Re: [R] nnet classification accuracy vs. other models

2004-03-15 Thread Christian Hennig
My experience is that nnet needs a lot of tuning, not only in terms of numbers of layers, but also in terms of the other parameters. My first results where I kept very much of the default parameter values with nnet have been very bad, as bad as you say. (But as Brian Ripley already wrote, it's not

Re: [R] nnet classification accuracy vs. other models

2004-03-14 Thread Prof Brian Ripley
On Sun, 14 Mar 2004, Albedo wrote: > The only thing that I could have done wrong with nnet > (that I > can think of) is not enough nuerons in hidden layer, > but then > again this is actually limited by my computer memory. Perhaps you had too many, not too few? Perhaps you didn't choose the we

Re: [R] nnet classification accuracy vs. other models

2004-03-14 Thread Albedo
The only thing that I could have done wrong with nnet (that I can think of) is not enough nuerons in hidden layer, but then again this is actually limited by my computer memory. However, I did estimate the error a little bit different - I have enough data for test set, which I used for classifica

Re: [R] nnet classification accuracy vs. other models

2004-03-13 Thread Edgar Acuna
I think that you are using nnet incorrectly. I have compared several classifiers (including that ones that you mention in your e-mail) on the same dataset and I have never found more of a 20% of difference in the missclassification error. Of course, I estimated the misclassification error by cross

[R] nnet classification accuracy vs. other models

2004-03-13 Thread Albedo
I was wandering if anybody ever tried to compare the classification accuracy of nnet to other (rpart, tree, bagging) models. From what I know, there is no reason to expect a significant difference in classification accuracy between these models, yet in my particular case I get about 10% error rate