Eval(R) - the R does NOT mean round...

["William A.\(Tony\) Corbett" <corbett@xxxxxxxxxxxxxxx>]

Hi all,
This just bit me today and I thought I'd share it.  I've always assumed that
the extender (R) on the Eval statement meant Round the result.  Don't know
why I thought that, I guess I just jumped to a logical conclusion.

My problem today was:
Eval(R) wkdsc1 = (tmdisc * odmtot)
         8.34  =   .020  * 417.30
Real answer is 8.346, from a calculator
wkdsc1 should be 8.35

Eval(H)   wkdsc1 = (tmdisc * odmtot)
this one gets 8.35, as expected above........

>From the RPG reference:
----------------------------------------------------
There are two sets of precision rules that you can use to control the sizes
of intermediate values:

The default rules give you intermediate results that are as large as
possible in order to
minimize the possibility of numeric overflow. Unfortunately, in certain
cases, this may yield results with zero decimal places if the result is very
large.

The "Result Decimal Positions" precision rule works the same as the default
rule except that if the statement involves an assignment to a numeric
variable or a conversion to a specific decimal precision, the number of
decimal positions of any intermediate result is never reduced below the
desired result decimal places.
----------------------------------------------------
This is on a V4R4 machine, at first I thought it was a compiler error which
hopefully is fixed on a subsequent release.  To me, this makes the (R)
extender less than worthless and I cannot imagine who on the Rochester
development team thought this was a good idea, since the Eval with no
extender (default rules) should give this same result except with more
accurate intermediate work variables used.

Or is it just me????  Maybe I'll feel better about this when the blood on my
head dries (from beating my head against the wall trying to figure out what
the problem was).

AS/Resources, Inc.
William A.(Tony) Corbett
IBM Certified Specialist - AS/400 Developer
http://www.asresources.com
corbett@asresources.com
770-587-4812 (office)
678-935-5006 (mobile)
404-663-4737 (fax)