| paul@2 | 1 | |
| paul@2 | 2 | /* @(#)w_hypot.c 5.1 93/09/24 */ |
| paul@2 | 3 | /* |
| paul@2 | 4 | * ==================================================== |
| paul@2 | 5 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
| paul@2 | 6 | * |
| paul@2 | 7 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
| paul@2 | 8 | * Permission to use, copy, modify, and distribute this |
| paul@2 | 9 | * software is freely granted, provided that this notice |
| paul@2 | 10 | * is preserved. |
| paul@2 | 11 | * ==================================================== |
| paul@2 | 12 | */ |
| paul@2 | 13 | |
| paul@2 | 14 | /* |
| paul@2 | 15 | FUNCTION |
| paul@2 | 16 | <<hypot>>, <<hypotf>>---distance from origin |
| paul@2 | 17 | INDEX |
| paul@2 | 18 | hypot |
| paul@2 | 19 | INDEX |
| paul@2 | 20 | hypotf |
| paul@2 | 21 | |
| paul@2 | 22 | SYNOPSIS |
| paul@2 | 23 | #include <math.h> |
| paul@2 | 24 | double hypot(double <[x]>, double <[y]>); |
| paul@2 | 25 | float hypotf(float <[x]>, float <[y]>); |
| paul@2 | 26 | |
| paul@2 | 27 | DESCRIPTION |
| paul@2 | 28 | <<hypot>> calculates the Euclidean distance |
| paul@2 | 29 | @tex |
| paul@2 | 30 | $\sqrt{x^2+y^2}$ |
| paul@2 | 31 | @end tex |
| paul@2 | 32 | @ifnottex |
| paul@2 | 33 | <<sqrt(<[x]>*<[x]> + <[y]>*<[y]>)>> |
| paul@2 | 34 | @end ifnottex |
| paul@2 | 35 | between the origin (0,0) and a point represented by the |
| paul@2 | 36 | Cartesian coordinates (<[x]>,<[y]>). <<hypotf>> differs only |
| paul@2 | 37 | in the type of its arguments and result. |
| paul@2 | 38 | |
| paul@2 | 39 | RETURNS |
| paul@2 | 40 | Normally, the distance value is returned. On overflow, |
| paul@2 | 41 | <<hypot>> returns <<HUGE_VAL>> and sets <<errno>> to |
| paul@2 | 42 | <<ERANGE>>. |
| paul@2 | 43 | |
| paul@2 | 44 | PORTABILITY |
| paul@2 | 45 | <<hypot>> and <<hypotf>> are not ANSI C. */ |
| paul@2 | 46 | |
| paul@2 | 47 | /* |
| paul@2 | 48 | * wrapper hypot(x,y) |
| paul@2 | 49 | */ |
| paul@2 | 50 | |
| paul@2 | 51 | #include "fdlibm.h" |
| paul@2 | 52 | #include <errno.h> |
| paul@2 | 53 | |
| paul@2 | 54 | #ifndef _DOUBLE_IS_32BITS |
| paul@2 | 55 | |
| paul@2 | 56 | #ifdef __STDC__ |
| paul@2 | 57 | double hypot(double x, double y)/* wrapper hypot */ |
| paul@2 | 58 | #else |
| paul@2 | 59 | double hypot(x,y) /* wrapper hypot */ |
| paul@2 | 60 | double x,y; |
| paul@2 | 61 | #endif |
| paul@2 | 62 | { |
| paul@2 | 63 | #ifdef _IEEE_LIBM |
| paul@2 | 64 | return __ieee754_hypot(x,y); |
| paul@2 | 65 | #else |
| paul@2 | 66 | double z; |
| paul@2 | 67 | z = __ieee754_hypot(x,y); |
| paul@2 | 68 | if(_LIB_VERSION == _IEEE_) return z; |
| paul@2 | 69 | if((!finite(z))&&finite(x)&&finite(y)) { |
| paul@2 | 70 | /* hypot(finite,finite) overflow */ |
| paul@2 | 71 | errno = ERANGE; |
| paul@2 | 72 | return HUGE_VAL; |
| paul@2 | 73 | } else |
| paul@2 | 74 | return z; |
| paul@2 | 75 | #endif |
| paul@2 | 76 | } |
| paul@2 | 77 | |
| paul@2 | 78 | #endif /* defined(_DOUBLE_IS_32BITS) */ |
