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# isclose

astropy.units.isclose(a, b, rtol=1e-05, atol=None, equal_nan=False)

  Return a boolean array where two arrays are element-wise equal within a tolerance.

  Parameters:
    a, b numpy:array_like or `Quantity`

      Input values or arrays to compare

    rtol numpy:array_like or `Quantity`

      The relative tolerance for the comparison, which defaults to `1e-5`. If `rtol` is a `Quantity`, then it must be dimensionless.

    atol number or `Quantity`

      The absolute tolerance for the comparison. The units (or lack thereof) of `a`, `b`, and `atol` must be consistent with each other. If `None`, `atol` defaults to zero in the appropriate units.

    equal_nan `bool`

      Whether to compare NaN’s as equal. If `True`, NaNs in `a` will be considered equal to NaN’s in `b`.

  Raises:
    `UnitsError`

      If the dimensions of `a`, `b`, or `atol` are incompatible, or if `rtol` is not dimensionless.

  See also

  `allclose`

  Notes

  This is a `Quantity`-aware version of `numpy.isclose()`. However, this differs from the `numpy` function in that the default for the absolute tolerance here is zero instead of `atol=1e-8` in `numpy`, as there is no natural way to set a default absolute tolerance given two inputs that may have differently scaled units.