Closed #88. Fixed a bug in DataSeries >> quantile:

Author: olekscode

src/DataFrame-Tests/DataSeriesTest.class.st

@@ -1331,6 +1331,15 @@ DataSeriesTest >> testStatsQuantile [
 	self assert: (series quantile: 100) equals: 20.
 ]
 
+{ #category : #tests }
+DataSeriesTest >> testStatsQuantileDoesNotModifyTheSeries [
+	
+	| copy |
+	copy := series copy.
+	series quantile: 5.
+	self assert: series equals: copy.
+]
+
 { #category : #tests }
 DataSeriesTest >> testStatsQuartile [
 

src/DataFrame/DataSeries.class.st

@@ -324,7 +324,7 @@ DataSeries >> ninth [
 { #category : #statistics }
 DataSeries >> quantile: aNumber [
 	| sortedSeries index |
-	sortedSeries := self sort.
+	sortedSeries := self sorted.
 
 	aNumber = 0
 		ifTrue: [ ^ sortedSeries first ].