Added #sortDescendingByRowNames with tests.

Author: Joshua-Dias-Barreto

src/DataFrame-Tests/DataFrameTest.class.st

@@ -5272,6 +5272,29 @@ DataFrameTest >> testSortDescendingByAll [
 	self assert: actual equals: expected
 ]
 
+{ #category : #tests }
+DataFrameTest >> testSortDescendingByRowNames [
+
+	| dataFrame expected sortedDF |
+	dataFrame := DataFrame withRows:
+		             #( #( 'CD' 3 2 ) 
+							 #( 'AC' 1 4 ) 
+							 #( 'DB' 2 4 )
+		                #( 'BA' 5 1 ) ).
+	dataFrame rowNames: #( 'CD' 'AC' 'DB' 'BA' ).
+
+	expected := DataFrame withRows:
+		            #( #( 'DB' 2 4 ) 
+							#( 'CD' 3 2 ) 
+							#( 'BA' 5 1 )
+		               #( 'AC' 1 4 ) ).
+	expected rowNames: #( 'DB' 'CD' 'BA' 'AC' ).
+
+	sortedDF := dataFrame sortDescendingByRowNames.
+
+	self assert: sortedDF equals: expected
+]
+
 { #category : #tests }
 DataFrameTest >> testToColumnApplyElementwise [
 

src/DataFrame/DataFrame.class.st

@@ -2516,6 +2516,13 @@ DataFrame >> sortDescendingByAll: arrayOfColumnNames [
 	^ self
 ]
 
+{ #category : #sorting }
+DataFrame >> sortDescendingByRowNames [
+	"Sorts the rows of the data frame based on the row names in ascending order"
+
+	self sortByRowNamesUsing: [ :a :b | a >= b ]
+]
+
 { #category : #statistics }
 DataFrame >> stdev [
 	"Standard deviation is a measure of how dispersed the data is in relation to the average"