fdim(3) - f38

1fdim(3)                    Library Functions Manual                    fdim(3)
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NAME

6       fdim, fdimf, fdiml - positive difference
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LIBRARY

9       Math library (libm, -lm)
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SYNOPSIS

12       #include <math.h>
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14       double fdim(double x, double y);
15       float fdimf(float x, float y);
16       long double fdiml(long double x, long double y);
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18   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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20       fdimf(), fdiml():
21           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
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DESCRIPTION

24       These  functions  return  the  positive difference, max(x-y,0), between
25       their arguments.
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RETURN VALUE

28       On success, these functions return the positive difference.
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30       If x or y is a NaN, a NaN is returned.
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32       If the result overflows, a range error occurs, and the functions return
33       HUGE_VAL, HUGE_VALF, or HUGE_VALL, respectively.
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ERRORS

36       See  math_error(7) for information on how to determine whether an error
37       has occurred when calling these functions.
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39       The following errors can occur:
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41       Range error: result overflow
42              errno is set to ERANGE.  An  overflow  floating-point  exception
43              (FE_OVERFLOW) is raised.
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ATTRIBUTES

46       For  an  explanation  of  the  terms  used  in  this  section,  see at‐
47       tributes(7).
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49       ┌────────────────────────────────────────────┬───────────────┬─────────┐
50       │Interface                                   │ Attribute     │ Value   │
51       ├────────────────────────────────────────────┼───────────────┼─────────┤
52       │fdim(), fdimf(), fdiml()                    │ Thread safety │ MT-Safe │
53       └────────────────────────────────────────────┴───────────────┴─────────┘
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STANDARDS

56       C11, POSIX.1-2008.
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HISTORY

59       glibc 2.1.  C99, POSIX.1-2001.
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BUGS

62       Before glibc 2.24 on certain architectures (e.g., x86, but not  x86_64)
63       these functions did not set errno.
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