Question

I’ve tried using the function like this:

AUC(WM,time=Grand.trial,id=Feed,dv=Distance.moved)

but it results in this error message:

Error in (function(x, i, exact) if (is.matrix(i)) as.matrix(x)[[i]] else .subset2(x,  : 
object 'Feed' not found

I tried specifying the dataset for the object (WM$Feed instead of just Feed), but then I just get another error:

Error in .subset2(x, i, exact = exact) : 
recursive indexing failed at level 2

Can anyone help? Other ways to compute the AUC (trapezoid method) are just as welcome

Answer 1

An example using the ROCR package:

> library(ROCR)
> data(ROCR.simple)
> pred <- prediction( ROCR.simple$predictions, ROCR.simple$labels)
> performance(pred, 'auc')@y.values
[[1]]
[1] 0.8341875