Question

I have a ~ 100000/2 matrix. I’d like to go down the columns, average each vertically adjacent value, and insert that value in between the two values. For example…

1  2
3  4
4  6
7  8

would become

1   2
2   3
3   4
3.5 5
4   6
5.5 7
7   8

I’m not sure if there is a terse way to do this in matlab. I took a look at http://www.mathworks.com/matlabcentral/fileexchange/9984 but it seems to insert all of the rows in a matrix into the other one at a specific point. Obviously it can still be used, but just wondering if there is a simpler way.

Any help is appreciated, thanks.

Answer 1

Untested:

% Take the mean of adjacent pairs
x_mean = ([x; 0 0] + [0 0; x]) / 2;
% Interleave the two matrices
y = kron(x, [1;0]) + kron(x_mean(1:end-1,:), [0;1]);