Update ex7 to fix errors

Author: Merouane Atig

mlclass-ex7/bird_small.mat

@@ -107,6 +107,10 @@
 
 %  Load an image of a bird
 A = double(imread('bird_small.png'));
+
+% If imread does not work for you, you can try instead
+%   load ('bird_small.mat');
+
 A = A / 255; % Divide by 255 so that all values are in the range 0 - 1
 
 % Size of the image

mlclass-ex7/ex7.m

@@ -190,6 +190,10 @@
 % Re-load the image from the previous exercise and run K-Means on it
 % For this to work, you need to complete the K-Means assignment first
 A = double(imread('bird_small.png'));
+
+% If imread does not work for you, you can try instead
+%   load ('bird_small.mat');
+
 A = A / 255;
 img_size = size(A);
 X = reshape(A, img_size(1) * img_size(2), 3);

mlclass-ex7/ex7_pca.m

@@ -93,7 +93,7 @@ function submit(partId)
   X = reshape(sin(1:165), 15, 11);
   Z = reshape(cos(1:121), 11, 11);
   C = Z(1:5, :);
-  idx = 1 + mod(1:15, 3);
+  idx = (1 + mod(1:15, 3))';
   if partId == 1
     idx = findClosestCentroids(X, C);
     out = sprintf('%0.5f ', idx(:));

mlclass-ex7/submit.m

@@ -85,7 +85,7 @@ function submitWeb(partId)
   X = reshape(sin(1:165), 15, 11);
   Z = reshape(cos(1:121), 11, 11);
   C = Z(1:5, :);
-  idx = 1 + mod(1:15, 3);
+  idx = (1 + mod(1:15, 3))';
   if partId == 1
     idx = findClosestCentroids(X, C);
     out = sprintf('%0.5f ', idx(:));