iGN5117 commented on code in PR #1038:
URL: https://github.com/apache/sedona/pull/1038#discussion_r1341825710
##########
docs/api/sql/Raster-operators.md:
##########
@@ -1004,6 +1004,105 @@ Output:
```
4
```
+### RS_Resample
+
+Introduction:
+Resamples a raster using a given resampling algorithm and new dimensions
(width and height), a new grid corner to pivot the raster at (gridX and gridY)
and a set of
+georeferencing attributes (scaleX and scaleY).
+
+RS_Resample also provides an option to pass a reference raster to draw the
georeferencing attributes out of. However, the SRIDs of the input and reference
raster must be same, otherwise RS_Resample throws an IllegalArgumentException.
+
+For the purpose of resampling, width-height pair and scaleX-scaleY pair are
mutually exclusive, meaning any one of them can be used at a time.
+
+The `useScale` parameter controls whether to use width-height or
scaleX-scaleY. If `useScale` is false, the provided `widthOrScale` and
`heightOrScale` values will be floored to integers and considered as width and
height respectively (floating point width and height are not allowed).
Otherwise, they are considered as scaleX and scaleY respectively.
+
+Currently, RS_Resample does not support skewed rasters, and hence even if a
skewed reference raster is provided, its skew values are ignored. If the input
raster is skewed, the output raster geometry and interpolation may be
incorrect.
+
+The default algorithm used for resampling is `NearestNeighbor`, and hence if a
null, empty or invalid value of algorithm is provided, RS_Resample defaults to
using `NearestNeighbor`. However, the algorithm parameter is non-optional.
+
+Following are valid values for the algorithm parameter (Case-insensitive):
+
+1. NearestNeighbor
+2. Bilinear
+3. Bicubic
+
+!!!Tip
+ If you just want to resize or rescale an input raster, you can use
RS_Resample(raster: Raster, widthOrScale: Double, heightOrScale: Double,
useScale: Boolean, algorithm: String)
+Format:
+
+```sql
+RS_Resample(raster: Raster, widthOrScale: Double, heightOrScale: Double,
gridX: Double, gridY: Double, useScale: Boolean, algorithm: String)
+```
+
+```sql
+RS_Resample(raster: Raster, widthOrScale: Double, heightOrScale: Double,
useScale: Boolean, algorithm: String)
+```
+
+```sql
+RS_Resample(raster: Raster, referenceRaster: Raster, useScale: Boolean,
algorithm: String)
+```
+
+Since: `v1.5.0`
+
+Spark SQL Example:
+
+```scala
+val inputDf = Seq(Seq(1, 2, 3, 5, 4, 5, 6, 9, 7, 8, 9, 10)).toDF("band")
+val df = inputDf.selectExpr("RS_AddBandFromArray(RS_MakeEmptyRaster(1, 'd', 4,
3, 0, 0, 2, -2, 0, 0, 0), band, 1, 0d) as raster")
+val rasterDf = df.selectExpr("RS_Resample(raster, 6, 5, 1, -1, false, null) as
raster")
+val rasterOutput =
rasterDf.selectExpr("RS_AsMatrix(raster)").first().getString(0)
+val rasterMetadata =
rasterDf.selectExpr("RS_Metadata(raster)").first().getSeq[Double](0)
+```
+
+`Output`:
+```sql
+| 1.0 1.0 2.0 3.0 3.0 5.0|
+| 1.0 1.0 2.0 3.0 3.0 5.0|
+| 4.0 4.0 5.0 6.0 6.0 9.0|
+| 7.0 7.0 8.0 9.0 9.0 10.0|
+| 7.0 7.0 8.0 9.0 9.0 10.0|
+
+(-0.33333333333333326,0.19999999999999996,6,5,1.388888888888889,-1.24,0,0,0,1)
+```
+
+```scala
+val inputDf = Seq(Seq(1, 2, 3, 5, 4, 5, 6, 9, 7, 8, 9, 10)).toDF("band")
Review Comment:
Done
##########
spark/common/src/test/scala/org/apache/sedona/sql/rasteralgebraTest.scala:
##########
@@ -1077,6 +1077,7 @@ class rasteralgebraTest extends TestBaseScala with
BeforeAndAfter with GivenWhen
val df = inputDf.selectExpr("RS_AddBandFromArray(RS_MakeEmptyRaster(1,
4, 3, 0, 0, 1, -1, 0, 0, 0), band, 1, 0d) as emptyRaster")
val resultDf = df.selectExpr("RS_AsMatrix(emptyRaster, 1, 5) as matrix")
val actual = resultDf.first().getString(0);
+ resultDf.show()
Review Comment:
Done
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