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authorEric Andersen <andersen@codepoet.org>2001-05-10 00:40:28 +0000
committerEric Andersen <andersen@codepoet.org>2001-05-10 00:40:28 +0000
commit1077fa4d772832f77a677ce7fb7c2d513b959e3f (patch)
tree579bee13fb0b58d2800206366ec2caecbb15f3fc /libm/ldouble/ellpkl.c
parent22358dd7ce7bb49792204b698f01a6f69b9c8e08 (diff)
uClibc now has a math library. muahahahaha!
-Erik
Diffstat (limited to 'libm/ldouble/ellpkl.c')
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+/* ellpkl.c
+ *
+ * Complete elliptic integral of the first kind
+ *
+ *
+ *
+ * SYNOPSIS:
+ *
+ * long double m1, y, ellpkl();
+ *
+ * y = ellpkl( m1 );
+ *
+ *
+ *
+ * DESCRIPTION:
+ *
+ * Approximates the integral
+ *
+ *
+ *
+ * pi/2
+ * -
+ * | |
+ * | dt
+ * K(m) = | ------------------
+ * | 2
+ * | | sqrt( 1 - m sin t )
+ * -
+ * 0
+ *
+ * where m = 1 - m1, using the approximation
+ *
+ * P(x) - log x Q(x).
+ *
+ * The argument m1 is used rather than m so that the logarithmic
+ * singularity at m = 1 will be shifted to the origin; this
+ * preserves maximum accuracy.
+ *
+ * K(0) = pi/2.
+ *
+ * ACCURACY:
+ *
+ * Relative error:
+ * arithmetic domain # trials peak rms
+ * IEEE 0,1 10000 1.1e-19 3.3e-20
+ *
+ * ERROR MESSAGES:
+ *
+ * message condition value returned
+ * ellpkl domain x<0, x>1 0.0
+ *
+ */
+
+/* ellpkl.c */
+
+
+/*
+Cephes Math Library, Release 2.3: October, 1995
+Copyright 1984, 1987, 1995 by Stephen L. Moshier
+*/
+
+#include <math.h>
+
+#if UNK
+static long double P[13] = {
+ 1.247539729154838838628E-6L,
+ 2.149421654232011240659E-4L,
+ 2.265267575136470585139E-3L,
+ 6.723088676584254248821E-3L,
+ 8.092066790639263075808E-3L,
+ 5.664069509748147028621E-3L,
+ 4.579865994050801042865E-3L,
+ 5.797368411662027645234E-3L,
+ 8.767698209432225911803E-3L,
+ 1.493761594388688915057E-2L,
+ 3.088514457872042326871E-2L,
+ 9.657359027999314232753E-2L,
+ 1.386294361119890618992E0L,
+};
+static long double Q[12] = {
+ 5.568631677757315398993E-5L,
+ 1.036110372590318802997E-3L,
+ 5.500459122138244213579E-3L,
+ 1.337330436245904844528E-2L,
+ 2.033103735656990487115E-2L,
+ 2.522868345512332304268E-2L,
+ 3.026786461242788135379E-2L,
+ 3.738370118296930305919E-2L,
+ 4.882812208418620146046E-2L,
+ 7.031249999330222751046E-2L,
+ 1.249999999999978263154E-1L,
+ 4.999999999999999999924E-1L,
+};
+static long double C1 = 1.386294361119890618834L; /* log(4) */
+#endif
+#if IBMPC
+static short P[] = {
+0xf098,0xad01,0x2381,0xa771,0x3feb, XPD
+0xd6ed,0xea22,0x1922,0xe162,0x3ff2, XPD
+0x3733,0xe2f1,0xe226,0x9474,0x3ff6, XPD
+0x3031,0x3c9d,0x5aff,0xdc4d,0x3ff7, XPD
