ipol.py 文件源码

def cart2irregular_interp(cartgrid, values, newgrid, **kwargs):
    """
    Interpolate array ``values`` defined by cartesian coordinate array
    ``cartgrid`` to new coordinates defined by ``newgrid`` using
    nearest neighbour, linear or cubic interpolation

    .. versionadded:: 0.6.0

    Slow for large arrays

    Keyword arguments are fed to :func:`scipy:scipy.interpolate.griddata`

    Parameters
    ----------
    cartgrid : numpy ndarray
        3 dimensional array (nx, ny, lon/lat) of floats;
    values : numpy 2d-array
        2 dimensional array (nx, ny) of data values
    newgrid : numpy ndarray
        Nx2 dimensional array (..., lon/lat) of floats
    kwargs : :func:`scipy:scipy.interpolate.griddata`

    Returns
    -------
    interp : numpy ndarray
        array with interpolated values of size N
    """

    # TODO: dimension checking

    newshape = newgrid.shape[:-1]

    cart_arr = cartgrid.reshape(-1, cartgrid.shape[-1])
    new_arr = newgrid.reshape(-1, newgrid.shape[-1])

    if values.ndim > 1:
        values = values.ravel()

    interp = griddata(cart_arr, values, new_arr, **kwargs)
    interp = interp.reshape(newshape)

    return interp