Method to compound daily data by n-days?

Given:

[1 2 3 4 5 6] and n = 1,

return [1, 2, 3, 4, 5, 6]

given n=2, return: [1*2, 3*4, 5*6]

given n=3, return: [1*2*3, 4*5*6]

given n=4, return [1*2*3*4]

given n=5, return [1*2*3*4*5]

given n=6, return [1*2*3*4*5*6]

not sure what to call this algorithm, but can anyone think of a clever way to do it?

Answer 1

[Yi Sui]

function re = foo(x,n)

len = length(x);

seg = floor(len/n);

res = mod(len,n);

x2 = mat2cell(x,1,[ones(1,seg).*n res]);

re = cellfun(@prod,x2);

re = re(1:end-1);

Answer 2

[Andrei Bobrov]

I = 1:6; % The initial array
out = nonzeros(prod(reshape([I,zeros(1,mod(-numel(I),n))],n,[])))';