EXP2M1 3CW "09 March 2006" "mathcw-1.00"

Table of contents


NAME

exp2m1f, exp2m1, exp2m1l, exp2m1w, exp2m1q, exp2m1ll, exp2m1df, exp2m1d, exp2m1dl, exp2m1dll - exponential base-2 function less one

SYNOPSIS

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

#include <mathcw.h>

extern float exp2m1f (float x);

extern double exp2m1 (double x);

extern long double exp2m1l (long double x);

extern __float80 exp2m1w (__float80 x);

extern __float128 exp2m1q (__float128 x);

extern long_long_double exp2m1ll (long_long_double x);

extern decimal_float exp2m1df (decimal_float x);

extern decimal_double exp2m1d (decimal_double x);

extern decimal_long_double exp2m1dl (decimal_long_double x);

extern decimal_long_long_double exp2m1dll (decimal_long_long_double x);

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


DESCRIPTION

Compute the base-2 exponential of x, less one, that is, (2 to the power x) - 1".

For arguments of small magnitude, exp2m1(x) retains full accuracy, while direct computation of exp2(x) - 1 suffers loss of leading significant digits.


RETURN VALUES

Return the base-2 exponential of the argument, less one, or a NaN if the argument is a NaN.

ERRORS

If the argument is a NaN, return the argument, and set errno to EDOM. If the argument is large enough that the function value is too large to represent (i.e., it overflows), return Infinity, and set errno to ERANGE.

SEE ALSO

exp(3CW), expm1(3CW), exp2(3CW), exp8(3CW), exp8m1(3CW), exp10(3CW), exp10m1(3CW), exp16(3CW), exp16m1(3CW), log(3CW), log1p(3CW), log2(3CW), log21p(3CW), log8(3CW), log81p(3CW), log10(3CW), log101p(3CW), log16(3CW), log161p(3CW).