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.TH FDIM 3M "Jul 12, 2006" "SunOS 5.11" "Mathematical Library Functions"
.SH NAME
fdim, fdimf, fdiml \- compute positive difference between two floating-point
numbers
.SH SYNOPSIS
.LP
.nf
c99 [ \fIflag\fR... ] \fIfile\fR... \fB-lm\fR [ \fIlibrary\fR... ]
#include <math.h>

\fBdouble\fR \fBfdim\fR(\fBdouble\fR \fIx\fR, \fBdouble\fR \fIy\fR);
.fi

.LP
.nf
\fBfloat\fR \fBfdimf\fR(\fBfloat\fR \fIx\fR, \fBfloat\fR \fIy\fR);
.fi

.LP
.nf
\fBlong double\fR \fBfdiml\fR(\fBlong double\fR \fIx\fR, \fBlong double\fR \fIy\fR);
.fi

.SH DESCRIPTION
.sp
.LP
These functions determine the positive difference between their arguments. If
\fIx\fR is greater than \fIy\fR, \fIx\fR\(mi\fIy\fR is returned. If \fIx\fR is
less than or equal to \fIy\fR, +0 is returned.
.SH RETURN VALUES
.sp
.LP
Upon successful completion, these functions return the positive difference
value.
.sp
.LP
If \fIx\fR\(mi\fIy\fR is positive and overflows, a range error occurs and
\fBfdim()\fR, \fBfdimf()\fR, and \fBfdiml()\fR returns the value of the macro
\fBHUGE_VAL\fR, \fBHUGE_VALF\fR, and \fBHUGE_VALL\fR, respectively.
.sp
.LP
If \fIx\fR or \fIy\fR is NaN, a NaN is returned.
.SH ERRORS
.sp
.LP
These functions will fail if:
.sp
.ne 2
.mk
.na
\fBRange Error\fR
.ad
.RS 15n
.rt
The result overflows.
.sp
If the integer expression (\fBmath_errhandling\fR & \fBMATH_ERREXCEPT\fR) is
non-zero, the overflow floating-point exception will be raised.
.RE

.SH USAGE
.sp
.LP
An application wanting to check for exceptions should call
\fBfeclearexcept\fR(\fBFE_ALL_EXCEPT\fR) before calling these functions. On
return, if \fBfetestexcept\fR(\fBFE_INVALID\fR | \fBFE_DIVBYZERO\fR |
\fBFE_OVERFLOW\fR | \fBFE_UNDERFLOW\fR) is non-zero, an exception has been
raised. An application should either examine the return value or check the
floating point exception flags to detect exceptions.
.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(7) for descriptions of the following attributes:
.sp

.sp
.TS
tab(	) box;
cw(2.75i) |cw(2.75i)
lw(2.75i) |lw(2.75i)
.
ATTRIBUTE TYPE	ATTRIBUTE VALUE
_
Interface Stability	Standard
_
MT-Level	MT-Safe
.TE

.SH SEE ALSO
.sp
.LP
.BR math.h (3HEAD),
.BR feclearexcept (3M),
.BR fetestexcept (3M),
.BR fmax (3M),
.BR fmin (3M),
.BR attributes (7),
.BR standards (7)