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  11 .TH fdim 3M "12 Jul 2006" "SunOS 5.11" "Mathematical Library Functions"
  12 .SH NAME
  13 fdim, fdimf, fdiml \- compute positive difference between two floating-point
  14 numbers
  15 .SH SYNOPSIS
  16 .LP
  17 .nf
  18 c99 [ \fIflag\fR... ] \fIfile\fR... \fB-lm\fR [ \fIlibrary\fR... ]
  19 #include <math.h>
  20 
  21 \fBdouble\fR \fBfdim\fR(\fBdouble\fR \fIx\fR, \fBdouble\fR \fIy\fR);
  22 .fi
  23 
  24 .LP
  25 .nf
  26 \fBfloat\fR \fBfdimf\fR(\fBfloat\fR \fIx\fR, \fBfloat\fR \fIy\fR);
  27 .fi
  28 
  29 .LP
  30 .nf
  31 \fBlong double\fR \fBfdiml\fR(\fBlong double\fR \fIx\fR, \fBlong double\fR \fIy\fR);
  32 .fi
  33 
  34 .SH DESCRIPTION
  35 .sp
  36 .LP
  37 These functions determine the positive difference between their arguments. If
  38 \fIx\fR is greater than \fIy\fR, \fIx\fR\(mi\fIy\fR is returned. If \fIx\fR is
  39 less than or equal to \fIy\fR, +0 is returned.
  40 .SH RETURN VALUES
  41 .sp
  42 .LP
  43 Upon successful completion, these functions return the positive difference
  44 value.
  45 .sp
  46 .LP
  47 If \fIx\fR\(mi\fIy\fR is positive and overflows, a range error occurs and
  48 \fBfdim()\fR, \fBfdimf()\fR, and \fBfdiml()\fR returns the value of the macro
  49 \fBHUGE_VAL\fR, \fBHUGE_VALF\fR, and \fBHUGE_VALL\fR, respectively.
  50 .sp
  51 .LP
  52 If \fIx\fR or \fIy\fR is NaN, a NaN is returned.
  53 .SH ERRORS
  54 .sp
  55 .LP
  56 These functions will fail if:
  57 .sp
  58 .ne 2
  59 .mk
  60 .na
  61 \fBRange Error\fR
  62 .ad
  63 .RS 15n
  64 .rt  
  65 The result overflows.
  66 .sp
  67 If the integer expression (\fBmath_errhandling\fR & \fBMATH_ERREXCEPT\fR) is
  68 non-zero, the overflow floating-point exception will be raised.
  69 .RE
  70 
  71 .SH USAGE
  72 .sp
  73 .LP
  74 An application wanting to check for exceptions should call
  75 \fBfeclearexcept\fR(\fBFE_ALL_EXCEPT\fR) before calling these functions. On
  76 return, if \fBfetestexcept\fR(\fBFE_INVALID\fR | \fBFE_DIVBYZERO\fR |
  77 \fBFE_OVERFLOW\fR | \fBFE_UNDERFLOW\fR) is non-zero, an exception has been
  78 raised. An application should either examine the return value or check the
  79 floating point exception flags to detect exceptions.
  80 .SH ATTRIBUTES
  81 .sp
  82 .LP
  83 See \fBattributes\fR(5) for descriptions of the following attributes:
  84 .sp
  85 
  86 .sp
  87 .TS
  88 tab() box;
  89 cw(2.75i) |cw(2.75i) 
  90 lw(2.75i) |lw(2.75i) 
  91 .
  92 ATTRIBUTE TYPEATTRIBUTE VALUE
  93 _
  94 Interface StabilityStandard
  95 _
  96 MT-LevelMT-Safe
  97 .TE
  98 
  99 .SH SEE ALSO
 100 .sp
 101 .LP
 102 \fBfeclearexcept\fR(3M), \fBfetestexcept\fR(3M), \fBfmax\fR(3M),
 103 \fBfmin\fR(3M), \fBmath.h\fR(3HEAD), \fBattributes\fR(5), \fBstandards\fR(5)