r - Response and predictor must be vectors of the same length -

i'm using proc curve in order compare performance of models. have plotted 4 svm models. when plot decision tree model following error:

error in roc.default(x, predictor, ...) :    response , predictor must vectors of same length. 

the following code represent how plotted curve:

rocobj1 <-plot(roc(as.numeric(video.test$rate),as.numeric(svm.grossesse.pred4)),main="comparaison ",col="#1c61b6") rocobj5 <-lines.roc(as.numeric(video.test$rate),as.numeric(predarbredecision),col="pink")