cc [ flags ] -I/usr/local/include file(s) -L/usr/local/lib -lmcw [ ... ] #include <mathcw.h> extern float elkm1f (float q); extern double elkm1 (double q); extern long double elkm1l (long double q); extern __float80 elkm1w (__float80 q); extern __float128 elkm1q (__float128 q); extern long_long_double elkm1ll (long_long_double q); extern decimal_float elkm1df (decimal_float q); extern decimal_double elkm1d (decimal_double q); extern decimal_long_double elkm1dl (decimal_long_double q); extern decimal_long_long_double elkm1dll (decimal_long_long_double q);
NB: Functions with prototypes containing underscores in type names may be available only with certain extended compilers.
The companion function elq(k) provides the inverse operation, such that
q = elq(k), k = 1 + elkm1(q), = elk(q).
For q > 1/2, we have k > 0.999995, so this function computes an accurate difference of that value from one.
See M. Abramowitz & I. A. Stegun, Handbook of Mathematical Functions, Chapter 16, for definitions of the Jacobian elliptic, theta, and zeta functions.