[R] Strange error with ROCR
chschulz at email.de
Tue Aug 4 12:28:39 CEST 2009
you need the score value , have a look at ?svm.predict and in the ROCR
traindata <- as.data.frame(matrix(runif(1000),ncol=10))
model <- svm(traindata,trainlabels, type="C-classification",
class.weights=c("win"=3,"lose"=1), scale=FALSE, probability = TRUE)
prediction <- predict(model, traindata, decision.values = TRUE,
probability = TRUE)
probs <- attr(prediction, "probabilities")[,1]
pred <- prediction(probs,trainlabels)
> I've come across a strange error...
> Here is what happens:
> model <- svm(traindata,trainlabels, type="C-classification",
> kernel="radial", cost=10, class.weights=c("win"=3,"lose"=1),
> scale=FALSE, probability = TRUE)
> predictions <- predict(model, traindata)
> pred <- prediction(predictions, trainlabels)
> This returns an error:
> Error in prediction(predictions, trainlabels) :
> Format of predictions is invalid.
> Yet my predictions is just a matrix of predicted labels. Nothing
> fancy. (In fact, my step follow the exact example on the ROCR homepage.)
> A search through google for "Format of predictions is invalid" returns
> zero results.
> Can anyone suggest how I might fix this problem?
> Thank You,
> [[alternative HTML version deleted]]
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