Adding values from columns 1:i for each column for a new matrix of the same size

Hi so I have a 442x25 matrix, what I want to do is for example add values of columns 1 and 2 together to create a new column 2, add values of columns 1, 2 and 3 to create a new column 3, add values of columns 1, 2, 3 and 4 to create a new column 4 and so on until column 25 where all the values will be added. If that makes sense to anyone i would really appreciate your help!

[Stephen23]

https://www.mathworks.com/help/matlab/ref/cumsum.html

Answer 1

[Andrei Bobrov]

Let A - your array (442 x 25)

out = cumsum(A,2);

Answer 2

[Stijn Haenen]

Something like this?

matrix=[1 2 3; 1 2 3; 1 2 3; 1 2 3];
for i=1:size(matrix,2)
    matrix_new(:,i)=sum(matrix(:,1:i),2);
end