#162 Add DataSetLoader to conveniently load data sets

src/main/java/utils/DataSetLoader.java

@@ -0,0 +1,54 @@
+package utils;
+
+import datastructs.maths.DenseMatrixSet;
+import datastructs.maths.RowBuilder;
+import datastructs.utils.RowType;
+import parallel.partitioners.MatrixRowPartitionPolicy;
+import parallel.partitioners.RangePartitioner;
+import tech.tablesaw.api.Table;
+import tech.tablesaw.columns.Column;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+public class DataSetLoader {
+
+    public static Pair<DenseMatrixSet<Double>, List<Integer>> loadIrisDataSet() throws IOException, IllegalArgumentException {
+
+        // load the data
+        Table dataSetTable = TableDataSetLoader.loadDataSet(new File("src/main/resources/datasets/iris_data.csv"));
+
+        List<Integer> labels = new ArrayList<>();
+
+        Column species  = dataSetTable.column("species");
+
+        for (int i = 0; i < species.size(); i++) {
+
+            String label = (String) species.get(i);
+
+            if(label.equals("Iris-setosa")){
+
+                labels.add(0);
+            }
+            else if(label.equals("Iris-versicolor")){
+
+                labels.add(1);
+            }
+            else if(label.equals("Iris-virginica")){
+
+                labels.add(2);
+            }
+            else{
+                throw new IllegalArgumentException("Unknown class");
+            }
+        }
+
+        Table reducedDataSet = dataSetTable.removeColumns("species").first(dataSetTable.rowCount());
+        DenseMatrixSet dataSet = new DenseMatrixSet(RowType.Type.VECTOR, new RowBuilder());
+        dataSet.initializeFrom(reducedDataSet);
+
+        return PairBuilder.makePair(dataSet, labels);
+    }
+}