Add ee.Reducer.count examples.

PiperOrigin-RevId: 865445624

Author: schwehr

samples/javascript/apidocs/ee-reducer-count.js

@@ -0,0 +1,50 @@
+/**
+ * Copyright 2026 The Google Earth Engine Community Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// [START earthengine__apidocs__ee_reducer_count]
+print(ee.List([]).reduce(ee.Reducer.count()));  // 0
+print(ee.List([0]).reduce(ee.Reducer.count()));  // 1
+print(ee.List([-1]).reduce(ee.Reducer.count()));  // 1
+print(ee.List([1, null, 3]).reduce(ee.Reducer.count()));  // 2
+print(ee.List([1, '', 3]).reduce(ee.Reducer.count()));  // 3
+
+print(ee.Array([1, 0, 3]).reduce(ee.Reducer.count(), [0]));  // [3]
+
+var anArray = ee.Array([[1, 0, 3], [1, 2, 3]]);
+print(anArray.reduce(ee.Reducer.count(), [0]));  // [[2, 2, 2]]
+print(anArray.reduce(ee.Reducer.count(), [1]));  // [[3], [3]]
+print(anArray.reduce(ee.Reducer.count(), [1, 0]));  // [[6]]
+
+// Use reduceRegion to apply count().
+var elev = ee.Image('CGIAR/SRTM90_V4');
+var roi = ee.Geometry.Point([-119.86, 37.74]).buffer(5000);
+
+// Create a mask where elevation is greater than 2000 meters.
+var highElevMask = elev.gt(2000);
+
+// Update the image with the mask. Pixels = 0 in the mask become null/masked.
+var maskedElev = elev.updateMask(highElevMask);
+
+// Run the count reducer. Masked pixels are ignored.
+var highElevCount = maskedElev.reduceRegion({
+  reducer: ee.Reducer.count(),
+  geometry: roi,
+  scale: 90,
+  maxPixels: 1e9
+});
+
+print('Count of pixels > 2000m:', highElevCount.get('elevation'));  // 20
+// [END earthengine__apidocs__ee_reducer_count]

samples/python/apidocs/ee_reducer_count.py

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+# Copyright 2026 The Google Earth Engine Community Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# [START earthengine__apidocs__ee_reducer_count]
+display(ee.List([]).reduce(ee.Reducer.count()))  # 0
+display(ee.List([0]).reduce(ee.Reducer.count()))  # 1
+display(ee.List([-1]).reduce(ee.Reducer.count()))  # 1
+display(ee.List([1, None, 3]).reduce(ee.Reducer.count()))  # 2
+display(ee.List([1, '', 3]).reduce(ee.Reducer.count()))  # 3
+
+display(ee.Array([1, 0, 3]).reduce(ee.Reducer.count(), [0]))  # [3]
+
+an_array = ee.Array([[1, 0, 3], [1, 2, 3]])
+display(an_array.reduce(ee.Reducer.count(), [0]))  # [[2, 2, 2]]
+display(an_array.reduce(ee.Reducer.count(), [1]))  # [[3], [3]]
+display(an_array.reduce(ee.Reducer.count(), [1, 0]))  # [[6]]
+
+# Use reduceRegion to apply count().
+elev = ee.Image('CGIAR/SRTM90_V4')
+roi = ee.Geometry.Point([-119.86, 37.74]).buffer(5000)
+
+# Create a mask where elevation is greater than 2000 meters.
+high_elev_mask = elev.gt(2000)
+
+# Update the image with the mask. Pixels = 0 in the mask become null/masked.
+masked_elev = elev.updateMask(high_elev_mask)
+
+# Run the count reducer. Masked pixels are ignored.
+high_elev_count = masked_elev.reduceRegion(
+    reducer=ee.Reducer.count(),
+    geometry=roi,
+    scale=90,
+    maxPixels=int(1e9)
+)
+
+display('Count of pixels > 2000m:', high_elev_count.get('elevation'))  # 20
+# [END earthengine__apidocs__ee_reducer_count]