unpack2.m

书籍“Regularization tools for training large feed-forward neural networks using Automatic Differentiat

function [X1,Y1,X2,Y2]=unpack2(x,W1,B1,W2,B2)
%This function unpacks the column vector x into X1,Y1,X2 and Y2.
%Call:
% [X1,Y1,X2,Y2]=unpack2(x,W1,B1,W2,B2)
%
if nargin ~= 5
  error('UNPACK2: Wrong number of arguments');
end
[s1,r]=size(W1);
[s2,s11]=size(W2);
if s1 ~= s11
   error('UNPACK2: Unsyncronized dimensions for W1 and W2')
end
[X1,Y1]=unpack1(x,W1,B1);
for i=1:s1
  X2(:,i)=x(s1*(r+1)+(i-1)*s2+1:s1*(r+1)+i*s2);
end
Y2(:,1)=x(s1*(r+1)+s1*s2+1:s1*(r+1)+s1*s2+s2);