How to group arrays in matrix

Matrix A as follows:

A = [
1
1
1
2
2
4
4
7
8
8
9
];

I want to group by matrix A as follows:

B = [
1 3
2 2
4 2
7 1
8 2
9 1
];

[Stephen23]

The old fashioned way:

>> U = unique(A);
>> [U,hist(A,U).']
ans =  
   1   3
   2   2
   4   2
   7   1
   8   2
   9   1

Answer 1

[Thorsten]

If the second row is the number of occurrences then you can use

 [a, ~, c] = unique(A);
 B = [a, accumarray(c, 1)];

Answer 2

[Guillaume]

A = [1 1 1 2 2 4 4 7 8 8 9]'

B = unique(A);
B = [B, histcounts(A, [B; Inf]).']