On 20 Oct 2003, Rajarshi Guha wrote: > Hi, > I was trying to use the nnet library and am not sure of whats going > on. I am calling the nnet function as: > > n <- nnet(x,y,size=3,subset=sets[[1]], maxit=200) > > Where x is a 272x4 matrix of observations (examples) and y is a 272x1 > matrix of target values. However when I look at nnet$residuals they are > off by two orders of magnitude (compared to the output from neural > network code that I already have). Looking at nnet$fitted.values shows > all the values to be 1 (whereas my target values range from 0 to 150). > > Am I making an obvious mistake in the way I'm calling the function? Is > the fact that n$fitted.values is all 1's indicating that the NN is doing > a classification? If so how can I make it do quantitation?
Yes, so please do read the help page accurately. > The man page mentions that if the response is a factor then it defaults > to quantitation. However my y matrix just contain numbers - so it > should'nt be doing classification. That's incorrect reading of the help page, which actually says If the response in 'formula' is a factor, an appropriate classification network is constructed; this has one output and entropy fit if the number of levels is two, and a number of outputs equal to the number of classes and a softmax output stage for more levels. If the response is not a factor, it is passed on unchanged to 'nnet.default'. and you did not give a formula. As someone else said recently. those who write the manuals don't expect to either read them for you nor re-write them here, so please show more consideration for their work. -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help