Limited valuecount range to histogram range in aggregator.

Author: yellowcap

raster/valuecount.py

@@ -146,13 +146,20 @@ def _push_stats(self, data):
         if data.size == 0:
             return
 
+        # Filter data by histogram range.
+        if self.hist_range:
+            stats_data = data[data >= self.hist_range[0]]
+            stats_data = stats_data[stats_data <= self.hist_range[1]]
+        else:
+            stats_data = data
+
         # Compute incremental statistics
-        self._stats_t0 += data.size
-        self._stats_t1 += numpy.sum(data)
-        self._stats_t2 += numpy.sum(numpy.square(data))
+        self._stats_t0 += stats_data.size
+        self._stats_t1 += numpy.sum(stats_data)
+        self._stats_t2 += numpy.sum(numpy.square(stats_data))
 
-        tile_max = numpy.max(data)
-        tile_min = numpy.min(data)
+        tile_max = numpy.max(stats_data)
+        tile_min = numpy.min(stats_data)
 
         if self._stats_max_value is None:
             self._stats_max_value = tile_max

tests/test_valuecount.py

@@ -283,6 +283,37 @@ def test_histogram_range(self):
                 '(40.0, 50.0)': 0,
             }
         )
+        # Limit histogram range.
+        agg = Aggregator(
+            layer_dict={'a': self.rasterlayer.id},
+            formula='a',
+            grouping='continuous',
+            hist_range=(0.5, 8)
+        )
+        # Compute value count.
+        vals = agg.value_count()
+        self.assertDictEqual(
+            vals,
+            {
+                '(0.5, 1.25)': 695,
+                '(1.25, 2.0)': 0,
+                '(2.0, 2.75)': 56,
+                '(2.75, 3.5)': 4131,
+                '(3.5, 4.25)': 31490,
+                '(4.25, 5.0)': 0,
+                '(5.0, 5.75)': 0,
+                '(5.75, 6.5)': 0,
+                '(6.5, 7.25)': 0,
+                '(7.25, 8.0)': 1350
+            }
+        )
+        # Statistics are clipped to range.
+        self.assertEqual(agg._stats_min_value, 1)
+        self.assertEqual(agg._stats_max_value, 8)
+        self.assertEqual(agg._stats_t0, 37722)
+        self.assertEqual(sum(vals.values()), agg._stats_t0)
+        self.assertEqual(agg._stats_t1, 149960)
+        self.assertEqual(agg._stats_t2, 628338)
 
     def test_memory_efficient(self):
         agg = Aggregator(