topic Re: Automatic Rounding in SAS Programming

Automatic Rounding

angeliquec — Sat, 25 Jun 2016 00:19:35 GMT

Hi,

In the code below, the SAS base application in our office displays the values in 'displayed' column when a is divided by b, then multiplied to 100, even if we made the format best32. However, the calculator gives longer values.

But when I tried doing the division in the "want" dataset in SAS Studio (SAS base on demand), the division works fine.

Can the automatic rounding of SAS be fixed?

data have;
input a b displayed;
cards;
16854.17 197890.028 8.5169375
819368.85 369280 221.8828125
150914.35 255027.6243 59.1756875
226253.24 858790.6977 26.3455625
100876.91 363464.5669 27.7542625
14788.51 777104.3771 1.9030275
;
run;

data want;
set have;
d = (a/b)*100;
run;

Re: Automatic Rounding

Reeza — Sat, 25 Jun 2016 00:48:16 GMT

Can you post the numbers you want to see?

What version of SAS are you working on?

Most likely it's related to numerical precision:

http://support.sas.com/documentation/cdl/en/lrcon/68089/HTML/default/viewer.htm#p0ji1unv6thm0dn1gp4t01a1u0g6.htm

Re: Automatic Rounding

angeliquec — Sat, 25 Jun 2016 02:21:34 GMT

Hi Reeza,

We're using 9.4. The numbers I want are those under column d in the want dataset, which have more precision

Re: Automatic Rounding

PGStats — Sat, 25 Jun 2016 02:56:01 GMT

Try


proc print data=want;
format d 20.10;
run;

Re: Automatic Rounding

angeliquec — Mon, 27 Jun 2016 01:07:40 GMT

Hi Reeza

Apologies, we are using SAS 9.0.
Is there a way to address this precision issue?

Re: Automatic Rounding

Reeza — Mon, 27 Jun 2016 01:34:20 GMT

I doubt you're using 9.0...that would be akin to using Windows XP version 1, not even SP4.

What do you get from:

%put &sysver;

Re: Automatic Rounding

angeliquec — Mon, 27 Jun 2016 04:38:17 GMT

sorry, 9.4.

For the first row in the have data, SAS gives a quotient of 8.516937500000 when the actual answer is 8.5163749995668. SAS seems to do truncation there.

Re: Automatic Rounding

andreas_lds — Mon, 27 Jun 2016 09:51:08 GMT

Interesting, win7 calculator returns 8.5169374982351308778429199070102 for the first row.

With format 20.10 applyed to variable d, SAS returns 8.5169374982 - SAS on Windows and Linux uses up to 15 digits. I don't think that value can be increased by altering a config file or by setting a sas system option.