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46 lines
1.1 KiB
46 lines
1.1 KiB
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/* @(#)w_gamma.c 1.3 95/01/18 */ |
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/* |
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* ==================================================== |
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
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* |
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* Developed at SunSoft, a Sun Microsystems, Inc. business. |
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* Permission to use, copy, modify, and distribute this |
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* software is freely granted, provided that this notice |
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* is preserved. |
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* ==================================================== |
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* |
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*/ |
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/* double ieee_gamma(double x) |
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* Return the logarithm of the Gamma function of x. |
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* |
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* Method: call gamma_r |
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*/ |
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#include "fdlibm.h" |
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extern int signgam; |
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#ifdef __STDC__ |
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double ieee_gamma(double x) |
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#else |
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double ieee_gamma(x) |
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double x; |
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#endif |
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{ |
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#ifdef _IEEE_LIBM |
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return __ieee754_gamma_r(x,&signgam); |
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#else |
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double y; |
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y = __ieee754_gamma_r(x,&signgam); |
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if(_LIB_VERSION == _IEEE_) return y; |
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if(!ieee_finite(y)&&ieee_finite(x)) { |
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if(ieee_floor(x)==x&&x<=0.0) |
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return __kernel_standard(x,x,41); /* gamma pole */ |
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else |
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return __kernel_standard(x,x,40); /* gamma overflow */ |
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} else |
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return y; |
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#endif |
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}
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