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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/ellpk.c
parent22358dd7ce7bb49792204b698f01a6f69b9c8e08 (diff)
uClibc now has a math library. muahahahaha!
-Erik
Diffstat (limited to 'libm/double/ellpk.c')
-rw-r--r--libm/double/ellpk.c234
1 files changed, 234 insertions, 0 deletions
diff --git a/libm/double/ellpk.c b/libm/double/ellpk.c
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+/* ellpk.c
+ *
+ * Complete elliptic integral of the first kind
+ *
+ *
+ *
+ * SYNOPSIS:
+ *
+ * double m1, y, ellpk();
+ *
+ * y = ellpk( 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
+ * DEC 0,1 16000 3.5e-17 1.1e-17
+ * IEEE 0,1 30000 2.5e-16 6.8e-17
+ *
+ * ERROR MESSAGES:
+ *
+ * message condition value returned
+ * ellpk domain x<0, x>1 0.0
+ *
+ */
+
+/* ellpk.c */
+
+
+/*
+Cephes Math Library, Release 2.8: June, 2000
+Copyright 1984, 1987, 2000 by Stephen L. Moshier
+*/
+
+#include <math.h>
+
+#ifdef DEC
+static unsigned short P[] =
+{
+0035020,0127576,0040430,0051544,
+0036025,0070136,0042703,0153716,
+0036402,0122614,0062555,0077777,
+0036441,0102130,0072334,0025172,
+0036341,0043320,0117242,0172076,
+0036312,0146456,0077242,0154141,
+0036420,0003467,0013727,0035407,
+0036564,0137263,0110651,0020237,
+0036775,0001330,0144056,0020305,
+0037305,0144137,0157521,0141734,
+0040261,0071027,0173721,0147572
+};
+static unsigned short Q[] =
+{
+0034366,0130371,0103453,0077633,
+0035557,0122745,0173515,0113016,
+0036302,0124470,0167304,0074473,
+0036575,0132403,0117226,0117576,
+0036703,0156271,0047124,0147733,
+0036766,0137465,0002053,0157312,
+0037031,0014423,0154274,0176515,
+0037107,0177747,0143216,0016145,
+0037217,0177777,0172621,0074000,
+0037377,0177777,0177776,0156435,
+0040000,0000000,0000000,0000000
+};
+static unsigned short ac1[] = {0040261,0071027,0173721,0147572};
+#define C1 (*(double *)ac1)
+#endif
+
+#ifdef IBMPC
+static unsigned short P[] =
+{
+0x0a6d,0xc823,0x15ef,0x3f22,
+0x7afa,0xc8b8,0xae0b,0x3f62,
+0xb000,0x8cad,0x54b1,0x3f80,
+0x854f,0x0e9b,0x308b,0x3f84,
+0x5e88,0x13d4,0x28da,0x3f7c,
+0x5b0c,0xcfd4,0x59a5,0x3f79,
+0xe761,0xe2fa,0x00e6,0x3f82,
+0x2414,0x7235,0x97d6,0x3f8e,
+0xc419,0x1905,0xa05b,0x3f9f,
+0x387c,0xfbea,0xb90b,0x3fb8,
+0x39ef,0xfefa,0x2e42,0x3ff6
+};
+static unsigned short Q[] =
+{
+0x6ff3,0x30e5,0xd61f,0x3efe,
+0xb2c2,0xbee9,0xf4bc,0x3f4d,
+0x8f27,0x1dd8,0x5527,0x3f78,
+0xd3f0,0x73d2,0xb6a0,0x3f8f,
+0x99fb,0x29ca,0x7b97,0x3f98,
