How can I sum each 3 columns array?

Hi, i want to sum each 3 columns of my array for any array dimension.

For example, Y array is the sum of each X array respectively to its color.

Need this to do sum for Nx150 array, so that it can turn into Nx50 array

Thanks!

Answer 1

[David Hill]

m=movsum(x,3);
y=m(:,1:3:end);

[ang bn]

I'm sorry, is "movesum" a new function? because i couldnt find it in my matlab (r2015a)

thanks

Edit:

I just knew we can do matlab online, and it works perfectly, thank you so much!

[Walter Roberson]

movsum is R2016a and newer

[ang bn]

okay now I'll just do matlab online, maybe later I will install newer version

thanks!

Answer 2

[Walter Roberson]

reshape(x, size(x,1), 3, [])

now you can sum along the second dimension, and then reshape to remove the now-singular second dimension.