MATLAB: Using arrayfun on 2d matrix

MATLABmatrixvectorization

for i = 1:D
  Xtr = arrayfun(@(x) binarize(x, threshold), Xtrn(:, i));
end
Xtrn is a MxD matrix
Xtr is a MxD matrix

Can we vectorize this loop as well?

This is what binarize does

function X = binarize(X, threshold)
  if(X<threshold)
  X = 0;
  else
  X = 1;
  end
end

You are overwriting all of Xtr in each iteration of i

You probably just want

Xtr = binarize(Xtrn, threshold)

with

function b = binarize(X, threshold)
  b = X >= threshold;

First, I would label regions in your image:

   bwl = bwlabel(img,8);

Area of regions:

   a = regionprops(img,'area');
   a = {a.Area}; %turn into cell array

Create a mask for what you want to be dilated:

   xarea = 10;
   idx = find(cellfun(@(x)x<xarea,a));
   bwl2 = sum(reshape(cell2mat(arrayfun(@(x)x==bwl,idx,'un',0)),size(img,1),size(img,2),[]),3);

Dilate the mask:

   bwl2 = bwmorph(bwl2,'dilate',1);

And finally, apply this dilated mask back to the original bw image:

   img = img | bwl2;

Please go back and reformat your question. Use the button that looks like this:

{} Code

on the code you pasted in the window.

Now, this is not an ARRAYFUN error but an ISEQUAL error. ISEQUAL takes two arguments.

isequal(9,8)
isequal(pi,pi)

What are you trying to compare? Do you mean this:

d= arrayfun(@(x) eq(x.x0,t1.x0),g1,'Un',0)