public void SplitForCrossValidation(int numFolds, int fold, out LabeledDataset <LblT, ExT> trainSet, out LabeledDataset <LblT, ExT> testSet)
{
Utils.ThrowException(mItems.Count < 2 ? new InvalidOperationException() : null);
Utils.ThrowException((numFolds <2 || numFolds> mItems.Count) ? new ArgumentOutOfRangeException("numFolds") : null);
Utils.ThrowException((fold <1 || fold> numFolds) ? new ArgumentOutOfRangeException("fold") : null);
trainSet = new LabeledDataset <LblT, ExT>();
testSet = new LabeledDataset <LblT, ExT>();
double step = (double)mItems.Count / (double)numFolds;
double d = 0;
for (int i = 0; i < numFolds; i++, d += step)
{
int endJ = (int)Math.Round(d + step);
if (i == fold - 1)
{
for (int j = (int)Math.Round(d); j < endJ; j++)
{
testSet.Add(mItems[j].Label, mItems[j].Example);
}
}
else
{
for (int j = (int)Math.Round(d); j < endJ; j++)
{
trainSet.Add(mItems[j].Label, mItems[j].Example);
}
}
}
}
public static LabeledDataset <int, SparseVector <double> > LoadDataset(StreamReader reader)
{
Utils.ThrowException(reader == null ? new ArgumentNullException("reader") : null);
string line;
LabeledDataset <int, SparseVector <double> > dataset = new LabeledDataset <int, SparseVector <double> >();
while ((line = reader.ReadLine()) != null)
{
if (!line.StartsWith("#"))
{
Match labelMatch = new Regex(@"^(?<label>[+-]?\d+(\.\d+)?)(\s|$)").Match(line);
Utils.ThrowException(!labelMatch.Success ? new IOException() : null);
int label = Convert.ToInt32(labelMatch.Result("${label}"));
Match match = new Regex(@"(?<feature>\d+):(?<weight>[-]?[\d\.]+)").Match(line);
SparseVector <double> vec = new SparseVector <double>();
while (match.Success)
{
int feature = Convert.ToInt32(match.Result("${feature}"));
double weight = Convert.ToDouble(match.Result("${weight}"), CultureInfo.InvariantCulture);
match = match.NextMatch();
vec[feature] = weight;
}
dataset.Add(new LabeledExample <int, SparseVector <double> >(label, vec));
}
}
return(dataset);
}
public LabeledDataset <Cluster, ExT> GetClassificationDataset <ExT>(IUnlabeledExampleCollection <ExT> dataset)
{
Utils.ThrowException(dataset == null ? new ArgumentNullException("dataset") : null);
LabeledDataset <Cluster, ExT> classificationDataset = new LabeledDataset <Cluster, ExT>();
FillClassificationDataset(mRoots, dataset, classificationDataset); // throws ArgumentValueException
return(classificationDataset);
}
public static LabeledDataset <int, SparseVector <double> > LoadDataset(string fileName)
{
Utils.ThrowException(fileName == null ? new ArgumentNullException("fileName") : null);
Utils.ThrowException(!Utils.VerifyFileNameOpen(fileName) ? new ArgumentValueException("fileName") : null);
StreamReader reader = new StreamReader(fileName);
LabeledDataset <int, SparseVector <double> > dataset = LoadDataset(reader);
reader.Close();
return(dataset);
}
public ILabeledDataset <LblT> ConvertDataset(Type newExType, bool move)
{
Utils.ThrowException(newExType == null ? new ArgumentNullException("newExType") : null);
ILabeledDataset <LblT> newDataset = null;
ArrayList <LabeledExample <LblT, object> > tmp = new ArrayList <LabeledExample <LblT, object> >(mItems.Count);
for (int i = 0; i < mItems.Count; i++)
{
