BloombergLP::bdldfp::DecimalUtil::logB

Return the FLT_RADIX-based logarithm (i.e., base 10) of the absolute value of the specified x.

Synopsis

Declared in <bdldfp_decimalutil.h>

static
Decimal32
logB(Decimal32 x);

Description

Special value handling: * If x is +/-0, -infinity is returned and the value of the macro ERANGE is stored into errno. * If x is 1, +0 is returned. * If x is +/-infinity, +infinity is returned. * If x is quiet NaN, quiet NaN is returned. * If x is signaling NaN, quiet NaN is returned and the value of the macro EDOM is stored into errno.

Examples: logB( 10.0) ==> 1.0; logB(-100.0) ==> 2.0