Laboratoire de l'Informatique et du Parallélisme » Pobyso

print "sageNumericalOperations: loading..."

def sno_abs_is_power_of_two(number):

    """

    Check if the absolute value of a number is power of 2.

    The built-in is_power_of_two, works with many kinds of numbers but 

    returns false for negative ones. 

    """

    return is_power_of_two(abs(number))

# End sno_abs_is_power_of_two(number):

def sno_float_to_rat_pow_of_two_denom(number):

    """

    Convert a floating-point number into a rational where the denominator

    is a power of two

    """

    ## Argument checking.

    if not number.is_real():

        return None

    #

    (sign, mantissa, exponent) = number.sign_mantissa_exponent()

    #print sign, mantissa, exponent

    precision = number.prec()

    if sign == 1:

        return mantissa / 2^(-exponent)

    else:

        return -mantissa / 2^(-exponent)

print "\t...sageNumericalOperations loaded."