How to plot x-y coordinates which correspond to elements which are repeated at least once
My project concerns capture & recapture of rats. I have a 1040 x 3 array, the first column is the tag number of the rat (when each rat is captured for the first time, its given a tag (harmlessly of course!) the other 2 columns are the x & y coordinates respectively of where in a 7x7 plane the rat was captured. If the same rat is captured again, its position is then recorded again. I want to plot how the position of all of the individual rats which were captured more than once change over time. I've got a list of the indices of all of the non-repeated elements (i.e. all the rats which were seen once, but not again), but don't know where to go from there.
Kshitij Singh answered .
2025-11-20
A = 1040x3 array [r,c] = size(A); [tags, iA,ic] = unique(A(:,1)); % rats that have been captured t = 1:r; % scale time as needed. rat2 = setdiff(tags,iA); % rats that have been captured more than once colr = ['b','g','r','m','c','k']; % identify rats with different colors figure; for i=1:length(rat2) ind = A(:,1)==A(rat2(i),1); % pick all the rat locs for rat i plot3(t(ind),A(ind,2),A(ind,3),colr(i)); % plot rat i trajectory hold on; end grid on;