diff options
author | Christopher Faylor <me@cgf.cx> | 2000-02-17 22:39:52 +0300 |
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committer | Christopher Faylor <me@cgf.cx> | 2000-02-17 22:39:52 +0300 |
commit | 8a0efa53e44919bcf5ccb1d3353618a82afdf8bc (patch) | |
tree | 68c3dbf3f2c6fd5d49777def9914d77b5cd4589d /newlib/libm/mathfp/s_atan2.c | |
parent | 1fd5e000ace55b323124c7e556a7a864b972a5c4 (diff) |
import newlib-2000-02-17 snapshot
Diffstat (limited to 'newlib/libm/mathfp/s_atan2.c')
-rw-r--r-- | newlib/libm/mathfp/s_atan2.c | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/newlib/libm/mathfp/s_atan2.c b/newlib/libm/mathfp/s_atan2.c new file mode 100644 index 000000000..d73a6efc0 --- /dev/null +++ b/newlib/libm/mathfp/s_atan2.c @@ -0,0 +1,89 @@ + +/* @(#)z_atan2.c 1.0 98/08/13 */ + +/* +FUNCTION + <<atan2>>, <<atan2f>>---arc tangent of y/x + +INDEX + atan2 +INDEX + atan2f + +ANSI_SYNOPSIS + #include <math.h> + double atan2(double <[y]>,double <[x]>); + float atan2f(float <[y]>,float <[x]>); + +TRAD_SYNOPSIS + #include <math.h> + double atan2(<[y]>,<[x]>); + double <[y]>; + double <[x]>; + + float atan2f(<[y]>,<[x]>); + float <[y]>; + float <[x]>; + +DESCRIPTION + +<<atan2>> computes the inverse tangent (arc tangent) of <[y]>/<[x]>. +<<atan2>> produces the correct result even for angles near +@ifinfo +pi/2 or -pi/2 +@end ifinfo +@tex +$\pi/2$ or $-\pi/2$ +@end tex +(that is, when <[x]> is near 0). + +<<atan2f>> is identical to <<atan2>>, save that it takes and returns +<<float>>. + +RETURNS +<<atan2>> and <<atan2f>> return a value in radians, in the range of +@ifinfo +-pi to pi. +@end ifinfo +@tex +$-\pi$ to $\pi$. +@end tex + +If both <[x]> and <[y]> are 0.0, <<atan2>> causes a <<DOMAIN>> error. + +You can modify error handling for these functions using <<matherr>>. + +PORTABILITY +<<atan2>> is ANSI C. <<atan2f>> is an extension. + + +*/ + +/****************************************************************** + * Arctangent2 + * + * Input: + * v, u - floating point values + * + * Output: + * arctan2 of v / u + * + * Description: + * This routine returns the arctan2 of v / u. + * + *****************************************************************/ + +#include "fdlibm.h" +#include "zmath.h" + +#ifndef _DOUBLE_IS_32BITS + +double +_DEFUN (atan2, (double, double), + double v _AND + double u) +{ + return (atangent (0.0, v, u, 1)); +} + +#endif /* _DOUBLE_IS_32BITS */ |