How to save certain values in a FOR loop

Hi, i am running several FOR-loops, as shown below, and want to save the step-values which satisfies the if-command. Right now I just stop the script at the first values which satisfies the criteria, but as there propably will be more than one answer, I would like to save all the different combinations in a matrix, or a file. How do I do this?

 for k = 17.12:0.001:17.13 
    for c0 = 0.1:0.1:0.5
        for c1 = 1:1:5
            for ac = 0.1:0.1:0.5
                for mc = 0.2:0.1:0.7
                    for a = 0:0.1:0.2
                        for m = 0:0.1:1
        propellerdesign;
        %This is the main script which runs as it should
                            if T_req<= T && T <= 1.001*T_req && cav_points == 0
                            return
                            end
                        end
                    end
                end
            end
        end
    end
end

Answer 1

[Elias Gule]

just before the start of the first for loop, define an empty matrix, this will be the storage for all the valid step-values. Replace the return statement with a statement that updates your storage matrix.

m = [];
for k = 17.12:0.001:17.13 
  for c0 = 0.1:0.1:0.5
      for c1 = 1:1:5
          for ac = 0.1:0.1:0.5
              for mc = 0.2:0.1:0.7
                  for a = 0:0.1:0.2
                      for m = 0:0.1:1
      propellerdesign;
      %This is the main script which runs as it should
                          if T_req<= T && T <= 1.001*T_req && cav_points == 0
                          m = [m T_req]; % This causes your matrix to expand as necessary
                          end
                      end
                  end
              end
          end
      end
  end
end

[Elias Gule]

Alternatively, you can do the following:

valid_count = 0
m = nan*ones(10000,1) % A column vector of 10000 nans

%% Replace m = [m T_req] with the following lines

valid_count = valid_count + 1
m(valid_count) = T_req

%% After the loops, type the following

m = m(~isnan(m)) % Removes all the nan entries in from the matrix m

[Anna]

Thank you so much! the second alternative worked out great :)

[Manu K Sajan]

Finallly!!!! after lots of googling, this method works perfectly!!!Thanks