numpy.frexp#

numpy.frexp(x,[out1,out2,]/,[out=(None,None),]*,where=True,casting='same_kind',order='K',dtype=None,subok=True[,signature])=<ufunc'frexp'>#

Decompose the elements of x into mantissa and twos exponent.

Returns (mantissa,exponent), wherex=mantissa*2**exponent.The mantissa lies in the open interval(-1, 1), while the twosexponent is a signed integer.

Parameters:
xarray_like

Array of numbers to be decomposed.

out1ndarray, optional

Output array for the mantissa. Must have the same shape asx.

out2ndarray, optional

Output array for the exponent. Must have the same shape asx.

outndarray, None, or tuple of ndarray and None, optional

A location into which the result is stored. If provided, it must havea shape that the inputs broadcast to. If not provided or None,a freshly-allocated array is returned. A tuple (possible only as akeyword argument) must have length equal to the number of outputs.

wherearray_like, optional

This condition is broadcast over the input. At locations where thecondition is True, theout array will be set to the ufunc result.Elsewhere, theout array will retain its original value.Note that if an uninitializedout array is created via the defaultout=None, locations within it where the condition is False willremain uninitialized.

**kwargs

For other keyword-only arguments, see theufunc docs.

Returns:
mantissandarray

Floating values between -1 and 1.This is a scalar ifx is a scalar.

exponentndarray

Integer exponents of 2.This is a scalar ifx is a scalar.

See also

ldexp

Computey=x1*2**x2, the inverse offrexp.

Notes

Complex dtypes are not supported, they will raise a TypeError.

Examples

>>>importnumpyasnp>>>x=np.arange(9)>>>y1,y2=np.frexp(x)>>>y1array([ 0.   ,  0.5  ,  0.5  ,  0.75 ,  0.5  ,  0.625,  0.75 ,  0.875,        0.5  ])>>>y2array([0, 1, 2, 2, 3, 3, 3, 3, 4], dtype=int32)>>>y1*2**y2array([ 0.,  1.,  2.,  3.,  4.,  5.,  6.,  7.,  8.])
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