Subtracting pairs of adjacent columns in an array without overlap

I am relatively new to Matlab and I am trying to get the difference between adjacent columns from an array where the columns alternate by condition (i.e., a contrast between experimental and control conditions). I have found code that on the surface seems to be what I am looking for (e.g., https://www.mathworks.com/matlabcentral/answers/743387-how-to-substract-every-two-adjacent-column-from-a-matrix?s_tid=srchtitle&s_tid=mwa_osa_a) but it actually calculates the difference for columns 1-2, 2-3, 3-4 , etc. but I want 1-2, 3-4, 5-6, etc. without any overlap.

e.g., a [72, 324]

b = a(:1:end-1) - a(:,2:end)

I am trying to get an output array with half the number of original columns (i.e., [72, 162])

Answer 1

[Steven Lord]

x = (1:10).^2

x = 1×10

1 4 9 16 25 36 49 64 81 100

y = x(:, 1:2:end)-x(:, 2:2:end)

y = 1×5

-3 -7 -11 -15 -19

[Lisa Bunker]

Thank you!