Allow arithmetic operations with nils in data series

If a nil is present, we will keep a nil in the result.

Author: jecisc

src/DataFrame-Tests/DataSeriesTest.class.st

@@ -188,6 +188,17 @@ DataSeriesTest >> testArithmeticsDivideSeriesBySeriesSameKeysDifferentName [
 	self assert: actual equals: expected
 ]
 
+{ #category : #'as yet unclassified' }
+DataSeriesTest >> testArithmeticsDivideSeriesBySeriesWithNils [
+
+	| a b c |
+	a := #( 2 4 nil ) asDataSeries.
+	b := #( 1 nil 3 ) asDataSeries.
+	c := #( 2 nil nil ) asDataSeries.
+
+	self assert: a / b equals: c
+]
+
 { #category : #arithmetic }
 DataSeriesTest >> testArithmeticsMultiplyArrayBySeries [
 

src/DataFrame/DataSeries.class.st

@@ -92,10 +92,13 @@ DataSeries >> adaptToCollection: rcvr andSend: selector [
 	"If I am involved in arithmetic with another Collection, return a Collection of
 	the results of each element combined with the scalar in that expression."
 
-	(rcvr isSequenceable and: [ self isSequenceable ]) ifFalse:
-		[self error: 'Only sequenceable collections may be combined arithmetically'].
-	^ rcvr withSeries: self collect:
-		[:rcvrElement :myElement | rcvrElement perform: selector with: myElement]
+	(rcvr isSequenceable and: [ self isSequenceable ]) ifFalse: [ self error: 'Only sequenceable collections may be combined arithmetically' ].
+
+
+	^ rcvr withSeries: self collect: [ :rcvrElement :myElement |
+		  (rcvrElement isNil or: [ myElement isNil ])
+			  ifTrue: [ nil ]
+			  ifFalse: [ rcvrElement perform: selector with: myElement ] ]
 ]
 
 { #category : #converting }