Add ability to load gziped CSV files

src/main/java/ca/joeltherrien/randomforest/DataLoader.java

@@ -12,6 +12,7 @@ import org.apache.commons.csv.CSVRecord;
 
 import java.io.*;
 import java.util.*;
+import java.util.zip.GZIPInputStream;
 
 public class DataLoader {
 
@@ -19,7 +20,18 @@ public class DataLoader {
 
         final List<Row<Y>> dataset = new ArrayList<>();
 
-        final Reader input = new FileReader(filename);
+        final Reader input;
+        if(filename.endsWith(".gz")){
+            final FileInputStream inputStream = new FileInputStream(filename);
+            final GZIPInputStream gzipInputStream = new GZIPInputStream(inputStream);
+
+            input = new InputStreamReader(gzipInputStream);
+        }
+        else{
+            input = new FileReader(filename);
+        }
+
+
         final CSVParser parser = CSVFormat.RFC4180.withFirstRecordAsHeader().parse(input);
 
 

src/test/java/ca/joeltherrien/randomforest/csv/TestLoadingCSV.java

@@ -28,14 +28,14 @@ public class TestLoadingCSV {
         -3,NA,NA,NA
      */
 
-    @Test
+
-    public void verifyLoading() throws IOException, ClassNotFoundException {
+    public List<Row<Double>> loadData(String filename) throws IOException {
         final ObjectNode yVarSettings = new ObjectNode(JsonNodeFactory.instance);
         yVarSettings.set("type", new TextNode("Double"));
         yVarSettings.set("name", new TextNode("y"));
 
         final Settings settings = Settings.builder()
-                .dataFileLocation("src/test/resources/testCSV.csv")
+                .dataFileLocation(filename)
                 .covariates(
                         List.of(new NumericCovariateSettings("x1"),
                                 new FactorCovariateSettings("x2", List.of("dog", "cat", "mouse")),
@@ -52,6 +52,25 @@ public class TestLoadingCSV {
 
         final List<Row<Double>> data = DataLoader.loadData(covariates, loader, settings.getDataFileLocation());
 
+        return data;
+    }
+
+    @Test
+    public void verifyLoadingNormal() throws IOException {
+        final List<Row<Double>> data = loadData("src/test/resources/testCSV.csv");
+
+        assertData(data);
+    }
+
+    @Test
+    public void verifyLoadingGz() throws IOException {
+        final List<Row<Double>> data = loadData("src/test/resources/testCSV.csv.gz");
+
+        assertData(data);
+    }
+
+
+    private void assertData(final List<Row<Double>> data){
         assertEquals(4, data.size());
 
         Row<Double> row = data.get(0);
@@ -77,7 +96,6 @@ public class TestLoadingCSV {
         assertEquals(true, row.getCovariateValue("x1").isNA());
         assertEquals(true, row.getCovariateValue("x2").isNA());
         assertEquals(true, row.getCovariateValue("x3").isNA());
-
     }
 
 }