UPDATE-README

README.md

@@ -1,5 +1,5 @@
 # Magellan: Geospatial Analytics Using Spark
-
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@@ -167,6 +167,14 @@ A few common packages you might want to import within Magellan
 	| Point(1.0, -1.0)|Polygon(5, Vector...|
 	+-----------------+--------------------+
 
+### contains
+
+Since contains is an overloaded expression (contains is used for checking String containment by Spark SQL), Magellan uses the Binary Expression ```>?``` for checking shape containment.
+
+	points.join(polygons).where($"polygon" >? $"polygon").show()
+
+
+
 A Databricks notebook with similar examples is published [here](https://databricks-prod-cloudfront.cloud.databricks.com/public/4027ec902e239c93eaaa8714f173bcfc/137058993011870/882779309834027/6891974485343070/latest.html) for convenience.
 
 # Spatial indexes