Merge pull request #240 from olekscode/239-Add-argmax-to-DataSeries

Fixed #239. Implemented argmin and argmax for DataSeries

Author: olekscode

src/DataFrame-Tests/DataSeriesTest.class.st

@@ -17,6 +17,54 @@ DataSeriesTest >> setUp [
 	series := DataSeries withKeys: keyArray values: #( 3 7 6 20 8 9 8 10 15 13 16 ) name: 'ExampleSeries'
 ]
 
+{ #category : #'tests - statistics' }
+DataSeriesTest >> testArgmax [
+
+	| records |
+	
+	records := DataSeries
+		withKeys: #(2017 2018 2019 2020)
+		values: #(13 42 25 15).
+		
+	self assert: records argmax equals: 2018
+]
+
+{ #category : #'tests - statistics' }
+DataSeriesTest >> testArgmaxWithNils [
+
+	| records |
+	
+	records := DataSeries
+		withKeys: #(2017 2018 2019 2020)
+		values: #(13 nil 25 15).
+		
+	self assert: records argmax equals: 2019
+]
+
+{ #category : #'tests - statistics' }
+DataSeriesTest >> testArgmin [
+
+	| records |
+	
+	records := DataSeries
+		withKeys: #(2017 2018 2019 2020)
+		values: #(13 42 25 15).
+		
+	self assert: records argmin equals: 2017
+]
+
+{ #category : #'tests - statistics' }
+DataSeriesTest >> testArgminWithNils [
+
+	| records |
+	
+	records := DataSeries
+		withKeys: #(2017 2018 2019 2020)
+		values: #(nil 42 25 15).
+		
+	self assert: records argmin equals: 2020
+]
+
 { #category : #'tests - arithmetic' }
 DataSeriesTest >> testArithmeticsAddArrayToSeries [
 

src/DataFrame/DataSeries.class.st

@@ -111,6 +111,20 @@ DataSeries >> adaptToCollection: rcvr andSend: selector [
 			  ifFalse: [ rcvrElement perform: selector with: myElement ] ]
 ]
 
+{ #category : #statistics }
+DataSeries >> argmax [
+	"Returns the key which corresponds to the maximum value of the dataseries"
+
+	^ self keyAtValue: self max
+]
+
+{ #category : #statistics }
+DataSeries >> argmin [
+	"Returns the key which corresponds to the minimum value of the dataseries"
+
+	^ self keyAtValue: self min
+]
+
 { #category : #converting }
 DataSeries >> asDataFrame [
 	"Converts a data series to a data frame with 1 column. The values in the column of the data frame are the values of the data series. The row names of this data frame are the keys of the data series. The column name of the data frame is same as the name of the data series"