def calc()

in analysis/webservice/algorithms_spark/MaximaMinimaSpark.py [0:0]


    def calc(self, compute_options, **args):
        """

        :param compute_options: StatsComputeOptions
        :param args: dict
        :return:
        """

        ds, bbox, start_time, end_time, nparts_requested, min_elevation, max_elevation = self.parse_arguments(compute_options)
        self._setQueryParams(ds,
                             (float(bbox.bounds[1]),
                              float(bbox.bounds[3]),
                              float(bbox.bounds[0]),
                              float(bbox.bounds[2])),
                             start_time,
                             end_time)

        # for single timestamp, get bounds of all tiles
        nexus_tiles = self._find_global_tile_set()

        if len(nexus_tiles) == 0:
            raise NoDataException(reason="No data found for selected timeframe")

        self.log.debug('Found {0} tiles'.format(len(nexus_tiles)))
        print(('Found {} tiles'.format(len(nexus_tiles))))

        daysinrange = self._tile_service.find_days_in_range_asc(bbox.bounds[1],
                                                                bbox.bounds[3],
                                                                bbox.bounds[0],
                                                                bbox.bounds[2],
                                                                ds,
                                                                start_time,
                                                                end_time)
        ndays = len(daysinrange)
        if ndays == 0:
            raise NoDataException(reason="No data found for selected timeframe")
        self.log.debug('Found {0} days in range'.format(ndays))
        for i, d in enumerate(daysinrange):
            self.log.debug('{0}, {1}'.format(i, datetime.utcfromtimestamp(d)))


        self.log.debug('Using Native resolution: lat_res={0}, lon_res={1}'.format(self._latRes, self._lonRes))
        self.log.debug('nlats={0}, nlons={1}'.format(self._nlats, self._nlons))
        self.log.debug('center lat range = {0} to {1}'.format(self._minLatCent,
                                                              self._maxLatCent))
        self.log.debug('center lon range = {0} to {1}'.format(self._minLonCent,
                                                              self._maxLonCent))

        # Create array of tuples to pass to Spark map function
        nexus_tiles_spark = np.array([[self._find_tile_bounds(t),
                              self._startTime, self._endTime,
                              self._ds] for t in nexus_tiles], dtype='object')

        # Remove empty tiles (should have bounds set to None)
        bad_tile_inds = np.where([t[0] is None for t in nexus_tiles_spark])[0]
        for i in np.flipud(bad_tile_inds):
            del nexus_tiles_spark[i]

        # Expand Spark map tuple array by duplicating each entry N times,
        # where N is the number of ways we want the time dimension carved up.
        # Set the time boundaries for each of the Spark map tuples so that
        # every Nth element in the array gets the same time bounds.
        max_time_parts = 72
        num_time_parts = min(max_time_parts, ndays)

        spark_part_time_ranges = np.tile(np.array([a[[0,-1]] for a in np.array_split(np.array(daysinrange), num_time_parts)]), (len(nexus_tiles_spark),1))
        nexus_tiles_spark = np.repeat(nexus_tiles_spark, num_time_parts, axis=0)
        nexus_tiles_spark[:, 1:3] = spark_part_time_ranges

        # Launch Spark computations
        spark_nparts = self._spark_nparts(nparts_requested)
        self.log.info('Using {} partitions'.format(spark_nparts))

