topic Re: Rename columns and array operation using a loop in SAS Enterprise Guide

Rename columns and array operation using a loop

ayin — Wed, 15 Mar 2017 02:38:58 GMT

/* data have */
Class Time_0 Time_1 Time_2
  A      1     2      4
  B      0     3      9
  C      3     6      0

/* data want */
Class _01 _12
  A    2    2
  B    1    3
  C    2    0

Rule 1: In data 'want', column '_01' = column 'Time_1' / 'Time_0' from data 'have'.

'_12' = 'Time_2' / 'Time_1'.

....

Rule 2: If divisor = 0 then result = 1.

Because my actual data have more than 100 'time' columns: Time_0-Time_&Num (Num is a global macro variable), would prefer using a loop rather than hardcode it.

Thanks.

Re: Rename columns and array operation using a loop

Astounding — Wed, 15 Mar 2017 03:13:43 GMT

The naming of the new columns might be a little different here. The name is based on the numerator (but not the denominator):

data want;

set have;

array times {0:&num} time_0 - time_&num;

array ratios {&num} _001 - _&num;

do i=1 to &num;

if times{i-1} = 0 then ratios{i)=0;

else ratios{i} = times{i} / times{i-1};

end;

drop i;

run;

If you would like, you can also drop all the TIME variables as well.

Re: Rename columns and array operation using a loop

RW9 — Wed, 15 Mar 2017 09:14:50 GMT

You are mixing up usage here. Columns names are for identification in the programming, they are not meant to be used as data.