numpy.frexp — NumPy v1.11 Manual (original) (raw)
numpy.frexp(_x_[, out1, _out2_]) = <ufunc 'frexp'>¶
Decompose the elements of x into mantissa and twos exponent.
Returns (mantissa, exponent), where x = mantissa * 2**exponent`. The mantissa is lies in the open interval(-1, 1), while the twos exponent is a signed integer.
| Parameters: | x : array_like Array of numbers to be decomposed. out1 : ndarray, optional Output array for the mantissa. Must have the same shape as x. out2 : ndarray, optional Output array for the exponent. Must have the same shape as x. |
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| Returns: | (mantissa, exponent) : tuple of ndarrays, (float, int) mantissa is a float array with values between -1 and 1.exponent is an int array which represents the exponent of 2. |
See also
Compute y = x1 * 2**x2, the inverse of frexp.
Notes
Complex dtypes are not supported, they will raise a TypeError.
Examples
x = np.arange(9) y1, y2 = np.frexp(x) y1 array([ 0. , 0.5 , 0.5 , 0.75 , 0.5 , 0.625, 0.75 , 0.875, 0.5 ]) y2 array([0, 1, 2, 2, 3, 3, 3, 3, 4]) y1 * 2**y2 array([ 0., 1., 2., 3., 4., 5., 6., 7., 8.])