MATLAB: How to compare cell arrays of different lengths

Question

clc;clear; a=int64(1:3)'; out=num2cell(a) b = int64(1:4)'; out2 =num2cell(b)

index = out == out2;

index doesn't compute because out and out2 are of different lengths. How to make it work?

Answer 1

We can start with your input

a = int64(1:3)';
out = num2cell(a);
b = int64(1:4)';
out2 =num2cell(b);

We will presume you're looking for something that tells you that "the contents of indexes 1, 2, and 3 match between the two cells", so you're looking for index to return the values 1, 2, and 3.

You have a 3-length and a 4-length cell array. By definition the 4th cell element can't match anything, so we only need to consider up to the smallest array length.

minLen = min(length(out),length(out2));

We can then use cellfun() to compare each pair of elements:

index = find(cellfun(@isequal, out(1:minLen), out2(1:minLen)))

Note that you didn't necessarily need to put integers into cells to do this. Perhaps your real data contains strings or other non-numeric contents, but if you're working with arrays originally you can do the same thing with the raw array contents:

index = find(arrayfun(@isequal, a(1:minLen), b(1:minLen)))

Did this help you out?

Thanks, Sven