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authorEric Andersen <andersen@codepoet.org>2001-11-22 14:04:29 +0000
committerEric Andersen <andersen@codepoet.org>2001-11-22 14:04:29 +0000
commit7ce331c01ce6eb7b3f5c715a38a24359da9c6ee2 (patch)
tree3a7e8476e868ae15f4da1b7ce26b2db6f434468c /libm/float/i1f.c
parentc117dd5fb183afb1a4790a6f6110d88704be6bf8 (diff)
Totally rework the math library, this time based on the MacOs X
math library (which is itself based on the math lib from FreeBSD). -Erik
Diffstat (limited to 'libm/float/i1f.c')
-rw-r--r--libm/float/i1f.c177
1 files changed, 0 insertions, 177 deletions
diff --git a/libm/float/i1f.c b/libm/float/i1f.c
deleted file mode 100644
index e9741e1da..000000000
--- a/libm/float/i1f.c
+++ /dev/null
@@ -1,177 +0,0 @@
-/* i1f.c
- *
- * Modified Bessel function of order one
- *
- *
- *
- * SYNOPSIS:
- *
- * float x, y, i1f();
- *
- * y = i1f( x );
- *
- *
- *
- * DESCRIPTION:
- *
- * Returns modified Bessel function of order one of the
- * argument.
- *
- * The function is defined as i1(x) = -i j1( ix ).
- *
- * The range is partitioned into the two intervals [0,8] and
- * (8, infinity). Chebyshev polynomial expansions are employed
- * in each interval.
- *
- *
- *
- * ACCURACY:
- *
- * Relative error:
- * arithmetic domain # trials peak rms
- * IEEE 0, 30 100000 1.5e-6 1.6e-7
- *
- *
- */
- /* i1ef.c
- *
- * Modified Bessel function of order one,
- * exponentially scaled
- *
- *
- *
- * SYNOPSIS:
- *
- * float x, y, i1ef();
- *
- * y = i1ef( x );
- *
- *
- *
- * DESCRIPTION:
- *
- * Returns exponentially scaled modified Bessel function
- * of order one of the argument.
- *
- * The function is defined as i1(x) = -i exp(-|x|) j1( ix ).
- *
- *
- *
- * ACCURACY:
- *
- * Relative error:
- * arithmetic domain # trials peak rms
- * IEEE 0, 30 30000 1.5e-6 1.5e-7
- * See i1().
- *
- */
-
-/* i1.c 2 */
-
-
-/*
-Cephes Math Library Release 2.0: March, 1987
-Copyright 1985, 1987 by Stephen L. Moshier
-Direct inquiries to 30 Frost Street, Cambridge, MA 02140
-*/
-
-#include <math.h>
-
-/* Chebyshev coefficients for exp(-x) I1(x) / x
- * in the interval [0,8].
- *
- * lim(x->0){ exp(-x) I1(x) / x } = 1/2.
- */
-
-static float A[] =
-{
- 9.38153738649577178388E-9f,
--4.44505912879632808065E-8f,
- 2.00329475355213526229E-7f,
--8.56872026469545474066E-7f,
- 3.47025130813767847674E-6f,
--1.32731636560394358279E-5f,
- 4.78156510755005422638E-5f,
--1.61760815825896745588E-4f,
- 5.12285956168575772895E-4f,
--1.51357245063125314899E-3f,
- 4.15642294431288815669E-3f,
--1.05640848946261981558E-2f,
- 2.47264490306265168283E-2f,
--5.29459812080949914269E-2f,
- 1.02643658689847095384E-1f,
--1.76416518357834055153E-1f,
- 2.52587186443633654823E-1f
-};
-
-
-/* Chebyshev coefficients for exp(-x) sqrt(x) I1(x)
- * in the inverted interval [8,infinity].
- *
- * lim(x->inf){ exp(-x) sqrt(x) I1(x) } = 1/sqrt(2pi).
- */
-
-static float B[] =
-{
--3.83538038596423702205E-9f,
--2.63146884688951950684E-8f,
--2.51223623787020892529E-7f,
--3.88256480887769039346E-6f,
--1.10588938762623716291E-4f,
--9.76109749136146840777E-3f,
- 7.78576235018280120474E-1f
-};
-
-/* i1.c */
-
-#define fabsf(x) ( (x) < 0 ? -(x) : (x) )
-
-#ifdef ANSIC
-float chbevlf(float, float *, int);
-float expf(float), sqrtf(float);
-#else
-float chbevlf(), expf(), sqrtf();
-#endif
-
-
-float i1f(float xx)
-{
-float x, y, z;
-
-x = xx;
-z = fabsf(x);
-if( z <= 8.0f )
- {
- y = 0.5f*z - 2.0f;
- z = chbevlf( y, A, 17 ) * z * expf(z);
- }
-else
- {
- z = expf(z) * chbevlf( 32.0f/z - 2.0f, B, 7 ) / sqrtf(z);
- }
-if( x < 0.0f )
- z = -z;
-return( z );
-}
-
-/* i1e() */
-
-float i1ef( float xx )
-{
-float x, y, z;
-
-x = xx;
-z = fabsf(x);
-if( z <= 8.0f )
- {
- y = 0.5f*z - 2.0f;
- z = chbevlf( y, A, 17 ) * z;
- }
-else
- {
- z = chbevlf( 32.0f/z - 2.0f, B, 7 ) / sqrtf(z);
- }
-if( x < 0.0f )
- z = -z;
-return( z );
-}