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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/double/ellpe.c
parent22358dd7ce7bb49792204b698f01a6f69b9c8e08 (diff)
uClibc now has a math library. muahahahaha!
-Erik
Diffstat (limited to 'libm/double/ellpe.c')
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diff --git a/libm/double/ellpe.c b/libm/double/ellpe.c
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+/* ellpe.c
+ *
+ * Complete elliptic integral of the second kind
+ *
+ *
+ *
+ * SYNOPSIS:
+ *
+ * double m1, y, ellpe();
+ *
+ * y = ellpe( m1 );
+ *
+ *
+ *
+ * DESCRIPTION:
+ *
+ * Approximates the integral
+ *
+ *
+ * pi/2
+ * -
+ * | | 2
+ * E(m) = | sqrt( 1 - m sin t ) dt
+ * | |
+ * -
+ * 0
+ *
+ * Where m = 1 - m1, using the approximation
+ *
+ * P(x) - x log x Q(x).
+ *
+ * Though there are no singularities, the argument m1 is used
+ * rather than m for compatibility with ellpk().
+ *
+ * E(1) = 1; E(0) = pi/2.
+ *
+ *
+ * ACCURACY:
+ *
+ * Relative error:
+ * arithmetic domain # trials peak rms
+ * DEC 0, 1 13000 3.1e-17 9.4e-18
+ * IEEE 0, 1 10000 2.1e-16 7.3e-17
+ *
+ *
+ * ERROR MESSAGES:
+ *
+ * message condition value returned
+ * ellpe domain x<0, x>1 0.0
+ *
+ */
+
+/* ellpe.c */
+
+/* Elliptic integral of second kind */
+
+/*
+Cephes Math Library, Release 2.8: June, 2000
+Copyright 1984, 1987, 1989, 2000 by Stephen L. Moshier
+*/
+
+#include <math.h>
+
+#ifdef UNK
+static double P[] = {
+ 1.53552577301013293365E-4,
+ 2.50888492163602060990E-3,
+ 8.68786816565889628429E-3,
+ 1.07350949056076193403E-2,
+ 7.77395492516787092951E-3,
+ 7.58395289413514708519E-3,
+ 1.15688436810574127319E-2,
+ 2.18317996015557253103E-2,
+ 5.68051945617860553470E-2,
+ 4.43147180560990850618E-1,
+ 1.00000000000000000299E0
+};
+static double Q[] = {
+ 3.27954898576485872656E-5,
+ 1.00962792679356715133E-3,
+ 6.50609489976927491433E-3,
+ 1.68862163993311317300E-2,
+ 2.61769742454493659583E-2,
+ 3.34833904888224918614E-2,
+ 4.27180926518931511717E-2,
+ 5.85936634471101055642E-2,
+ 9.37499997197644278445E-2,
+ 2.49999999999888314361E-1
+};
+#endif
+
+#ifdef DEC
+static unsigned short P[] = {
+0035041,0001364,0141572,0117555,
+0036044,0066032,0130027,0033404,
+0036416,0053617,0064456,0102632,
+0036457,0161100,0061177,0122612,
+0036376,0136251,0012403,0124162,
+0036370,0101316,0151715,0131613,
+0036475,0105477,0050317,0133272,
+0036662,0154232,0024645,0171552,
+0037150,0126220,0047054,0030064,
+0037742,0162057,0167645,0165612,
+0040200,0000000,0000000,0000000
+};
+static unsigned short Q[] = {
+0034411,0106743,0115771,0055462,
+0035604,0052575,0155171,0045540,
+0036325,0030424,0064332,0167756,
+0036612,0052366,0063006,0115175,
+0036726,0070430,0004533,0124654,
+0037011,0022741,0030675,0030711,
+0037056,0174452,0127062,0132122,
+0037157,0177750,0142041,0072523,
+0037277,0177777,0173137,0002627,
+0037577,0177777,0177777,0101101
+};
+#endif
+
+#ifdef IBMPC
+static unsigned short P[] = {
+0x53ee,0x986f,0x205e,0x3f24,
+0xe6e0,0x5602,0x8d83,0x3f64,
+0xd0b3,0xed25,0xcaf1,0x3f81,
+0xf4b1,0x0c4f,0xfc48,0x3f85,
+0x750e,0x22a0,0xd795,0x3f7f,
+0xb671,0xda79,0x1059,0x3f7f,
+0xf6d7,0xea19,0xb167,0x3f87,
+0xbe6d,0x4534,0x5b13,0x3f96,
+0x8607,0x09c5,0x1592,0x3fad,
+0xbd71,0xfdf4,0x5c85,0x3fdc,
+0x0000,0x0000,0x0000,0x3ff0
+};
+static unsigned short Q[] = {
+0x2b66,0x737f,0x31bc,0x3f01,
+0x296c,0xbb4f,0x8aaf,0x3f50,
+0x5dfe,0x8d1b,0xa622,0x3f7a,
+0xd350,0xccc0,0x4a9e,0x3f91,
+0x7535,0x012b,0xce23,0x3f9a,
+0xa639,0x2637,0x24bc,0x3fa1,
+0x568a,0x55c6,0xdf25,0x3fa5,
+0x2eaa,0x1884,0xfffd,0x3fad,
+0xe0b3,0xfecb,0xffff,0x3fb7,
+0xf048,0xffff,0xffff,0x3fcf
+};
+#endif
+
+#ifdef MIEEE
+static unsigned short P[] = {
+0x3f24,0x205e,0x986f,0x53ee,
+0x3f64,0x8d83,0x5602,0xe6e0,
+0x3f81,0xcaf1,0xed25,0xd0b3,
+0x3f85,0xfc48,0x0c4f,0xf4b1,
+0x3f7f,0xd795,0x22a0,0x750e,
+0x3f7f,0x1059,0xda79,0xb671,
+0x3f87,0xb167,0xea19,0xf6d7,
+0x3f96,0x5b13,0x4534,0xbe6d,
+0x3fad,0x1592,0x09c5,0x8607,
+0x3fdc,0x5c85,0xfdf4,0xbd71,
+0x3ff0,0x0000,0x0000,0x0000
+};
+static unsigned short Q[] = {
+0x3f01,0x31bc,0x737f,0x2b66,
+0x3f50,0x8aaf,0xbb4f,0x296c,
+0x3f7a,0xa622,0x8d1b,0x5dfe,
+0x3f91,0x4a9e,0xccc0,0xd350,
+0x3f9a,0xce23,0x012b,0x7535,
+0x3fa1,0x24bc,0x2637,0xa639,
+0x3fa5,0xdf25,0x55c6,0x568a,
+0x3fad,0xfffd,0x1884,0x2eaa,
+0x3fb7,0xffff,0xfecb,0xe0b3,
+0x3fcf,0xffff,0xffff,0xf048
+};
+#endif
+
+#ifdef ANSIPROT
+extern double polevl ( double, void *, int );
+extern double log ( double );
+#else
+double polevl(), log();
+#endif
+
+double ellpe(x)
+double x;
+{
+
+if( (x <= 0.0) || (x > 1.0) )
+ {
+ if( x == 0.0 )
+ return( 1.0 );
+ mtherr( "ellpe", DOMAIN );
+ return( 0.0 );
+ }
+return( polevl(x,P,10) - log(x) * (x * polevl(x,Q,9)) );
+}