Re: Quick question on math in C

Actually I take that back, abs is in stdlib (for some reason...)
so you'll have to #include <stdlib.h>, no extra linking required.

On 4/16/05, Michael Barton <[email protected]> wrote:
> Or:
>   variable = -variable;
> takes less cpu than multiplying by -1.
> 
> If you use abs, you'll also have to add -lm to the L_FLAGS in your
> makefile (to link to the math library).
> Or you could just write your own...
>   int my_abs(int a)
>   {
>     return (a < 0) ? -a : a;
>   }
> 
> On 4/16/05, Ammaross Danan <[email protected]> wrote:
> > Number * -1
> >
> > Or
> >
> > #include <math.h>
> > Number = abs(Number);
> >
> > Use the later if you always want it to be positive, the first could
> > potentially make it go negative if it was positive to begin with...
> >
> > Ammaross
> > www.rotf.net
> >
> > -----Original Message-----
> > From: [email protected] [mailto:[email protected]] On Behalf Of cyhawk
> > Sent: Saturday, April 16, 2005 1:54 PM
> > To: [email protected]
> > Subject: Quick question on math in C
> >
> > Err how would i convert a negitive number to a positive number?
> > ie -5 to 5
> > or -754 to 754
> > in c?
> >
> > Google was no help cause i have no idea how to form the question ;) Thanks
> > =)
> > --
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> 
> On 4/16/05, Ammaross Danan <[email protected]> wrote:
> > Number * -1
> >
> > Or
> >
> > #include <math.h>
> > Number = abs(Number);
> >
> > Use the later if you always want it to be positive, the first could
> > potentially make it go negative if it was positive to begin with...
> >
> > Ammaross
> > www.rotf.net
> >
> > -----Original Message-----
> > From: [email protected] [mailto:[email protected]] On Behalf Of cyhawk
> > Sent: Saturday, April 16, 2005 1:54 PM
> > To: [email protected]
> > Subject: Quick question on math in C
> >
> > Err how would i convert a negitive number to a positive number?
> > ie -5 to 5
> > or -754 to 754
> > in c?
> >
> > Google was no help cause i have no idea how to form the question ;) Thanks
> > =)
> > --
> > ROM mailing list
> > [email protected]
> > Unsubscribe here ->>> http://www.rom.org/cgi-bin/mailman/listinfo/rom
> >
> > --
> > ROM mailing list
> > [email protected]
> > Unsubscribe here ->>> http://www.rom.org/cgi-bin/mailman/listinfo/rom
> >
>
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