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sys.stderr.write("sageNumericalOperations: loading...\n")
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#
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def sno_abs_is_power_of_two(number):
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    """
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    Check if the absolute value of a number is power of 2.
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    As of Sage 7.1, the built-in is_power_of_two, only works with integer and
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    returns false for negative ones.
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    """
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    #return is_power_of_two(abs(number))
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    log2number = log(abs(number))/log(2)
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    return log2number.n() == long(log2number.n())
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# End sno_abs_is_power_of_two(number):
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#
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def sno_float_to_rat_pow_of_two_denom(number):
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    """
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    Convert a floating-point number into a rational where the denominator
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    is a power of two
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    """
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    ## Argument checking.
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    if not number.is_real():
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        return None
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    #
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    (sign, mantissa, exponent) = number.sign_mantissa_exponent()
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    #print sign, mantissa, exponent
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    precision = number.prec()
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    if sign == 1:
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        return mantissa / 2^(-exponent)
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    else:
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        return -mantissa / 2^(-exponent)
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# End sno_float_to_rat_pow_of_two_denom.
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sys.stderr.write("\t...sageNumericalOperations loaded.\n")