docs

Author: Baunsgaard

src/main/java/org/apache/sysds/runtime/frame/data/columns/ACompressedArray.java

@@ -159,6 +159,11 @@ public void setM(Map<T, Integer> map, AMapToData m, int i) {
 		throw new NotImplementedException();
 	}
 
+	@Override
+	public void setM(Map<T, Integer> map, int si, AMapToData m, int i) {
+		throw new NotImplementedException();
+	}
+
 	@Override
 	protected void mergeRecodeMaps(Map<T, Integer> target, Map<T, Integer> from) {
 		throw new DMLCompressionException("Invalid to change sub compressed array");

src/main/java/org/apache/sysds/runtime/frame/data/columns/Array.java

@@ -103,7 +103,7 @@ public synchronized final Map<T, Integer> getRecodeMap(int estimate) {
 	 * column.
 	 * 
 	 * @param estimate the estimated number of unique.
-	 * @param pool An executor pool to be used for parallel execution
+	 * @param pool     An executor pool to be used for parallel execution
 	 * @return A recode map
 	 */
 	public synchronized final Map<T, Integer> getRecodeMap(int estimate, ExecutorService pool) {
@@ -986,10 +986,27 @@ public double[] minMax(int l, int u) {
 		return new double[] {min, max};
 	}
 
+	/**
+	 * Set the index i in the map given based on the mapping provided. The map should be guaranteed to contain all unique
+	 * values.
+	 * 
+	 * @param map Map containing all unique values of this array
+	 * @param m   The array mapping to set the value part of the Map<T,Integer> from
+	 * @param i   The index to set in m
+	 */
 	public void setM(Map<T, Integer> map, AMapToData m, int i) {
 		m.set(i, map.get(getInternal(i)).intValue() - 1);
 	}
 
+	/**
+	 * Set the index i in the map given based on the mapping provided. The map should be guaranteed to contain all unique
+	 * values except null. Therefore in case of null we set the provided si value.
+	 * 
+	 * @param map Map containing all unique values of this array
+	 * @param si  The default value to use in m if this Array contains null at index i
+	 * @param m   The array mapping to set the value part of the Map<T,Integer> from
+	 * @param i   The index to set in m
+	 */
 	public void setM(Map<T, Integer> map, int si, AMapToData m, int i) {
 		try {
 			final T v = getInternal(i);

src/main/java/org/apache/sysds/runtime/transform/encode/CompressedEncode.java

@@ -448,7 +448,7 @@ private <T> AMapToData createMappingAMapToData(Array<T> a, Map<T, Integer> map,
 				if(containsNull)
 					return createMappingAMapToDataWithNull(a, map, si, m, start, end);
 				else
-					return createMappingAMapToDataNoNull(a, map, si, m, start, end);
+					return createMappingAMapToDataNoNull(a, map,  m, start, end);
 
 			}));
 
@@ -459,7 +459,7 @@ private <T> AMapToData createMappingAMapToData(Array<T> a, Map<T, Integer> map,
 		return m;
 	}
 
-	private static <T> AMapToData createMappingAMapToDataNoNull(Array<T> a, Map<T, Integer> map, int si, AMapToData m,
+	private static <T> AMapToData createMappingAMapToDataNoNull(Array<T> a, Map<T, Integer> map, AMapToData m,
 		int start, int end) {
 		for(int i = start; i < end; i++)
 			a.setM(map, m, i);

src/main/java/org/apache/sysds/runtime/transform/encode/MultiColumnEncoder.java

@@ -714,7 +714,6 @@ private static ArrayList<int[]> outputMatrixPreProcessing(MatrixBlock output, Ca
 				}
 			}
 			else { // csr
-				final int size = (int) nnz;
 				// Manually fill the row pointers based on nnzs/row (= #cols in the input)
 				// Not using the set() methods to 1) avoid binary search and shifting,
 				// 2) reduce thread contentions on the arrays