Date: Jan 28, 2013 6:53 AM
Author: Barry Shaw
Subject: Re: Cumulative sum

for i = 1 : 5
if issorted(flipud(hewson([1:2],i))) %assumes that you only care about top 2 elements
hewson(:,end+1) = cumsum(hewson(:,i),1)
end
end

hewson =

1 5 8 4 7 8
3 6 4 7 9 12
3 6 7 9 5 19
2 5 6 7 5 25

Barry

"sam" wrote in message <ke5kpo$gjt$1@newscl01ah.mathworks.com>...
> I am new to Matlab and trying to create a a fairly simple matrix. one of my columns i want to be the cumualtive sum of another column. For example the below matrix, i want the next column (6) to be the cumulative sum of column 3 as it decends. so the first number will be 8 then the second number will be (8+4) 12 then the third will be (8+4+7) 19 and so on.
>
> 1 5 8 4 7
> 3 6 4 7 9
> 3 6 7 9 5
> 2 5 6 7 5
>
> i havetried various ways such as the one below but with no success, can anyone please tell me where i am going wrong?
> hewson is the name of my matrices
>
> for r = 1:20
> for c=6
> hewson (r,c) = cumsum(r,3);
> end
> end
>
> Many Thanks
> sam