/**
* Returns the largest power of 10 that is less than or equal to the
* the specified positive value.
*
* @param d the <code>double</code> number.
* @return <code>floor(Log10(abs(d)))</code>
* @throws ArithmeticException if <code>d <= 0<code> or <code>d</code>
* is <code>NaN</code> or <code>Infinity</code>.
**/
public static int floorLog10(double d) {
int guess = (int) (LOG2_DIV_LOG10 * MathLib.floorLog2(d));
double pow10 = MathLib.toDoublePow10(1, guess);
if ((pow10 <= d) && (pow10 * 10 > d)) return guess;
if (pow10 > d) return guess - 1;
return guess + 1;
}
