Neural Network Toolbox

softmax

Soft max transfer function

Graph and Symbol

Syntax

A = softmax(N)

info = softmax(code)

Description

softmax is a transfer function. Transfer functions calculate a layer's output from its net input.

softmax(N) takes one input argument,

• N -- S x Q matrix of net input (column) vectors

and returns output vectors with elements between 0 and 1, but with their size relations intact.

softmax('code') returns information about this function.

These codes are defined:

• 'deriv' -- Name of derivative function.

  'name' -- Full name.

  'output' -- Output range.

  'active' -- Active input range.

compet does not have a derivative function.

Examples

Here we define a net input vector N, calculate the output, and plot both with bar graphs.

• n = [0; 1; -0.5; 0.5];
  a = softmax(n);
  subplot(2,1,1), bar(n), ylabel('n')
  subplot(2,1,2), bar(a), ylabel('a')
  

Network Use

To change a network so that a layer uses softmax, set net.layers{i,j}.transferFcn to 'softmax'.

Call sim to simulate the network with softmax. See newc or newpnn for simulation examples.

See Also

sim, compet

sim

srchbac

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