log function
Richard A. O'Keefe
ok at goanna.cs.rmit.oz.au
Fri Jun 21 22:14:50 AEST 1991
In article <1991Jun21.113211 at cs.utwente.nl>, stadt at cs.utwente.nl (Richard van de Stadt) writes:
> I get the error message
> log: SING error
from
> store_control_parameter (mean / log (1/get_acceptance_ratio_X0()))
> Does anybody know what the error message means?
If you R the FM (it looks as though you're using System V, so the FM in
question is 'man 3 exp' or 'man 3 matherr', I looked up the SVID v1) it
tells you that SING from log() or log10() means that the argument is
not positive.
> The same message appears when I split up the statement:
> tolog = 1/get_acceptance_ratio_X0(); /* tolog has then value 1.25 */
> loggie = log (tolog); /* now this is the statement that causes the message */
This is very strange. Have you tried writing a program that just evaluates
log(1.25) and seeing what it does?
By the way, I note that log(1/x) = -log(x), so
store_control_parameter(-mean/log(get_acceptance_ratio_X0()));
should compute the same thing. Does it fail the same way?
What does the declaration of log() in your <math.h> look like?
Does lint tell you anything interesting?
--
I agree with Jim Giles about many of the deficiencies of present UNIX.
More information about the Comp.lang.c
mailing list