Function get_xy

src/wrf/interputils.py:266–323

Return the x,y points for the horizontal cross section line. Args: var (:class:`xarray.DataArray` or :class:`numpy.ndarray`): A variable that contains a :attr:`shape` attribute. pivot_point (:obj:`tuple` or :obj:`list`, optional): A :obj:`tuple` or :obj

(var, pivot_point=None, angle=None,
           start_point=None, end_point=None)

def get_xy(var, pivot_point=None, angle=None,
           start_point=None, end_point=None):
    """Return the x,y points for the horizontal cross section line.

    Args:

        var (:class:`xarray.DataArray` or :class:`numpy.ndarray`): A variable
            that contains a :attr:`shape` attribute.

        pivot_point (:obj:`tuple` or :obj:`list`, optional): A
            :obj:`tuple` or :obj:`list` with two entries,
            in the form of [x, y] (or [west_east, south_north]), which
            indicates the x,y location through which the plane will pass.
            Must also specify `angle`.

        angle (:obj:`float`, optional): Only valid for cross sections where
            a plane will be plotted through
            a given point on the model domain. 0.0 represents a S-N cross
            section.  90.0 is a W-E cross section.

        start_point (:obj:`tuple` or :obj:`list`, optional): A
            :obj:`tuple` or :obj:`list` with two entries, in the form of
            [x, y] (or [west_east, south_north]), which indicates the start
            x,y location through which the plane will pass.

        end_point (:obj:`tuple` or :obj:`list`, optional): A
            :obj:`tuple` or :obj:`list` with two entries, in the form of
            [x, y] (or [west_east, south_north]), which indicates the end x,y
            location through which the plane will pass.

    Returns:

        :class:`np.ndarray`: A two-dimensional array with the left index
        representing each point along the line, and the rightmost dimension
        having two values for the x and y coordinates [0=X, 1=Y].

    """
    if pivot_point is not None:
        pos_pivot = to_positive_idxs(var.shape[-2:], pivot_point)
    else:
        pos_pivot = pivot_point

    if start_point is not None:
        pos_start = to_positive_idxs(var.shape[-2:], start_point)
    else:
        pos_start = start_point

    if end_point is not None:
        pos_end = to_positive_idxs(var.shape[-2:], end_point)
    else:
        pos_end = start_point

    xdim = var.shape[-1]
    ydim = var.shape[-2]

    xy = _calc_xy(xdim, ydim, pos_pivot, angle, pos_start, pos_end)

    return xy