One way to do this would be following:
When you operate on each individual row for finding groups using "findgroups" and mean using "splitapply", you can then use the variable "G" to separate the elements belonging to a specific group and subtract the group mean from each element.
For example,
if 'x' is my 100x120 matrix and x_r is a particular row I am operating on, after using these commands:
>> G = findgroups(x_r);
>> mean_mat = splitapply(@mean,x_r,G);
I can subtract the group mean from each element of that group by using the following commands:
>> x_r(G == 1) = x_r(G == 1) - mean_mat(1);
>> x_r(G == 2) = x_r(G == 2) - mean_mat(2);
.
.
.
If the number of groups are small, you can write these commands separately for each group. Otherwise, you can write a loop to do this for each group:
for(i = 1:max(G))
x_r(G == i) = x_r(G == i) - mean_mat(i);
end
