The error you get is self explaining, I think. ISM_krock contains many zeros (apparently columns 4 to 6 entirely consist of zeros). An index cannot be a (non-logical) zero. Just a positive integer or a logical.
You should explain better what you want to do. I'm not sure I understand.
If you want to find the index in calendar for one date (e.g. the jth) in ISM_krock , you should compare that date to all those in calendar, using "==". For instance
i = find((calendar(:,1)==ISM_krock(j,1)) & (calendar(:,2)==ISM_krock(j,2)) & (calendar(:,3)==ISM_krock(j,3)));
I'm using just the first 3 columns because I'm not sure of the meaning of all those zeros. I guess the dates are just the firse 3 columns.
If you want to do that for all the dates in ISM_krock, I'm afraid you need to iterate the above comparison over all the rows in ISM_krock. I do not see a way of doing this in a simple "one-liner". But perhaps someone in this forum will prove me wrong.
Another suggestion. It would be more useful to attach the variables themselves (in a *.mat file) instead of their "screenshot".
