log1pd64(3M)															      log1pd64(3M)

NAME

       log1pd64(), log1pd128(), log1pd32() - decimal natural logarithm of one-plus-argument functions

SYNOPSIS

DESCRIPTION

       The function computes the logarithmic function but may be more accurate for very small values of x.

       The and functions are useful to guarantee that financial calculations of (((1+x)**n)-1)/x are accurate when x is very small, namely:

       The preceding example might be applicable when calculating small daily interest rates.

       is a version of it takes a argument and returns a result.

       is a version of it takes a argument and returns a result.

       These math functions are supported for HP-UX 11i Version 3 September 2008 Update and forward.

USAGE

       To use any of these functions, compile with the option.

       Make sure your program defines and then includes

       Link in the math library by specifying or on the linking command line.

       For more information, see the at the following site:

RETURN VALUE

       If x is +infinity, returns +infinity.

       If x is -1, returns -infinity and raises the divide-by-zero exception.

       If x is less than -1, returns NaN and raises the invalid exception.

       If x is NaN, returns NaN.

       raises the inexact exception whenever a rounded result does not equal the mathematical result.

ERRORS

       If x is less than -1, sets to

       If x is -1, sets to

SEE ALSO

       annuity(3M), compound(3M), expm1d64(3M), log10d64(3M), log2d64(3M), logd64(3M), math(5).

STANDARDS CONFORMANCE

       These functions conform to ISO/IEC TR 24732, "Extension for the programming language C to support decimal floating-point arithmetic".

							     HP Integrity Server Only						      log1pd64(3M)