3 * Complete elliptic integral of the second kind
9 * float m1, y, ellpef();
17 * Approximates the integral
23 * E(m) = | sqrt( 1 - m sin t ) dt
28 * Where m = 1 - m1, using the approximation
30 * P(x) - x log x Q(x).
32 * Though there are no singularities, the argument m1 is used
33 * rather than m for compatibility with ellpk().
35 * E(1) = 1; E(0) = pi/2.
41 * arithmetic domain # trials peak rms
42 * IEEE 0, 1 30000 1.1e-7 3.9e-8
47 * message condition value returned
48 * ellpef domain x<0, x>1 0.0
54 /* Elliptic integral of second kind */
57 Cephes Math Library, Release 2.1: February, 1989
58 Copyright 1984, 1987, 1989 by Stephen L. Moshier
59 Direct inquiries to 30 Frost Street, Cambridge, MA 02140
66 1.53552577301013293365E-4,
67 2.50888492163602060990E-3,
68 8.68786816565889628429E-3,
69 1.07350949056076193403E-2,
70 7.77395492516787092951E-3,
71 7.58395289413514708519E-3,
72 1.15688436810574127319E-2,
73 2.18317996015557253103E-2,
74 5.68051945617860553470E-2,
75 4.43147180560990850618E-1,
76 1.00000000000000000299E0
79 3.27954898576485872656E-5,
80 1.00962792679356715133E-3,
81 6.50609489976927491433E-3,
82 1.68862163993311317300E-2,
83 2.61769742454493659583E-2,
84 3.34833904888224918614E-2,
85 4.27180926518931511717E-2,
86 5.85936634471101055642E-2,
87 9.37499997197644278445E-2,
88 2.49999999999888314361E-1
92 float polevlf(float, float *, int), logf(float);
93 float ellpef( float xx)
95 float polevlf(), logf();
103 if( (x <= 0.0) || (x > 1.0) )
107 mtherr( "ellpef", DOMAIN );
110 return( polevlf(x,P,10) - logf(x) * (x * polevlf(x,Q,9)) );