Delete numbers that are not in both arrays

I have four arrays. I want to delete all the numbers that are not in all of the four arrays.

So for example:

A1 = [1 2 3 4 5]

A2 = [2 3 4 6 7]

A3 = [1 2 3 4 6]

A4 = [2 3 4 5 6]

I want to do the following automatically:

A1([1 5]) = [] --> A1 = [2 3 4]

A2([4 5]) = [] --> A2 = [2 3 4]

A3([1 5]) = [] --> A3 = [2 3 4]

A4([4 5]) = [] --> A4 = [2 3 4]

So I want to find the indices to delete the columns that I don't want.

Answer 1

[Steven Lord]

Use the intersect function a couple times. That will be easier if you define an array or a cell array of data rather than using numbered variable names.