public static double nextDown (double d)

Returns the floating-point value adjacent to d in the direction of negative infinity. This method is semantically equivalent to nextAfter(d, Double.NEGATIVE_INFINITY); however, a nextDown implementation may run faster than its equivalent nextAfter call.

Special Cases:

Parameters:
d    starting floating-point value

Returns:  The adjacent floating-point value closer to negative infinity.

Since:  1.8