vectors that arent scalar

IM = [expt.IM];
memorability = [expt.memorability];
 
[~, idx] = sort(IM);
IM = IM(idx);
memorability = memorability(idx);
plot(IM, memorability)

this is my code, but IM is not scalar so my graph looks wonky, its putting

in my 1x960 array IM means Image

each IM 1-960 has a random number as the jpeg name. So the first IM is 588 (but this number means nothing!!!) how I can just either rename them to 1-960 or just keep the order what it is not by these names

[Walter Roberson]

I answered this at https://www.mathworks.com/matlabcentral/answers/491202-how-to-get-struct-array-field-as-a-vector-and-compare-the-two-fields#comment_767505 before you posted this question.