Math.modf
From OpenEUO
math.modf (x)
Returns two numbers, the integral part of x and the fractional part of x.
Numbers in Lua are doubles and doubles under Windows are a 64-bit floating point type: 1 bit for sign, 11 bits for the exponent, and 52 bits for the mantissa. Its range is +/–1.7E308 with at least 15 digits of precision.