topic Re: Cumulative Sum in Intel® Integrated Performance Primitives

Cumulative Sum

thorsan1 — Fri, 02 Jun 2006 16:26:49 GMT

Hi

I need to compute the cumulative sum of a 1D signal. In C it would look like

for(int k=0;k...)
{
A += A[k-1];
}

How can this be done using intrinsics and/or IPP?

Thanks for any help

Re: Cumulative Sum

Vladimir_Dudnik — Fri, 02 Jun 2006 17:08:32 GMT

Hello,

As I remember there was a similar question regarding 2D operation, you can see thread

http://softwareforums.intel.com/ids/board/message?board.id=IPP&message.id=980

regarding piece of code you shown, is it exactly what you mean? This code will read data from outside of available memory for k=0.

We do not have similar functions in IPP. You can take a look on ippsSum function family, which calculate sum of all elements in 1D vector

Regards,
Vladimir

Re: Cumulative Sum

Intel_C_Intel — Fri, 02 Jun 2006 18:18:27 GMT

Hi!

IPP has function ippiIntegral that calculates the image integral on the rectangular area. If you call it for the image with 1 row you get the cumulative sum

Alexander

Re: Cumulative Sum

thorsan1 — Sun, 04 Jun 2006 16:57:44 GMT

hi

thanks for the help.

ok. there was an error in the kode the loop should go from k=1...

Ill take a look at the integral function. but does anyone know how it is done?

thorsan

Re: Cumulative Sum

Intel_C_Intel — Tue, 06 Jun 2006 17:49:30 GMT

Imageintegral function maps input NxM image to output (N+1)x(M+1) image. It calculates dst[n,m]=SUM(src[i,j]), i

For more details see IPP Manual Image processing

Alexander