Alternative optimized version

Author: stelliom

python/extpar_art_to_buffer.py

@@ -106,6 +106,33 @@ def get_fraction_per_soil_type(soil_id):
     return soil_fractions_target
 
 
+def calculate_soil_fraction_optimized(target_grid, soil_types_raw, nearest_target_cell_to_raw_cells, ncpu=13):
+    """
+    target_grid: target ICON grid
+    soil_types_raw: landuse class for each cell from the HWSD dataset (LU variable)
+    nearest_target_cell_to_raw_cell: indices of the cell from the target ICON grid which is nearest to each cell of the raw grid (from HWSD dataset)
+    """
+    ncells_target = target_grid.lons.size
+    nsoil_types = 13
+    nthreads = min(nsoil_types, ncpu)
+
+    soil_fractions_target = np.zeros((ncells_target, nsoil_types))
+
+    n_nearest_raw_cells = np.bincount(nearest_target_cell_to_raw_cells.ravel(),
+                                      minlength=ncells_target)
+
+    valid_mask = (soil_types_raw >= 1) & (soil_types_raw <= nsoil_types)
+    counts = np.zeros((ncells_target, nsoil_types), dtype=int)
+    np.add.at(counts, (nearest_target_cell_to_raw_cells[valid_mask], soil_types_raw[valid_mask].astype(int)-1), 1)
+
+    np.divide(counts,
+              n_nearest_raw_cells[:, np.newaxis],
+              out=soil_fractions_target,
+              where=n_nearest_raw_cells[:, np.newaxis] != 0)
+
+    return soil_fractions_target
+
+
 # --------------------------------------------------------------------------
 # --------------------------------------------------------------------------
 # initialize logger