+0x7bd9,0xa085,0xd7e6,0x3f9e,
+0x9faa,0x7b17,0x2322,0x3fa3,
+0xc38d,0xf8d1,0xfffc,0x3fa8,
+0x2f00,0xfeb2,0xffff,0x3fb1,
+0xdba4,0xffff,0xffff,0x3fbf,
+0x0000,0x0000,0x0000,0x3fe0
+};
+static unsigned short ac1[] = {0x39ef,0xfefa,0x2e42,0x3ff6};
+#define C1 (*(double *)ac1)
+#endif
+
+#ifdef MIEEE
+static unsigned short P[] =
+{
+0x3f22,0x15ef,0xc823,0x0a6d,
+0x3f62,0xae0b,0xc8b8,0x7afa,
+0x3f80,0x54b1,0x8cad,0xb000,
+0x3f84,0x308b,0x0e9b,0x854f,
+0x3f7c,0x28da,0x13d4,0x5e88,
+0x3f79,0x59a5,0xcfd4,0x5b0c,
+0x3f82,0x00e6,0xe2fa,0xe761,
+0x3f8e,0x97d6,0x7235,0x2414,
+0x3f9f,0xa05b,0x1905,0xc419,
+0x3fb8,0xb90b,0xfbea,0x387c,
+0x3ff6,0x2e42,0xfefa,0x39ef
+};
+static unsigned short Q[] =
+{
+0x3efe,0xd61f,0x30e5,0x6ff3,
+0x3f4d,0xf4bc,0xbee9,0xb2c2,
+0x3f78,0x5527,0x1dd8,0x8f27,
+0x3f8f,0xb6a0,0x73d2,0xd3f0,
+0x3f98,0x7b97,0x29ca,0x99fb,
+0x3f9e,0xd7e6,0xa085,0x7bd9,
+0x3fa3,0x2322,0x7b17,0x9faa,
+0x3fa8,0xfffc,0xf8d1,0xc38d,
+0x3fb1,0xffff,0xfeb2,0x2f00,
+0x3fbf,0xffff,0xffff,0xdba4,
+0x3fe0,0x0000,0x0000,0x0000
+};
+static unsigned short ac1[] = {
+0x3ff6,0x2e42,0xfefa,0x39ef
+};
+#define C1 (*(double *)ac1)
+#endif
+
+#ifdef UNK
+static double P[] =
+{
+ 1.37982864606273237150E-4,
+ 2.28025724005875567385E-3,
+ 7.97404013220415179367E-3,
+ 9.85821379021226008714E-3,
+ 6.87489687449949877925E-3,
+ 6.18901033637687613229E-3,
+ 8.79078273952743772254E-3,
+ 1.49380448916805252718E-2,
+ 3.08851465246711995998E-2,
+ 9.65735902811690126535E-2,
+ 1.38629436111989062502E0
+};
+
+static double Q[] =
+{
+ 2.94078955048598507511E-5,
+ 9.14184723865917226571E-4,
+ 5.94058303753167793257E-3,
+ 1.54850516649762399335E-2,
+ 2.39089602715924892727E-2,
+ 3.01204715227604046988E-2,
+ 3.73774314173823228969E-2,
+ 4.88280347570998239232E-2,
+ 7.03124996963957469739E-2,
+ 1.24999999999870820058E-1,
+ 4.99999999999999999821E-1
+};
+static double C1 = 1.3862943611198906188E0; /* log(4) */
+#endif
+
+#ifdef ANSIPROT
+extern double polevl ( double, void *, int );
+extern double p1evl ( double, void *, int );
+extern double log ( double );
+#else
+double polevl(), p1evl(), log();
+#endif
+extern double MACHEP, MAXNUM;
+
+double ellpk(x)
+double x;
+{
+
+if( (x < 0.0) || (x > 1.0) )
+ {
+ mtherr( "ellpk", DOMAIN );
+ return( 0.0 );
+ }
+
+if( x > MACHEP )
+ {
+ return( polevl(x,P,10) - log(x) * polevl(x,Q,10) );
+ }
+else
+ {
+ if( x == 0.0 )
+ {
+ mtherr( "ellpk", SING );
+ return( MAXNUM );
+ }
+ else
+ {
+ return( C1 - 0.5 * log(x) );
+ }
+ }
+}