        rdd = self._sc.parallelize(nexus_tiles_spark, spark_nparts)
        max_min_part = rdd.map(partial(self._map, self._tile_service_factory, min_elevation, max_elevation))
        max_min_count = \
            max_min_part.combineByKey(lambda val: val,
                                        lambda x, val: (np.maximum(x[0], val[0]),   # Max
                                                        np.minimum(x[1], val[1]),   # Min
                                                        np.maximum(x[2], val[2]),  # Absolute Max
                                                        np.minimum(x[3], val[3]),  # Absolute Min
                                                        (x[4] + val[4])),           # Count
                                        lambda x, y: (np.maximum(x[0], y[0]),   # Max
                                                      np.minimum(x[1], y[1]),   # Min
                                                      np.maximum(x[2], y[2]),   # Absolute Max
                                                      np.minimum(x[3], y[3]),   # Absolute Min
                                                      (x[4] + y[4])))           # Count
        fill = self._fill
        avg_tiles = \
            max_min_count.map(lambda bounds_max_tile_min_tile_abs_max_tile_abs_min_tile_cnt_tile:
                              (bounds_max_tile_min_tile_abs_max_tile_abs_min_tile_cnt_tile[0], [[{'maxima': bounds_max_tile_min_tile_abs_max_tile_abs_min_tile_cnt_tile[1][0][y, x] if (bounds_max_tile_min_tile_abs_max_tile_abs_min_tile_cnt_tile[1][4][y, x] > 0) else fill,
                                          'minima': bounds_max_tile_min_tile_abs_max_tile_abs_min_tile_cnt_tile[1][1][y, x] if (bounds_max_tile_min_tile_abs_max_tile_abs_min_tile_cnt_tile[1][4][y, x] > 0) else fill,
                                          'absolute_maxima': bounds_max_tile_min_tile_abs_max_tile_abs_min_tile_cnt_tile[1][2][y, x] if (bounds_max_tile_min_tile_abs_max_tile_abs_min_tile_cnt_tile[1][4][y, x] > 0) else fill,
                                          'absolute_minima': bounds_max_tile_min_tile_abs_max_tile_abs_min_tile_cnt_tile[1][3][y, x] if (bounds_max_tile_min_tile_abs_max_tile_abs_min_tile_cnt_tile[1][4][y, x] > 0) else fill,
                                          'cnt': bounds_max_tile_min_tile_abs_max_tile_abs_min_tile_cnt_tile[1][4][y, x]}
                                         for x in range(bounds_max_tile_min_tile_abs_max_tile_abs_min_tile_cnt_tile[1][0].shape[1])]
                                        for y in range(bounds_max_tile_min_tile_abs_max_tile_abs_min_tile_cnt_tile[1][0].shape[0])])).collect()

        # Combine subset results to produce global map.
        #
        # The tiles below are NOT Nexus objects.  They are tuples
        # with the time avg map data and lat-lon bounding box.
        a = np.zeros((self._nlats, self._nlons, 4), dtype=np.float64, order='C')
        n = np.zeros((self._nlats, self._nlons), dtype=np.uint32, order='C')
        for tile in avg_tiles:
            if tile is not None:
                ((tile_min_lat, tile_max_lat, tile_min_lon, tile_max_lon),
                 tile_stats) = tile
                # need to arrange max/min data in tuple to pull out later - can this step be skipped?
                tile_data = np.ma.array(
                    [[(tile_stats[y][x]['maxima'], tile_stats[y][x]['minima'], tile_stats[y][x]['absolute_maxima'], tile_stats[y][x]['absolute_minima']) for x in range(len(tile_stats[0]))] for y in range(len(tile_stats))])
                tile_cnt = np.array(
                    [[tile_stats[y][x]['cnt'] for x in range(len(tile_stats[0]))] for y in range(len(tile_stats))])
                tile_data.mask = ~(tile_cnt.astype(bool))
                y0 = self._lat2ind(tile_min_lat)
                y1 = y0 + tile_data.shape[0] - 1
                x0 = self._lon2ind(tile_min_lon)
                x1 = x0 + tile_data.shape[1] - 1
                if np.any(np.logical_not(tile_data.mask)):
                    self.log.debug(
                        'writing tile lat {0}-{1}, lon {2}-{3}, map y {4}-{5}, map x {6}-{7}'.format(tile_min_lat,
                                                                                                     tile_max_lat,
                                                                                                     tile_min_lon,
                                                                                                     tile_max_lon, y0,
                                                                                                     y1, x0, x1))
                    a[y0:y1 + 1, x0:x1 + 1] = tile_data
                    n[y0:y1 + 1, x0:x1 + 1] = tile_cnt
                else:
                    self.log.debug(
                        'All pixels masked in tile lat {0}-{1}, lon {2}-{3}, map y {4}-{5}, map x {6}-{7}'.format(
                            tile_min_lat, tile_max_lat,
                            tile_min_lon, tile_max_lon,
                            y0, y1, x0, x1))

        # Store global map in a NetCDF file.
        # self._create_nc_file(a, 'tam.nc', 'val', fill=self._fill)

        # Create dict for JSON response
        results = [[{'maxima': a[y, x, 0], 'minima': a[y, x, 1], 'absolute_maxima': a[y, x, 2], 'absolute_minima': a[y, x, 3], 'cnt': int(n[y, x]),
                     'lat': self._ind2lat(y), 'lon': self._ind2lon(x)}
                    for x in range(a.shape[1])] for y in range(a.shape[0])]

        return NexusResults(results=results, meta={}, stats=None,
                            computeOptions=None, minLat=bbox.bounds[1],
                            maxLat=bbox.bounds[3], minLon=bbox.bounds[0],
                            maxLon=bbox.bounds[2], ds=ds, startTime=start_time,
                            endTime=end_time)