Re: [theano-users] Softmax is a classifier?

2016-11-24 Thread Pascal Lamblin
The softmax layer (softmax(wx + b) is a classifier, that is trained on
the last fully-connected layer, and backpropagates a gradient so that
the rest of the network is trained as well.

SVM is a different classifier, that they connected to the same input
(x, the output of the last fully-connected layer) and that they trained
(without backpropagation I think).

There is sometimes confusion in the literature between the softmax
operation itself (exp(x) / exp(x).sum(), that converts unnormalized
log-probabilities into a probability vector) and the "softmax layer", or
"logistic regression layer" (softmax(Wx+b)).

On Thu, Nov 24, 2016, Beatriz G. wrote:
> Hi Everyone, I am trying to build a cnn based in imagenet. The paper which 
> I am following sais that the architecture is formed by convolutional layers 
> and fully connected layers, and in the last layer, i.e. output layer is 
> followed by softmax. Then, it sais that after extracting the features from 
> the last fully connected layer, uses a SVM as a classifier.
> 
> I do not know if the input of the classifier is the output of the softmax.
> 
> And I thought that the softmax was a classifier, and I must be wrong
> 
> 
> Regards.
> 
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Pascal

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[theano-users] Softmax is a classifier?

2016-11-24 Thread Beatriz G.
Hi Everyone, I am trying to build a cnn based in imagenet. The paper which 
I am following sais that the architecture is formed by convolutional layers 
and fully connected layers, and in the last layer, i.e. output layer is 
followed by softmax. Then, it sais that after extracting the features from 
the last fully connected layer, uses a SVM as a classifier.

I do not know if the input of the classifier is the output of the softmax.

And I thought that the softmax was a classifier, and I must be wrong


Regards.

-- 

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