grids.py 文件源码

def _mi(scalararray):
    """Return the average of scalararray(i+1) and scalararray(i)

    A priori, for internal use only.

    Parameters
    ----------
    scalararray : xarray.DataArray
        xarray that should be averaged at i+1/2.

    Returns
    -------
    mi : xarray.DataArray
       averaged xarray, defined at point i+1/2
    """
    mi = ( scalararray.shift(x=-1) + scalararray ) / 2.
    return mi