I have three columns containing data. I want to isolate particular data depending on the third column and find the maximum values on the second column for each case of the isolated data from the third column.

I have a matrix with the following form:

    A = [1 2 3; 2 2 6; 0 1 3; 0 4 3]

I want for each unique case from the third column, to find the maximum values on the first and the second columns.

Answer 1

[Michael Madelaire]

Hi, hope this works.

The first column shows the max in the first column.

The second column shows the max in the second column.

The third column shows the unique values in AA.

    A = [1 2 3; 2 2 6; 0 1 3; 0 4 3];
[values, tag, places] = unique(A(:, 3));
AA = zeros(length(values), 3);
AA(:, 3) = values;
for i = 1:length(values)
    AA(i, 1) = max(A(places == tag(i), 1));
    AA(i, 2) = max(A(places == tag(i), 2));
end