def arange()

in core/maxframe/tensor/datasource/arange.py [0:0]


def arange(*args, **kwargs):
    """
    Return evenly spaced values within a given interval.

    Values are generated within the half-open interval ``[start, stop)``
    (in other words, the interval including `start` but excluding `stop`).
    For integer arguments the function is equivalent to the Python built-in
    `range <http://docs.python.org/lib/built-in-funcs.html>`_ function,
    but returns a tensor rather than a list.

    When using a non-integer step, such as 0.1, the results will often not
    be consistent.  It is better to use ``linspace`` for these cases.

    Parameters
    ----------
    start : number, optional
        Start of interval.  The interval includes this value.  The default
        start value is 0.
    stop : number
        End of interval.  The interval does not include this value, except
        in some cases where `step` is not an integer and floating point
        round-off affects the length of `out`.
    step : number, optional
        Spacing between values.  For any output `out`, this is the distance
        between two adjacent values, ``out[i+1] - out[i]``.  The default
        step size is 1.  If `step` is specified as a position argument,
        `start` must also be given.
    dtype : dtype
        The type of the output tensor.  If `dtype` is not given, infer the data
        type from the other input arguments.
    gpu : bool, optional
        Allocate the tensor on GPU if True, False as default

    Returns
    -------
    arange : Tensor
        Tensor of evenly spaced values.

        For floating point arguments, the length of the result is
        ``ceil((stop - start)/step)``.  Because of floating point overflow,
        this rule may result in the last element of `out` being greater
        than `stop`.

    See Also
    --------
    linspace : Evenly spaced numbers with careful handling of endpoints.
    ogrid: Tensors of evenly spaced numbers in N-dimensions.
    mgrid: Grid-shaped tensors of evenly spaced numbers in N-dimensions.

    Examples
    --------
    >>> import maxframe.tensor as mt

    >>> mt.arange(3).execute()
    array([0, 1, 2])
    >>> mt.arange(3.0).execute()
    array([ 0.,  1.,  2.])
    >>> mt.arange(3,7).execute()
    array([3, 4, 5, 6])
    >>> mt.arange(3,7,2).execute()
    array([3, 5])
    """
    kw_args = [kwargs.get("start"), kwargs.get("stop"), kwargs.get("step")]
    kw_def = any(arg is not None for arg in kw_args)
    dtype = None
    if not kw_def:
        if len(args) == 1:
            start = 0
            stop = args[0]
            step = 1
        elif len(args) == 2:
            start = args[0]
            stop = args[1]
            step = 1
        elif len(args) == 3:
            start, stop, step = args
        elif len(args) == 4:
            start, stop, step, dtype = args
            dtype = np.dtype(dtype)
        else:
            raise TypeError("Required argument 'start' (pos 1) not found")
    else:
        names = "start", "stop", "step"
        for i, arg in enumerate(args):
            if kw_args[i] is not None:
                raise TypeError(
                    f"Argument given by name ('{names[i]}') and position ({i})"
                )
            kw_args[i] = arg
        start, stop, step = kw_args

    if dtype is None:
        if "dtype" in kwargs:
            dtype = np.dtype(kwargs["dtype"])
        else:
            dtype = np.arange(0, type(stop)(1), step).dtype

    start, stop = dtype.type(start), dtype.type(stop)
    if dtype == np.datetime64 and not start:
        raise ValueError(
            "arange requires both a start and a stop for MaxFrame datetime64 ranges"
        )
    if dtype == np.datetime64:
        span = np.array([stop - start])
        span[0] = step
        step = span[0]
        dtype = np.dtype(stop.dtype)
    else:
        step = dtype.type(step)
    size = max(int(np.ceil(np.true_divide(stop - start, step))), 0)

    op = TensorArange(start, stop, step, dtype=dtype, gpu=kwargs.get("gpu", False))
    shape = (size,)
    return op(shape, chunk_size=kwargs.pop("chunk_size", None))