topic Re: array for sumproduct across variables in SAS Programming

array for sumproduct across variables

nash_sas — Thu, 13 Feb 2014 21:26:41 GMT

Need help to finish the below code to get sumproduct with arrays. Thanks

data test;

array xvals{1:1000} _TEMPORARY_;

array yvals{1:1000} _TEMPORARY_;

do i=1 to 1000;

sumproduct=sum(of xvals(i)*yvals(i)); /* I am stuck here ???*/

end;

run;

Re: array for sumproduct across variables

Reeza — Thu, 13 Feb 2014 21:48:57 GMT

You're not retaining anything between loop iterations, so the value you're getting, summing it doesn't error out, is the last summation.

This assumes that you want the sum of xvals(i)*yvals(i) and not something else.

data test;

array xvals{1:1000} _TEMPORARY_;

array yvals{1:1000} _TEMPORARY_;

sumproduct=0;

do i=1 to 1000;

sumproduct=sumproduct+xvals(i)*yvals(i); /* I am stuck here ???*/

end;

run;

Re: array for sumproduct across variables

nash_sas — Thu, 13 Feb 2014 21:59:25 GMT

Thanks Reeza. I tried that but still end result of sumproduct didn't give the expected result. started with 3 values, instead of 1000 and expected result for sumproduct is 14 = (1*1) + (2*2) + (3*3 ) which isn't coming with this code

data test;

array xvals{1:3} _TEMPORARY_;

array yvals{1:3} _TEMPORARY_;

sumproduct=0;

do i=1 to 3;

sumproduct=sumproduct+xvals(i)*yvals(i);

end;

run;

Re: array for sumproduct across variables

Reeza — Thu, 13 Feb 2014 22:01:14 GMT

Where do you put the values in the array?

Re: array for sumproduct across variables

data_null__ — Thu, 13 Feb 2014 22:02:13 GMT

You need to give XVALS and YVALS some values.

Re: array for sumproduct across variables

Reeza — Thu, 13 Feb 2014 22:53:38 GMT

data test;

array xvals{1:3} _TEMPORARY_ (1:3);

array yvals{1:3} _TEMPORARY_ (1:3);

sumproduct=0;

do i=1 to dim(xvals);

sumproduct=sumproduct+xvals(i)*yvals(i);

end;

run;

Re: array for sumproduct across variables

nash_sas — Thu, 13 Feb 2014 23:47:12 GMT

Thanks Reeza. Finally I came up with the below solution to have sum product for all 1000 values (variables in case of my dataset). This is same as excel sumproduct with few lines of SAS code. Kudos !!!

%macro vals;

%do i = 1 %to 1000;

%end;

%mend;

data test;

array xvals{1000} _TEMPORARY_ (%vals);

array yvals{1000} _TEMPORARY_ (%vals);

sumproduct = 0;

do i=1 to 1000;

sumproduct= sum(sumproduct, (xvals(i)*yvals(i)));

end;

run;

Re: array for sumproduct across variables

data_null__ — Thu, 13 Feb 2014 23:52:36 GMT

What is the purpose of the ARRAYS? You are summing i*i.