xarray.ufuncs.sign¶
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xarray.ufuncs.
sign
= <xarray.ufuncs._UFuncDispatcher object>¶ xarray specific variant of numpy.sign. Handles xarray.Dataset, xarray.DataArray, xarray.Variable, numpy.ndarray and dask.array.Array objects with automatic dispatching.
Documentation from numpy:
sign(x, /, out=None, *, where=True, casting=’same_kind’, order=’K’, dtype=None, subok=True[, signature, extobj])
Returns an element-wise indication of the sign of a number.
The sign function returns
-1 if x < 0, 0 if x==0, 1 if x > 0
. nan is returned for nan inputs.For complex inputs, the sign function returns
sign(x.real) + 0j if x.real != 0 else sign(x.imag) + 0j
.complex(nan, 0) is returned for complex nan inputs.
Parameters: - x : array_like
Input values.
- out : ndarray, None, or tuple of ndarray and None, optional
A location into which the result is stored. If provided, it must have a shape that the inputs broadcast to. If not provided or None, a freshly-allocated array is returned. A tuple (possible only as a keyword argument) must have length equal to the number of outputs.
- where : array_like, optional
Values of True indicate to calculate the ufunc at that position, values of False indicate to leave the value in the output alone.
- **kwargs
For other keyword-only arguments, see the ufunc docs.
Returns: - y : ndarray
The sign of x.
Notes
There is more than one definition of sign in common use for complex numbers. The definition used here is equivalent to \(x/\sqrt{x*x}\) which is different from a common alternative, \(x/|x|\).
Examples
>>> np.sign([-5., 4.5]) array([-1., 1.]) >>> np.sign(0) 0 >>> np.sign(5-2j) (1+0j)