ELWG 3CW "01 March 2010" "mathcw-1.00"

Table of contents


NAME

elwgf, elwg, elwgl, elwgw, elwgq, elwgll, elwgdf, elwgd, elwgdl, elwgdll - Weierstrass elliptic function support routines

SYNOPSIS

cc [ flags ] -I/usr/local/include file(s) -L/usr/local/lib -lmcw [ ... ]

#include <mathcw.h>

extern void elwgf (float *pg2, float *pg3, float e1, float e2);

extern void elwg (double *pg2, double *pg3, double e1, double e2);

extern void elwgl (long double *pg2, long double *pg3, long double e1, long double e2);

extern void elwgw (__float80 *pg2, __float80 *pg3, __float80 e1, __float80 e2);

extern void elwgq (__float128 *pg2, __float128 *pg3, __float128 e1, __float128 e2);

extern void elwgll (long_long_double *pg2, long_long_double *pg3,
                    long_long_double e1, long_long_double e2);

extern void elwgdf (decimal_float *pg2, decimal_float *pg3,
                    decimal_float e1, decimal_float e2);

extern void elwgd (decimal_double *pg2, decimal_double *pg3,
                   decimal_double e1, decimal_double e2);

extern void elwgdl (decimal_long_double *pg2, decimal_long_double *pg3,
                    decimal_long_double e1, decimal_long_double e2);

extern void elwgdll (decimal_long_long_double *pg2, decimal_long_long_double *pg3,
                    decimal_long_long_double e1, decimal_long_long_double e2);

NB: Functions with prototypes containing underscores in type names may be available only with certain extended compilers.


DESCRIPTION

Given e1 and e2, which are any two of the three roots of the Weierstrass cubic polynomial, where the sum of the roots is zero, compute the coefficients g2 and g3 of the polynomial C(t) = 4 * t**3 - g2 * t - g3.

For the reverse conversion, see elwe(3CW0.

See M. Abramowitz & I. A. Stegun, Handbook of Mathematical Functions, Chapter 18, for definitions of the Weierstrass elliptic, sigma, and zeta functions.


RETURN VALUES

Return the coefficients g2 and g3 through the pointer arguments, but suppress storage if the corresponding pointer is NULL.

ERRORS

If any argument is a NaN, set errno to EDOM and set the two results to that argument.

SEE ALSO

elk(3CW), elkm1(3CW), elq(3CW), elq1p(3CW), elqc(3CW), elqc1p(3CW), elwdp(3CW), elwe(3CW), elwip(3CW), elwk(3CW), elwo(3CW), elwp(3CW), elws(3CW), elwz(3CW),