hypotl(3)

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

6       hypot, hypotf, hypotl - Euclidean distance function
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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 hypot(double x, double y);
15       float hypotf(float x, float y);
16       long double hypotl(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       hypot():
21           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
22               || _XOPEN_SOURCE
23               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
24               || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
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26       hypotf(), hypotl():
27           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
28               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
29               || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
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DESCRIPTION

32       These  functions  return  sqrt(x*x+y*y).  This is the length of the hy‐
33       potenuse of a right-angled triangle with sides of length x  and  y,  or
34       the distance of the point (x,y) from the origin.
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36       The calculation is performed without undue overflow or underflow during
37       the intermediate steps of the calculation.
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RETURN VALUE

40       On success, these functions return the length of the  hypotenuse  of  a
41       right-angled triangle with sides of length x and y.
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43       If x or y is an infinity, positive infinity is returned.
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45       If x or y is a NaN, and the other argument is not an infinity, a NaN is
46       returned.
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48       If the result overflows, a range error occurs, and the functions return
49       HUGE_VAL, HUGE_VALF, or HUGE_VALL, respectively.
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51       If  both  arguments are subnormal, and the result is subnormal, a range
52       error occurs, and the correct result is returned.
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ERRORS

55       See math_error(7) for information on how to determine whether an  error
56       has occurred when calling these functions.
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58       The following errors can occur:
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60       Range error: result overflow
61              errno  is  set  to ERANGE.  An overflow floating-point exception
62              (FE_OVERFLOW) is raised.
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64       Range error: result underflow
65              An underflow floating-point exception (FE_UNDERFLOW) is raised.
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67              These functions do not set errno for this case.
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ATTRIBUTES

70       For an  explanation  of  the  terms  used  in  this  section,  see  at‐
71       tributes(7).
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73       ┌────────────────────────────────────────────┬───────────────┬─────────┐
74       │Interface                                   │ Attribute     │ Value   │
75       ├────────────────────────────────────────────┼───────────────┼─────────┤
76       │hypot(), hypotf(), hypotl()                 │ Thread safety │ MT-Safe │
77       └────────────────────────────────────────────┴───────────────┴─────────┘
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STANDARDS

80       C11, POSIX.1-2008.
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HISTORY

83       C99, POSIX.1-2001.
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85       The variant returning double also conforms to SVr4, 4.3BSD.
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