Added Sum resampling method

Signed-off-by: Christos <xr_xarmatzis@outlook.com>
locationtech · Aug 11, 2017 · 8a69298 · 8a69298
1 parent 44b5535
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diff --git a/raster-test/src/test/scala/geotrellis/raster/resample/SumResampleSpec.scala b/raster-test/src/test/scala/geotrellis/raster/resample/SumResampleSpec.scala
@@ -0,0 +1,76 @@
+/*
+ * Copyright 2016 Azavea
+ *
+ * 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
+ *
+ *     http://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.
+ */
+
+package geotrellis.raster.resample
+
+import geotrellis.raster._
+import geotrellis.vector.Extent
+
+import org.scalatest._
+
+class SumResampleSpec extends FunSpec with Matchers {
+
+  describe("it should resample to nodata when only nodata in tile") {
+
+    it("should for a nodata integer tile compute nodata as sum value") {
+      val tile = IntArrayTile(Array(NODATA, NODATA, NODATA,
+        NODATA, NODATA, NODATA,
+        NODATA, NODATA, NODATA), 3, 3)
+      val extent = Extent(0, 0, 10, 10)
+      val cellsize = CellSize(extent, 10, 10)
+      tile.resample(extent, 1, 1, Sum).get(0, 0) should be (NODATA)
+    }
+
+    it("should for a nodata double tile compute nodata as sum value") {
+      val tile = DoubleArrayTile(Array(NODATA, NODATA, NODATA,
+        NODATA, NODATA, NODATA,
+        NODATA, NODATA, NODATA), 3, 3)
+      val extent = Extent(0, 0, 10, 10)
+      val cellsize = CellSize(extent, 10, 10)
+      tile.resample(extent, 1, 1, Sum).get(0, 0) should be (NODATA)
+    }
+
+    it("should for an integer tile compute the correct sum value") {
+      val tile = ArrayTile(Array(1, 1, 1, 1, 1, 1, 1, 1, 1), 3, 3)
+      val extent = Extent(0, 0, 3, 3)
+      val cellsize = CellSize(extent, 3, 3)
+      tile.resample(extent, 1, 1, Sum).get(0, 0) should be (9)
+    }
+
+    it("should for a int tile compute the correct sum value - ignoring the nodata value") {
+      val tile = ArrayTile(Array(NODATA, 1, 1, 1, 1, 1, 1, 1, 1), 3, 3)
+      val extent = Extent(0, 0, 3, 3)
+      val cellsize = CellSize(extent, 3, 3)
+      tile.resample(extent, 1, 1, Sum).get(0, 0) should be (8)
+    }
+
+
+    it("should for a double tile compute the correct sum value") {
+      val tile = DoubleArrayTile(Array(.1, .1, .1, .1, .1, .1, .1, .1, .1), 3, 3)
+      val extent = Extent(0, 0, 3, 3)
+      val cellsize = CellSize(extent, 3, 3)
+      tile.resample(extent, 1, 1, Sum).getDouble(0, 0) should be (0.9 +- 0.01)
+    }
+
+    // This test is necessitated because of Double.NaN's always being max and min according to scala
+    it("should for a double tile compute the correct sum value - ignoring the nodata value") {
+      val tile = DoubleArrayTile(Array(Double.NaN, .1, .1, .1, .1, .1, .1, .1, .1), 3, 3)
+      val extent = Extent(0, 0, 3, 3)
+      val cellsize = CellSize(extent, 3, 3)
+      tile.resample(extent, 1, 1, Sum).getDouble(0, 0) should be (0.8 +- 0.01)
+    }
+  }
+}
diff --git a/raster/src/main/scala/geotrellis/raster/resample/Resample.scala b/raster/src/main/scala/geotrellis/raster/resample/Resample.scala
@@ -17,7 +17,7 @@
 package geotrellis.raster.resample
 
 import geotrellis.raster._
-import geotrellis.vector.{Point, Extent}
+import geotrellis.vector.{Extent, Point}
 
 sealed trait ResampleMethod
 
@@ -34,6 +34,7 @@ case object Mode    extends AggregateResampleMethod
 case object Median    extends AggregateResampleMethod
 case object Max    extends AggregateResampleMethod
 case object Min    extends AggregateResampleMethod
+case object Sum extends AggregateResampleMethod
 
 object ResampleMethod {
   val DEFAULT: PointResampleMethod = NearestNeighbor
@@ -110,5 +111,6 @@ object Resample {
       case Median => new MedianResample(tile, extent, cs)
       case Max => new MaxResample(tile, extent, cs)
       case Min => new MinResample(tile, extent, cs)
+      case Sum =>  new SumResample(tile, extent, cs)
     }
 }
diff --git a/raster/src/main/scala/geotrellis/raster/resample/SumResample.scala b/raster/src/main/scala/geotrellis/raster/resample/SumResample.scala
@@ -0,0 +1,51 @@
+/*
+ * Copyright 2016 Azavea
+ *
+ * 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
+ *
+ *     http://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.
+ */
+
+package geotrellis.raster.resample
+
+import geotrellis.raster._
+import geotrellis.vector.Extent
+
+class SumResample (tile: Tile, extent: Extent, targetCS: CellSize)
+  extends AggregateResample(tile, extent, targetCS) {
+
+  private def calculateMax(indices: Seq[(Int, Int)]): Int = {
+    val (sum, count) =
+      indices.foldLeft((0, 0)) { case ((sum, count), coords) =>
+        val v = tile.get(coords._1, coords._2)
+        if (isData(v)) (sum + v, count + 1)
+        else (sum, count)
+      }
+    if (count > 0) sum  else Int.MinValue
+  }
+
+
+  private def calculateMaxDouble(indices: Seq[(Int, Int)]): Double = {
+    val (sum, count) =
+      indices.foldLeft((0.0, 0)) { case ((sum, count), coords) =>
+        val v = tile.getDouble(coords._1, coords._2)
+        if (isData(v)) (sum + v, count + 1)
+        else (sum, count)
+      }
+    if (count > 0) sum  else Double.NaN
+  }
+
+
+  def resampleValid(x: Double, y: Double): Int = calculateMax(contributions(x, y))
+
+  def resampleDoubleValid(x: Double, y: Double): Double = calculateMaxDouble(contributions(x,y))
+
+}