tmp.Add(new LabeledExample <LblT, object>(mItems[i].Label, ModelUtils.ConvertExample(mItems[i].Example, newExType))); // throws ArgumentValueException
if (move)
{
mItems[i] = null;
}
}
if (move)
{
mItems.Clear();
}
if (newExType == typeof(SparseVector <double>))
{
newDataset = new LabeledDataset <LblT, SparseVector <double> >(tmp);
}
else if (newExType == typeof(SparseVector <double> .ReadOnly))
{
newDataset = new LabeledDataset <LblT, SparseVector <double> .ReadOnly>(tmp);
}
else if (newExType == typeof(BinaryVector))
{
newDataset = new LabeledDataset <LblT, BinaryVector>(tmp);
}
else if (newExType == typeof(BinaryVector.ReadOnly))
{
newDataset = new LabeledDataset <LblT, BinaryVector.ReadOnly>(tmp);
}
else
{
throw new ArgumentNotSupportedException("newExType");
}
return(newDataset);
}
public UnlabeledDatasetEnumerator(LabeledDataset <LblT, ExT> dataset)
{
Utils.ThrowException(dataset == null ? new ArgumentNullException("dataset") : null);
mDataset = dataset;
}
public void SplitForStratifiedCrossValidation(int numFolds, int fold, out LabeledDataset <LblT, ExT> trainSet, out LabeledDataset <LblT, ExT> testSet)
{
Utils.ThrowException(mItems.Count < 2 ? new InvalidOperationException() : null);
Utils.ThrowException((numFolds <2 || numFolds> mItems.Count) ? new ArgumentOutOfRangeException("numFolds") : null);
Utils.ThrowException((fold <1 || fold> numFolds) ? new ArgumentOutOfRangeException("fold") : null);
// calc label segments
var labelSegments = new List <Pair <LblT, int> >();
LblT label = default(LblT);
for (int i = 0, startN = 0;; i++)
{
if (i > 0 && (i == mItems.Count || !label.Equals(mItems[i].Label)))
{
Utils.ThrowException(labelSegments.Any(p => p.First.Equals(label)) ? new InvalidOperationException("items not sorted") : null);
labelSegments.Add(new Pair <LblT, int>(label, i - startN));
startN = i;
}
if (i == mItems.Count)
{
break;
}
label = mItems[i].Label;
}
Utils.ThrowException(mItems.Count < numFolds * labelSegments.Count ? new ArgumentException("dataset too small to stratify") : null);
// populate sets
trainSet = new LabeledDataset <LblT, ExT>();
testSet = new LabeledDataset <LblT, ExT>();
int segStart = 0;
foreach (Pair <LblT, int> segment in labelSegments)
{
int len = segment.Second / numFolds;
int testStart = segStart + (fold - 1) * len;
int mod = segment.Second % numFolds;
if (fold <= mod)
{
len++; testStart += fold - 1;
}
else
{
testStart += mod;
}
int testEnd = testStart + len;
for (int i = segStart; i < testStart; i++)
{
trainSet.Add(mItems[i].Label, mItems[i].Example);
}
for (int i = testStart; i < testEnd; i++)
{
testSet.Add(mItems[i].Label, mItems[i].Example);
}
int segEnd = segStart + segment.Second;
for (int i = testEnd; i < segEnd; i++)
{
trainSet.Add(mItems[i].Label, mItems[i].Example);
}
segStart = segEnd;
}
}
private void FillClassificationDataset <ExT>(IEnumerable <Cluster> clusters, IUnlabeledExampleCollection <ExT> dataset, LabeledDataset <Cluster, ExT> classificationDataset)
{
foreach (Cluster cluster in clusters)
{
foreach (int item in cluster.Items)
{
Utils.ThrowException(item < 0 || item >= dataset.Count ? new ArgumentValueException("clusters") : null);
classificationDataset.Add(cluster, dataset[item]);
}
FillClassificationDataset(cluster.Children, dataset, classificationDataset);
}
}
