updated logic for checking empty band to exclude masked areas

databrickslabs · Feb 13, 2024 · 6a79482 · 6a79482
1 parent 9043e03
commit 6a79482
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Showing 3 changed files with 6 additions and 7 deletions.
diff --git a/python/test/test_raster_functions.py b/python/test/test_raster_functions.py
@@ -115,7 +115,7 @@ def test_raster_flatmap_functions(self):
         )
 
         tessellate_result.write.format("noop").mode("overwrite").save()
-        self.assertEqual(tessellate_result.count(), 140)
+        self.assertEqual(tessellate_result.count(), 66)
 
         overlap_result = (
             self.generate_singleband_raster_df()
@@ -127,7 +127,7 @@ def test_raster_flatmap_functions(self):
         )
 
         overlap_result.write.format("noop").mode("overwrite").save()
-        self.assertEqual(overlap_result.count(), 196)
+        self.assertEqual(overlap_result.count(), 87)
 
     def test_raster_aggregator_functions(self):
         collection = (

diff --git a/src/main/scala/com/databricks/labs/mosaic/core/raster/gdal/MosaicRasterBandGDAL.scala b/src/main/scala/com/databricks/labs/mosaic/core/raster/gdal/MosaicRasterBandGDAL.scala
@@ -236,9 +236,8 @@ case class MosaicRasterBandGDAL(band: Band, id: Int) {
       *   Returns true if the band is empty.
       */
     def isEmpty: Boolean = {
-        val minMaxVals = Array.fill[Double](2)(0)
-        band.ComputeRasterMinMax(minMaxVals, 0)
-        minMaxVals.head == minMaxVals.last && minMaxVals.head == noDataValue
+        val stats = band.AsMDArray().GetStatistics()
+        stats.getValid_count == 0
     }
 
 }
diff --git a/src/test/scala/com/databricks/labs/mosaic/expressions/raster/RST_TessellateBehaviors.scala b/src/test/scala/com/databricks/labs/mosaic/expressions/raster/RST_TessellateBehaviors.scala
@@ -40,7 +40,7 @@ trait RST_TessellateBehaviors extends QueryTest {
 
         val result = gridTiles.collect()
 
-        result.length should be(980)
+        result.length should be(462)
 
         val netcdf = spark.read
             .format("gdal")
@@ -55,7 +55,7 @@ trait RST_TessellateBehaviors extends QueryTest {
 
         val netcdfResult = netcdfGridTiles.collect()
 
-        netcdfResult.length should be(842)
+        netcdfResult.length should be(491)
 
     }