statistics.py 文件源码

def compute(self, data):
        is_integer_type = np.issubdtype(data.water.dtype, np.integer)

        if not is_integer_type:
            raise StatsProcessingError("Attempting to count bit flags on non-integer data. Provided data is: {}"
                                       .format(data.water))

        # 128 == clear and wet, 132 == clear and wet and masked for sea
        # The PQ sea mask that we use is dodgy and should be ignored. It excludes lots of useful data
        wet = ((data.water == 128) | (data.water == 132)).sum(dim='time')
        dry = ((data.water == 0) | (data.water == 4)).sum(dim='time')
        clear = wet + dry
        with np.errstate(divide='ignore', invalid='ignore'):
            frequency = wet / clear
        if self.freq_only:
            return xarray.Dataset({'frequency': frequency}, attrs=dict(crs=data.crs))
        else:
            return xarray.Dataset({'count_wet': wet,
                                   'count_clear': clear,
                                   'frequency': frequency}, attrs=dict(crs=data.crs))