topic Re: Help with sub setting output data sets in SAS/IML Software and Matrix Computations

Help with sub setting output data sets

Vovik — Sat, 03 Feb 2018 14:24:14 GMT

Novis, trying to learn IML. In the program below, I am trying to pick the LBN values which satisfies low - high range, create output dataset test1 as subset of test which satisfy this condition in most efficient way (without listing all of the variables).

Thanks.

proc iml ;
use test;

read all var _NUM_ into x[c=NumVar];
close test;

r_x=nrow(x);
c_x=ncol(x);

/* Lab date variable d */
lbn = x[, 'd'];

/*Upper Lower limits for week 100 boundaries*/
low = x[, 'const'] + 2;
high = x[, 'const'] + 15;

outc = x[,'s'];
/* outc = j(nrow(s), 1); */
idx = loc (lbn <= high & lbn >= low );

y=j(nrow());
if ncol (idx)> 0 then y[idx]=x;

print x , y;
print satisfy "Criteria Met";
print (lbn[idx])[label='lab date'] , (low[idx]) [label='lowb'],
(high[idx]) [label='highb'], [label='test'];

create TEST1 from y ;
append from y;
close test1;

quit;

Re: Help with sub setting output data sets

Vovik — Sat, 03 Feb 2018 14:25:38 GMT

Original test data:

data test (drop=v);

p=1; d=2; z=3; const=11; s=0;
output;

do v=1 to 15 by 1;
const=11;
p+3; d+5; z+7;
output;

end;

run;

Re: Help with sub setting output data sets

Rick_SAS — Sat, 03 Feb 2018 16:50:36 GMT

You have read all the variables into X. So use the LOC function to find the rows that satisfy the condition, then use the index to subset the rows of X:

idx = loc (lbn <= high & lbn >= low );
y = x[idx,];   /* subset rows, include all columns */
create TEST1 from y[c=NumVar];
append from y;
close test1;

When you leave the column index blank (as above), it means "use all columns." For more information about subscripting matrices, see "Extracting elements from matrix."

Re: Help with sub setting output data sets

Vovik — Mon, 05 Feb 2018 19:35:33 GMT

Suppose I would like to set values of s to 1 where conditions are met, and leave them as 0 otherwise , and keep all the original observations from test. I tried this, but only was getting 1 value of s =0?

Re: Help with sub setting output data sets

Rick_SAS — Mon, 05 Feb 2018 20:36:09 GMT

z = j(nrow(x), 1, 0);  /* vector with all rows set to 0 */
z[idx] = 1;   /* change these rows to 1 */
x[,'s'] = z;   /* if you want to overwrite original data */