calculating the Area Under the Curve (AUC) for a ROC Curve plot (...
1
vote
1answer
593 views

Determining the validity of ROC curves

ROC curves were generated using ROCR package using only actual and predicted labels(from a SVM) as input. Script: ...
0
votes
1answer
204 views

Logistic-regression probability score used for reordering rows for plotting ROC curve: is it the actual, positive, or negative class probability?

I want to draw my own ROC curve, such as explained in the accepted answer to this question: Understanding ROC curve However, it isn't clearly explained what the 'score' used represents. It is used ...
1
vote
1answer
94 views

ROC Curve Horizontal Line

I'm trying to conceptually understand 'why' the horizontal gray line in ROC curve below would be considered random. I know the basics of the ROC in that the farther the curved black line is from the ...
2
votes
0answers
114 views

How to calculate the prediction score of a classificator?

I want to compare a given classification algorithm with others via the Area under the (ROC-)curve metric. Unfortunately this algorithm only outputs the values of the respective confusion matrix (TP, ...
2
votes
1answer
83 views

SVM: achieving ROC curve by varying misclassification costs

Assume that we have SVM model for binary classification with objective function as follows: $$ min(\frac{1}{2}\omega\cdot\omega +C^{+}\sum_{i|y_{i}=+1}^{n}\xi_{i}\quad+C^{-}\sum_{i|y_{i}=-1}^{n}\xi_{i}...
0
votes
0answers
16 views

Should I calculate the classification performances (AUROC etc) before or after the neural network calibration?

Should I calculate the classification performances (AUROC, AUPR etc) before or after the neural network calibration (using for ex. isotonic regression)?

15 30 50 per page
1
2