How to sort images into rows?

I want to make a loop that displays images into the groups they are clustered in. Each row should include just the pictures in the group. This is the clusters they are in. For example: Picture 1 is in group 5. clust =

     5
     5
     5
     4
     1
     5
     5
     5
     5
     5
     5
     5
     5
     5
     3
     5
     5
     5
     5
     2

Also below is how I read in the images: for i=1:20 %Reading in the images count=count+1; picnum=num2str(count); im= imread(strcat('/Users/mitchellelmer/Documents/Pictures/20pics/', picnum, '.bmp'));

Answer 1

[Image Analyst]

Use hist() on that vector to find out how many 1's you have, how many 2's you have, ..., how many 5's you have.

[counts, values] = hist(vector);

Then use calculate the number of rows and columns:

rows = length(values); % 5 for this example
columns = max(counts); % 16 for this example, which happens for group 5.

Then you need to call subplot with that number of rows and columns:

subplot(rows, columns, location);

You need to start location at 1 for each cluster and every time you read in an image that belongs to a cluster, increment location. So for cluster (group) #5, location will start at rows*5 and go to rows*5+columns.

So all images from group 1 go into the first row, from group 2 into the second row, etc.

[Mitchell]

 [N,X] = hist(...) also returns the position of the bin centers in X.

I think that would not return the correct numbers.

[Image Analyst]

Perhaps I needed to go into more detail for you to figure it out. Try this:

categories = [5
  5
  5
  4
  1
  5
  5
  5
  5
  5
  5
  5
  5
  5
  3
  5
  5
  5
  5
  2]
numberOfBins = max(categories);
counts = histc(categories, 1:numberOfBins)
rows = length(counts)
columns = max(counts)
location = ones(rows, 1); % Next location in each row.
for k = 1 : length(categories)
  % Read in image
  grayImage = imread('cameraman.tif'); % Use the same image for demo
  % Figure out what category it belongs to.
  thisCategory = categories(k)
  % Determine what row and column it should be displayed in.
  columnForThisImage = location(thisCategory)
  rowForThisImage = categories(k)
  % Get this into a location number that subplot likes.
  thisLocation = columns * (rowForThisImage - 1) + columnForThisImage
  % Specify the destination location.
  subplot(rows, columns, thisLocation);
  % Display the image.
  imshow(grayImage);
  drawnow;
  % Increment what column the next image in this category should be placed into.
  location(thisCategory) = location(thisCategory) + 1;
end
% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);
% Give a name to the title bar.
set(gcf,'name','Demo by ImageAnalyst','numbertitle','off')