/**
* Strips the dataset down to the specified labels and remaps them
*
* @param labels the labels to strip down to
*/
public void filterAndStrip(int[] labels) {
FloatDataSet filtered = filterBy(labels);
List<Integer> newLabels = new ArrayList<>();
// map new labels to index according to passed in labels
Map<Integer, Integer> labelMap = new HashMap<>();
for (int i = 0; i < labels.length; i++) labelMap.put(labels[i], i);
// map examples
for (int i = 0; i < filtered.numExamples(); i++) {
int o2 = filtered.get(i).outcome();
int outcome = labelMap.get(o2);
newLabels.add(outcome);
}
FloatMatrix newLabelMatrix = new FloatMatrix(filtered.numExamples(), labels.length);
if (newLabelMatrix.rows != newLabels.size())
throw new IllegalStateException("Inconsistent label sizes");
for (int i = 0; i < newLabelMatrix.rows; i++) {
Integer i2 = newLabels.get(i);
if (i2 == null) throw new IllegalStateException("Label not found on row " + i);
FloatMatrix newRow = MatrixUtil.toOutcomeVectorFloat(i2, labels.length);
newLabelMatrix.putRow(i, newRow);
}
setFirst(filtered.getFirst());
setSecond(newLabelMatrix);
}
public void shuffle() {
List<FloatDataSet> list = asList();
Collections.shuffle(list);
FloatDataSet ret = FloatDataSet.merge(list);
setFirst(ret.getFirst());
setSecond(ret.getSecond());
}
/**
* Strips the data applyTransformToDestination of all but the passed in labels
*
* @param labels strips the data applyTransformToDestination of all but the passed in labels
* @return the dataset with only the specified labels
*/
public FloatDataSet filterBy(int[] labels) {
List<FloatDataSet> list = asList();
List<FloatDataSet> newList = new ArrayList<>();
List<Integer> labelList = new ArrayList<>();
for (int i : labels) labelList.add(i);
for (FloatDataSet d : list) {
if (labelList.contains(d.getLabel(d))) {
newList.add(d);
}
}
return FloatDataSet.merge(newList);
}
public static FloatDataSet merge(List<FloatDataSet> data) {
if (data.isEmpty()) throw new IllegalArgumentException("Unable to merge empty dataset");
FloatDataSet first = data.get(0);
int numExamples = totalExamples(data);
FloatMatrix in = new FloatMatrix(numExamples, first.getFirst().columns);
FloatMatrix out = new FloatMatrix(numExamples, first.getSecond().columns);
int count = 0;
for (int i = 0; i < data.size(); i++) {
FloatDataSet d1 = data.get(i);
for (int j = 0; j < d1.numExamples(); j++) {
FloatDataSet example = d1.get(j);
in.putRow(count, example.getFirst());
out.putRow(count, example.getSecond());
count++;
}
}
return new FloatDataSet(in, out);
}
private int getLabel(FloatDataSet data) {
return SimpleBlas.iamax(data.getSecond());
}
public void addRow(FloatDataSet d, int i) {
if (i > numExamples() || d == null)
throw new IllegalArgumentException("Invalid index for adding a row");
getFirst().putRow(i, d.getFirst());
getSecond().putRow(i, d.getSecond());
}
/**
* Partitions the data applyTransformToDestination by the specified number.
*
* @param num the number to split by
* @return the partitioned data applyTransformToDestination
*/
public List<FloatDataSet> dataSetBatches(int num) {
List<List<FloatDataSet>> list = Lists.partition(asList(), num);
List<FloatDataSet> ret = new ArrayList<>();
for (List<FloatDataSet> l : list) ret.add(FloatDataSet.merge(l));
return ret;
}
private static int totalExamples(Collection<FloatDataSet> coll) {
int count = 0;
for (FloatDataSet d : coll) count += d.numExamples();
return count;
}