Adding DFLib Java DataFrame to comparison

build.gradle

@@ -13,7 +13,7 @@ apply plugin: 'java'
 apply plugin: 'kotlin'
 apply plugin: 'eclipse'
 
-sourceCompatibility = 1.8
+sourceCompatibility = 11
 
 repositories {
   mavenCentral()
@@ -39,5 +39,7 @@ dependencies {
 
   implementation "org.jetbrains.kotlinx:dataframe:0.10.0"
   implementation 'org.duckdb:duckdb_jdbc:0.8.0'
+
+  implementation 'org.dflib:dflib-csv:1.1.0'
 }
 

src/main/java/test_dataframes/TestDFLib.java

@@ -0,0 +1,69 @@
+package test_dataframes;
+
+import com.google.common.base.Stopwatch;
+import org.apache.commons.csv.CSVFormat;
+import org.dflib.DataFrame;
+import org.dflib.Printers;
+import org.dflib.ValueMapper;
+import org.dflib.csv.Csv;
+import org.dflib.print.Printer;
+
+import static org.dflib.Exp.*;
+
+/**
+ * Test the API of tablesaw to do some basic dataframe manipulations.
+ * <p>
+ * https://github.com/dflib/dflib
+ * <p>
+ * See https://medium.com/@thijser/doing-cool-data-science-in-java-how-3-dataframe-libraries-stack-up-5e6ccb7b437
+ * for more information.
+ */
+public class TestDFLib {
+    public static void main(String[] args) {
+
+        Printer printer = Printers.tabular(10, 100);
+
+        DataFrame data = Csv.loader()
+                .format(CSVFormat.DEFAULT.builder().setNullString(":").build())
+                .col("Value", ValueMapper.stringToInt())
+                .load("urb_cpop1_1_Data.csv");
+        System.out.println(printer.toString(data));
+
+        Stopwatch watch = Stopwatch.createStarted();
+        DataFrame filtered = data.rows($col("Value").isNotNull()).select();
+
+        DataFrame cities = filtered.group("CITIES", "INDIC_UR", "TIME")
+                .cols("CITIES", "INDIC_UR", "TIME", "Mean [Value]")
+                .agg($col("CITIES"), $col("INDIC_UR"), $col("TIME"), $int("Value").avg().castAsInt());
+
+        System.out.println(printer.toString(cities));
+
+        // Need to transpose/pivot now too
+        DataFrame finalTable = cities
+                .cols("key").merge(concat($str("CITIES"), ":", $str("INDIC_UR")))
+                .pivot().rows("key").cols("TIME").vals("Mean [Value]");
+
+        // sortDescendingOn puts N/A values first unfortunately, so let's remove them
+        // before determining and printing.
+        DataFrame existing2017 = finalTable
+                .rowsExcept($int("2017").isNull()).select()
+                .rows($str("key").endsWith("January, total")).select()
+                .sort($int("2017").desc());
+        System.out.println(printer.toString(existing2017));
+
+        // Add growth column
+
+        DataFrame finalTable1 = finalTable
+                .cols("growth").merge($int("2016").castAsDouble().div($int("2010")).sub(1).mul(100));
+
+        DataFrame highestGrowthTable = finalTable1
+                .rows($str("key").endsWith("January, total")).select()
+                .rowsExcept($col("growth").isNull()).select()
+                .sort($double("growth").desc());
+
+        System.out.println(printer.toString(highestGrowthTable));
+        CheckResult.checkResult(highestGrowthTable.getColumn("key").toList());
+
+        System.out.println("Total time: " + watch);
+    }
+}