Week4.predict

function p = predict(Theta1, Theta2, X)
%PREDICT Predict the label of an input given a trained neural network
%   p = PREDICT(Theta1, Theta2, X) outputs the predicted label of X given the
%   trained weights of a neural network (Theta1, Theta2)

% Useful values
m = size(X, 1);
num_labels = size(Theta2, 1);

% You need to return the following variables correctly 
p = zeros(size(X, 1), 1);
X = [ones(size(X,1),1) X];

% ====================== YOUR CODE HERE ======================
% Instructions: Complete the following code to make predictions using
%               your learned neural network. You should set p to a 
%               vector containing labels between 1 to num_labels.
%
% Hint: The max function might come in useful. In particular, the max
%       function can also return the index of the max element, for more
%       information see 'help max'. If your examples are in rows, then, you
%       can use max(A, [], 2) to obtain the max for each row.
%       X: 5000x401;    Theta1: 25x401;    Theta2:10x26
a2 = [ones(1 , size(Theta1 * X',2)) ; sigmoid( Theta1 * X')]; %26x5000
output = sigmoid(Theta2 * a2);   %10x5000
[k p1]=max(output,[],1);
p = p1';
% =========================================================================


end