topic Re: How to aggregate value in SAS/IML Software and Matrix Computations

How to aggregate value

Crubal — Thu, 16 Mar 2017 19:06:46 GMT

Hi,

I have a dataset called A:

Count | Percent

0 | 0.05

2 | 0.15

5 | 0.20

... .....

How can I obtain a dataset called B, where Cumulative Percentage for Count = 5 is the Percentage for Count <= 5:

(p(Count = 0) + p(Count = 2) + p(Count = 5) = 0.05 + 0.15 + 0.2 = 0.4)

Count | Perenct | Cumulative Percent

0 | 0.05 | 0.05

2 | 0.15 | 0.20

5 | 0.20 | 0.40

... ... ...

Thanks!

Re: How to aggregate value

Rick_SAS — Thu, 16 Mar 2017 19:18:37 GMT

Use the CUSUM function:

proc iml;
percent = {0.05, 0.15, 0.2, 0.4, 0.2};
cusum = cusum(percent);
print percent cusum;

Re: How to aggregate value

Reeza — Thu, 16 Mar 2017 19:18:58 GMT

Are you using IML?

My assumption is you're looking to calculate the cumulative value?

If so, something as simple as:

retain cum_percent;
cum_percent = sum(cum_percent,  percent);

Re: How to aggregate value

Crubal — Thu, 16 Mar 2017 19:25:49 GMT

Hi,

Any kind of procedure if works would be great! And I just tried yours in a data step, and got what I have. Thanks!

Re: How to aggregate value

Reeza — Thu, 16 Mar 2017 19:29:55 GMT

I'm not sure how you're calculating those numbers in the first place, but if using proc freq/means/tabulate you should be able to calculate the cumulative directly.