+0x9a46,0x4310,0x968e,0x8494,0x3ff8, XPD
+0xbe4c,0x3ff2,0xa8a7,0xb999,0x3ff7, XPD
+0xf35c,0x0eaf,0xb355,0x9612,0x3ff7, XPD
+0xbc56,0x8fd4,0xd9dd,0xbdf7,0x3ff7, XPD
+0xc01e,0x867f,0x6444,0x8fa6,0x3ff8, XPD
+0x4ba3,0x6392,0xe6fd,0xf4bc,0x3ff8, XPD
+0x62c3,0xbb12,0xd7bc,0xfd02,0x3ff9, XPD
+0x08fe,0x476c,0x5fdf,0xc5c8,0x3ffb, XPD
+0x79ad,0xd1cf,0x17f7,0xb172,0x3fff, XPD
+};
+static short Q[] = {
+0x96a4,0x8474,0xba33,0xe990,0x3ff0, XPD
+0xe5a7,0xa50e,0x1854,0x87ce,0x3ff5, XPD
+0x8999,0x72e3,0x3205,0xb43d,0x3ff7, XPD
+0x3255,0x13eb,0xb438,0xdb1b,0x3ff8, XPD
+0xb717,0x497f,0x4691,0xa68d,0x3ff9, XPD
+0x30be,0x8c6b,0x624b,0xceac,0x3ff9, XPD
+0xa858,0x2a0d,0x5014,0xf7f4,0x3ff9, XPD
+0x8615,0xbfa6,0xa6df,0x991f,0x3ffa, XPD
+0x103c,0xa076,0xff37,0xc7ff,0x3ffa, XPD
+0xf508,0xc515,0xffff,0x8fff,0x3ffb, XPD
+0x1af5,0xfffb,0xffff,0xffff,0x3ffb, XPD
+0x0000,0x0000,0x0000,0x8000,0x3ffe, XPD
+};
+static unsigned short ac1[] = {
+0x79ac,0xd1cf,0x17f7,0xb172,0x3fff, XPD
+};
+#define C1 (*(long double *)ac1)
+#endif
+
+#ifdef MIEEE
+static long P[39] = {
+0x3feb0000,0xa7712381,0xad01f098,
+0x3ff20000,0xe1621922,0xea22d6ed,
+0x3ff60000,0x9474e226,0xe2f13733,
+0x3ff70000,0xdc4d5aff,0x3c9d3031,
+0x3ff80000,0x8494968e,0x43109a46,
+0x3ff70000,0xb999a8a7,0x3ff2be4c,
+0x3ff70000,0x9612b355,0x0eaff35c,
+0x3ff70000,0xbdf7d9dd,0x8fd4bc56,
+0x3ff80000,0x8fa66444,0x867fc01e,
+0x3ff80000,0xf4bce6fd,0x63924ba3,
+0x3ff90000,0xfd02d7bc,0xbb1262c3,
+0x3ffb0000,0xc5c85fdf,0x476c08fe,
+0x3fff0000,0xb17217f7,0xd1cf79ad,
+};
+static long Q[36] = {
+0x3ff00000,0xe990ba33,0x847496a4,
+0x3ff50000,0x87ce1854,0xa50ee5a7,
+0x3ff70000,0xb43d3205,0x72e38999,
+0x3ff80000,0xdb1bb438,0x13eb3255,
+0x3ff90000,0xa68d4691,0x497fb717,
+0x3ff90000,0xceac624b,0x8c6b30be,
+0x3ff90000,0xf7f45014,0x2a0da858,
+0x3ffa0000,0x991fa6df,0xbfa68615,
+0x3ffa0000,0xc7ffff37,0xa076103c,
+0x3ffb0000,0x8fffffff,0xc515f508,
+0x3ffb0000,0xffffffff,0xfffb1af5,
+0x3ffe0000,0x80000000,0x00000000,
+};
+static unsigned long ac1[] = {
+0x3fff0000,0xb17217f7,0xd1cf79ac
+};
+#define C1 (*(long double *)ac1)
+#endif
+
+
+#ifdef ANSIPROT
+extern long double polevll ( long double, void *, int );
+extern long double logl ( long double );
+#else
+long double polevll(), logl();
+#endif
+extern long double MACHEPL, MAXNUML;
+
+long double ellpkl(x)
+long double x;
+{
+
+if( (x < 0.0L) || (x > 1.0L) )
+ {
+ mtherr( "ellpkl", DOMAIN );
+ return( 0.0L );
+ }
+
+if( x > MACHEPL )
+ {
+ return( polevll(x,P,12) - logl(x) * polevll(x,Q,11) );
+ }
+else
+ {
+ if( x == 0.0L )
+ {
+ mtherr( "ellpkl", SING );
+ return( MAXNUML );
+ }
+ else
+ {
+ return( C1 - 0.5L * logl(x) );
+ }
+ }
+}