Calculation Error

[teja04]

Hi All, I have two numeric variables A & B, each variable length is 8. For example, two variables have same values. When I was subtracting
2985014.3137841 - 2885014.3137841
I am getting the value -4.65661E-10. Does anyone
have any ideaa why it is showing such value instead of '0'.

[novinosrin]

data diff;
a=2985014.3137841 ;
b=2985014.3137841;
dif=a-b;
run;

proc print noobs;run;

SAS Output

The SAS System

a	b	dif
2985014.31	2985014.31	0

[PGStats]

The two number are not equal, they are just displayed as equal. A -4E-10 difference is not visible when you display only 7 decimals. See @novinosrin's demonstration above.

[teja04]

Thank you novinosrin and PGStats. I have tried this.. but the problem was other values have different decimals. Maximum decimals I am having is 8. I am not supposed to use ROUND function.

[PGStats]

Why do you expect the difference to be zero?

[Kurt_Bremser]

---

@teja04 wrote:
I am not supposed to use ROUND function.

---

Don't be an idiot. The tool for removing such artifacts of SAS numerical precision issues is the round() function, so use it. See Maxim 14.

[Reeza]

https://documentation.sas.com/?docsetId=lrcon&docsetTarget=p0ji1unv6thm0dn1gp4t01a1u0g6.htm&docsetVe...

[teja04]

Okay.. I got your point. Can't we display the numeric value other than -4E-10 value.

[Reeza]

Sure, just format it and it will look like a zero.

format diff 8.2;