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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/i0f.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/i0f.c')
-rw-r--r--libm/float/i0f.c160
1 files changed, 0 insertions, 160 deletions
diff --git a/libm/float/i0f.c b/libm/float/i0f.c
deleted file mode 100644
index bb62cf60a..000000000
--- a/libm/float/i0f.c
+++ /dev/null
@@ -1,160 +0,0 @@
-/* i0f.c
- *
- * Modified Bessel function of order zero
- *
- *
- *
- * SYNOPSIS:
- *
- * float x, y, i0();
- *
- * y = i0f( x );
- *
- *
- *
- * DESCRIPTION:
- *
- * Returns modified Bessel function of order zero of the
- * argument.
- *
- * The function is defined as i0(x) = j0( 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 4.0e-7 7.9e-8
- *
- */
- /* i0ef.c
- *
- * Modified Bessel function of order zero,
- * exponentially scaled
- *
- *
- *
- * SYNOPSIS:
- *
- * float x, y, i0ef();
- *
- * y = i0ef( x );
- *
- *
- *
- * DESCRIPTION:
- *
- * Returns exponentially scaled modified Bessel function
- * of order zero of the argument.
- *
- * The function is defined as i0e(x) = exp(-|x|) j0( ix ).
- *
- *
- *
- * ACCURACY:
- *
- * Relative error:
- * arithmetic domain # trials peak rms
- * IEEE 0,30 100000 3.7e-7 7.0e-8
- * See i0f().
- *
- */
-
-/* i0.c */
-
-
-/*
-Cephes Math Library Release 2.2: June, 1992
-Copyright 1984, 1987, 1992 by Stephen L. Moshier
-Direct inquiries to 30 Frost Street, Cambridge, MA 02140
-*/
-
-#include <math.h>
-
-/* Chebyshev coefficients for exp(-x) I0(x)
- * in the interval [0,8].
- *
- * lim(x->0){ exp(-x) I0(x) } = 1.
- */
-
-static float A[] =
-{
--1.30002500998624804212E-8f,
- 6.04699502254191894932E-8f,
--2.67079385394061173391E-7f,
- 1.11738753912010371815E-6f,
--4.41673835845875056359E-6f,
- 1.64484480707288970893E-5f,
--5.75419501008210370398E-5f,
- 1.88502885095841655729E-4f,
--5.76375574538582365885E-4f,
- 1.63947561694133579842E-3f,
--4.32430999505057594430E-3f,
- 1.05464603945949983183E-2f,
--2.37374148058994688156E-2f,
- 4.93052842396707084878E-2f,
--9.49010970480476444210E-2f,
- 1.71620901522208775349E-1f,
--3.04682672343198398683E-1f,
- 6.76795274409476084995E-1f
-};
-
-
-/* Chebyshev coefficients for exp(-x) sqrt(x) I0(x)
- * in the inverted interval [8,infinity].
- *
- * lim(x->inf){ exp(-x) sqrt(x) I0(x) } = 1/sqrt(2pi).
- */
-
-static float B[] =
-{
- 3.39623202570838634515E-9f,
- 2.26666899049817806459E-8f,
- 2.04891858946906374183E-7f,
- 2.89137052083475648297E-6f,
- 6.88975834691682398426E-5f,
- 3.36911647825569408990E-3f,
- 8.04490411014108831608E-1f
-};
-
-
-float chbevlf(float, float *, int), expf(float), sqrtf(float);
-
-float i0f( float x )
-{
-float y;
-
-if( x < 0 )
- x = -x;
-if( x <= 8.0f )
- {
- y = 0.5f*x - 2.0f;
- return( expf(x) * chbevlf( y, A, 18 ) );
- }
-
-return( expf(x) * chbevlf( 32.0f/x - 2.0f, B, 7 ) / sqrtf(x) );
-}
-
-
-
-float chbevlf(float, float *, int), expf(float), sqrtf(float);
-
-float i0ef( float x )
-{
-float y;
-
-if( x < 0 )
- x = -x;
-if( x <= 8.0f )
- {
- y = 0.5f*x - 2.0f;
- return( chbevlf( y, A, 18 ) );
- }
-
-return( chbevlf( 32.0f/x - 2.0f, B, 7 ) / sqrtf(x) );
-}