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Diffstat (limited to 'libm/float/dawsnf.c')
-rw-r--r-- | libm/float/dawsnf.c | 168 |
1 files changed, 0 insertions, 168 deletions
diff --git a/libm/float/dawsnf.c b/libm/float/dawsnf.c deleted file mode 100644 index d00607719..000000000 --- a/libm/float/dawsnf.c +++ /dev/null @@ -1,168 +0,0 @@ -/* dawsnf.c - * - * Dawson's Integral - * - * - * - * SYNOPSIS: - * - * float x, y, dawsnf(); - * - * y = dawsnf( x ); - * - * - * - * DESCRIPTION: - * - * Approximates the integral - * - * x - * - - * 2 | | 2 - * dawsn(x) = exp( -x ) | exp( t ) dt - * | | - * - - * 0 - * - * Three different rational approximations are employed, for - * the intervals 0 to 3.25; 3.25 to 6.25; and 6.25 up. - * - * - * ACCURACY: - * - * Relative error: - * arithmetic domain # trials peak rms - * IEEE 0,10 50000 4.4e-7 6.3e-8 - * - * - */ - -/* dawsn.c */ - - -/* -Cephes Math Library Release 2.1: January, 1989 -Copyright 1984, 1987, 1989 by Stephen L. Moshier -Direct inquiries to 30 Frost Street, Cambridge, MA 02140 -*/ - -#include <math.h> -/* Dawson's integral, interval 0 to 3.25 */ -static float AN[10] = { - 1.13681498971755972054E-11, - 8.49262267667473811108E-10, - 1.94434204175553054283E-8, - 9.53151741254484363489E-7, - 3.07828309874913200438E-6, - 3.52513368520288738649E-4, --8.50149846724410912031E-4, - 4.22618223005546594270E-2, --9.17480371773452345351E-2, - 9.99999999999999994612E-1, -}; -static float AD[11] = { - 2.40372073066762605484E-11, - 1.48864681368493396752E-9, - 5.21265281010541664570E-8, - 1.27258478273186970203E-6, - 2.32490249820789513991E-5, - 3.25524741826057911661E-4, - 3.48805814657162590916E-3, - 2.79448531198828973716E-2, - 1.58874241960120565368E-1, - 5.74918629489320327824E-1, - 1.00000000000000000539E0, -}; - -/* interval 3.25 to 6.25 */ -static float BN[11] = { - 5.08955156417900903354E-1, --2.44754418142697847934E-1, - 9.41512335303534411857E-2, --2.18711255142039025206E-2, - 3.66207612329569181322E-3, --4.23209114460388756528E-4, - 3.59641304793896631888E-5, --2.14640351719968974225E-6, - 9.10010780076391431042E-8, --2.40274520828250956942E-9, - 3.59233385440928410398E-11, -}; -static float BD[10] = { -/* 1.00000000000000000000E0,*/ --6.31839869873368190192E-1, - 2.36706788228248691528E-1, --5.31806367003223277662E-2, - 8.48041718586295374409E-3, --9.47996768486665330168E-4, - 7.81025592944552338085E-5, --4.55875153252442634831E-6, - 1.89100358111421846170E-7, --4.91324691331920606875E-9, - 7.18466403235734541950E-11, -}; - -/* 6.25 to infinity */ -static float CN[5] = { --5.90592860534773254987E-1, - 6.29235242724368800674E-1, --1.72858975380388136411E-1, - 1.64837047825189632310E-2, --4.86827613020462700845E-4, -}; -static float CD[5] = { -/* 1.00000000000000000000E0,*/ --2.69820057197544900361E0, - 1.73270799045947845857E0, --3.93708582281939493482E-1, - 3.44278924041233391079E-2, --9.73655226040941223894E-4, -}; - - -extern float PIF, MACHEPF; -#define fabsf(x) ( (x) < 0 ? -(x) : (x) ) -#ifdef ANSIC -float polevlf(float, float *, int); -float p1evlf(float, float *, int); -#else -float polevlf(), p1evlf(); -#endif - -float dawsnf( float xxx ) -{ -float xx, x, y; -int sign; - -xx = xxx; -sign = 1; -if( xx < 0.0 ) - { - sign = -1; - xx = -xx; - } - -if( xx < 3.25 ) - { - x = xx*xx; - y = xx * polevlf( x, AN, 9 )/polevlf( x, AD, 10 ); - return( sign * y ); - } - - -x = 1.0/(xx*xx); - -if( xx < 6.25 ) - { - y = 1.0/xx + x * polevlf( x, BN, 10) / (p1evlf( x, BD, 10) * xx); - return( sign * 0.5 * y ); - } - - -if( xx > 1.0e9 ) - return( (sign * 0.5)/xx ); - -/* 6.25 to infinity */ -y = 1.0/xx + x * polevlf( x, CN, 4) / (p1evlf( x, CD, 5) * xx); -return( sign * 0.5 * y ); -} |