how to call the data in matrix with the same value in one column

Let's say:

A= [ 111 111 111  2     % group 1  
     999 999 999  2     % group 1 ...........
     555 555 555  4     % group 2   
     222 222 222  4     % group 2 
     333 333 333  4     % group 2 ...........
     123 311 911  7     % group 3 
     221 199 722  7     % group 3 ...........
     699 996 331  8 ]   % group 4

Note: IF the value of column 4 in matrix A is the same, so all data will be grouped in one group

My question is: How to call each group from matrix A? Since, I wanna work with the data in each group? I hope the result:

 A1= [ 111 111 111  2        % point 1
       999 999 999  2]       % point 2

A2= [ 555 555 555  4       % point 3
      222 222 222  4       % point 4
      333 333 333  4 ]     % point 5
.................. and so on.

Answer 1

[KL]

first get all the unique values of column 4 using,

 vals = unique(A(:,4));

then use indexing to filter,

 A(A(:,4)==vals(1),:)

better idea is to use to tables and then use use findgroups

https://de.mathworks.com/help/matlab/matlab_prog/grouping-variables-for-splitting-data.html

[ha ha]

 Thank @KL

You know how to calculate how many point in each group? Exam: group 1 contain 2 points, group 3 contain 3points.