"""Return element-wise remainder of division."""
from __future__ import annotations
from typing import Any, Optional
import numpy
import numpy.typing
import numpoly
from ..baseclass import ndpoly, PolyLike
from ..dispatch import implements_ufunc
REMAINDER_ERROR_MSG = """\
Polynomial division differs from numerical division;
Use ``numpoly.poly_remainder`` to get polynomial remainder."""
[docs]@implements_ufunc(numpy.remainder)
def remainder(
x1: PolyLike,
x2: PolyLike,
out: Optional[ndpoly] = None,
where: numpy.typing.ArrayLike = True,
**kwargs: Any,
) -> ndpoly:
"""
Return element-wise remainder of numerical division.
Args:
x1:
Dividend array.
x2:
Divisor array. If ``x1.shape != x2.shape``, they must be
broadcastable to a common shape (which becomes the shape of the
output).
out:
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:
This condition is broadcast over the input. At locations where the
condition is True, the `out` array will be set to the ufunc result.
Elsewhere, the `out` array will retain its original value. Note
that if an uninitialized `out` array is created via the default
``out=None``, locations within it where the condition is False will
remain uninitialized.
kwargs:
Keyword args passed to numpy.ufunc.
Return:
The element-wise remainder of the quotient ``floor_divide(x1, x2)``.
This is a scalar if both `x1` and `x2` are scalars.
Example:
>>> numpoly.remainder([14, 7], 5)
polynomial([4, 2])
>>> numpoly.remainder(numpoly.variable(), 2) # doctest: +IGNORE_EXCEPTION_DETAIL
Traceback (most recent call last):
...
numpoly.baseclass.FeatureNotSupported: Polynomial division ...
Use ``numpoly.poly_remainder`` to get polynomial remainder.
"""
x1, x2 = numpoly.align_polynomials(x1, x2)
if not x1.isconstant() or not x2.isconstant():
raise numpoly.FeatureNotSupported(REMAINDER_ERROR_MSG)
where = None if where is None else numpy.asarray(where)
return numpoly.polynomial(
numpy.remainder(x1.tonumpy(), x2.tonumpy(), out=out, where=where, **kwargs)
)