how to count the occurrences of a value for an matrix?

a= [ 3 4 5; 7 8 9; 3 6 8 ; 4 6 9; 3 6 5]

I expected the ans:

b=

[ 3 3
   4 2
   5 2
   7 1
   8 2
   9 2
   6 3]

all the values must displays the number of occurences

Answer 1

[lvn]

c=unique(a);
b=[c, sum(bsxfun(@eq,a(:),c'))']

b =

     3     3
     4     2
     5     2
     6     3
     7     1
     8     2
     9     2

Answer 2

[Image Analyst]

What you're describing is the histogram. You can use the histc() function to get the counts, and then stitch the bins and counts together to get the "b" variable you want.

a = [ 3 4 5; 7 8 9; 3 6 8 ; 4 6 9; 3 6 5]
bins = unique(a);
counts = histc(a(:), bins);
b = [bins, counts]