Question

In other words, when I do nnet(...) I can use the size parameter to control the number of units in the hidden layer. My particular model requires outputting probabilities so I wanted logistic units and so I turned to multinom from the nnet package to output type=’probs’ in my predict function. How can I pass down a size argument? When I call it with, say, size=5 or something I get an error:

 formal argument "size" matched by multiple actual arguments

Answer 1

multinom fits linear multinomial logistic models, which is why the size parameter is hardcoded to 0. If you want an actual neural network with multinomial outputs, just use nnet with a response with more than 2 levels, and set softmax=TRUE.