public static double TrimmedVariance(IDictionary <string, double[]> scoresByChr, double trim = 0.025)
{
int n = 0;
foreach (string chr in scoresByChr.Keys)
{
n += scoresByChr[chr].Length;
}
double[] diff = new double[n - 1];
int i = 0;
double last = Double.NaN;
foreach (string chr in scoresByChr.Keys)
{
if (scoresByChr[chr].Length <= 0)
{
continue;
}
if (i > 0)
{
diff[i] = scoresByChr[chr][0] - last;
i++;
}
Array.Copy(Helper.Diff(scoresByChr[chr]), 0, diff, i, scoresByChr[chr].Length - 1);
i += (scoresByChr[chr].Length - 1);
last = scoresByChr[chr][scoresByChr[chr].Length - 1];
}
int nKeep = Convert.ToInt32(Math.Round((1 - 2 * trim) * (n - 1)));
// R code: inflfact(trim)*sum((sort(abs(diff(genomdat)))[1:n.keep])^2 / (2*n.keep))
Helper.InplaceAbs(diff);
Array.Sort(diff);
return(ChangePoint.InflationFactor(trim) * Helper.PartialSumOfPowers(diff, 2, 0, nKeep) / (2 * nKeep));
}
/// <summary>
/// CBS: circular binary segmentation porting the R function segment in DNAcopy
/// </summary>
/// <param name="alpha">Now in this.Alpha</param>
/// <param name="nPerm"></param>
/// <param name="pMethod">"hybrid" or "perm"</param>
/// <param name="minWidth"></param>
/// <param name="kMax"></param>
/// <param name="nMin"></param>
/// <param name="eta"></param>
/// <param name="sbdry"></param>
/// <param name="trim"></param>
/// <param name="undoSplit">"none" or "prune" or "sdundo"; now in this.UndoMethod</param>
/// <param name="undoPrune"></param>
/// <param name="undoSD"></param>
/// <param name="verbose"></param>
public Dictionary <string, Segmentation.Segment[]> Run(Segmentation segmentation, uint nPerm = 10000, string pMethod = "hybrid", int minWidth = 2, int kMax = 25,
uint nMin = 200, double eta = 0.05, uint[] sbdry = null, double trim = 0.025,
double undoPrune = 0.05, double undoSD = 3, int verbose = 1)
{
if (minWidth < 2 || minWidth > 5)
{
Console.Error.WriteLine("Minimum segment width should be between 2 and 5");
Environment.Exit(1);
}
if (nMin < 4 * kMax)
{
Console.Error.WriteLine("nMin should be >= 4 * kMax");
Environment.Exit(1);
}
if (sbdry == null)
{
GetBoundary.ComputeBoundary(nPerm, this._alpha, eta, out sbdry);
}
Dictionary <string, int[]> inaByChr = new Dictionary <string, int[]>();
Dictionary <string, double[]> finiteScoresByChr = new Dictionary <string, double[]>();
List <ThreadStart> tasks = new List <ThreadStart>();
foreach (KeyValuePair <string, double[]> scoreByChrKVP in segmentation.ScoreByChr)
{
tasks.Add(new ThreadStart(() =>
{
string chr = scoreByChrKVP.Key;
int[] ina;
Helper.GetFiniteIndices(scoreByChrKVP.Value, out ina); // not NaN, -Inf, Inf
double[] scores;
if (ina.Length == scoreByChrKVP.Value.Length)
{
scores = scoreByChrKVP.Value;
}
else
{
Helper.ExtractValues <double>(scoreByChrKVP.Value, ina, out scores);
}
lock (finiteScoresByChr)
{
finiteScoresByChr[chr] = scores;
inaByChr[chr] = ina;
}
}));
}
Parallel.ForEach(tasks, task => task.Invoke());
// Quick sanity-check: If we don't have any segments, then return a dummy result.
int n = 0;
foreach (var list in finiteScoresByChr.Values)
{
n += list.Length;
}
if (n == 0)
{
return(new Dictionary <string, Segmentation.Segment[]>());
}
double trimmedSD = Math.Sqrt(ChangePoint.TrimmedVariance(finiteScoresByChr, trim: trim));
Dictionary <string, Segmentation.Segment[]> segmentByChr = new Dictionary <string, Segmentation.Segment[]>();
// when parallelizing we need an RNG for each chromosome to get deterministic results
Random seedGenerator = new MersenneTwister(0);
Dictionary <string, Random> perChromosomeRandom = new Dictionary <string, Random>();
foreach (string chr in segmentation.ScoreByChr.Keys)
{
perChromosomeRandom[chr] = new MersenneTwister(seedGenerator.NextFullRangeInt32(), true);
}
tasks = new List <ThreadStart>();
foreach (string chr in segmentation.ScoreByChr.Keys)
{
tasks.Add(new ThreadStart(() =>
{
int[] ina = inaByChr[chr];
int[] lengthSeg;
double[] segmentMeans;
ChangePoint.ChangePoints(segmentation.ScoreByChr[chr], sbdry, out lengthSeg, out segmentMeans, perChromosomeRandom[chr],
dataType: "logratio", alpha: this._alpha, nPerm: nPerm,
pMethod: pMethod, minWidth: minWidth, kMax: kMax, nMin: nMin, trimmedSD: trimmedSD,
undoSplits: this._undoMethod, undoPrune: undoPrune, undoSD: undoSD, verbose: verbose);
Segmentation.Segment[] segments = new Segmentation.Segment[lengthSeg.Length];
int cs1 = 0, cs2 = -1; // cumulative sum
for (int i = 0; i < lengthSeg.Length; i++)
{
cs2 += lengthSeg[i];
int start = ina[cs1];
int end = ina[cs2];
segments[i] = new Segmentation.Segment();
segments[i].start = segmentation.StartByChr[chr][start]; // Genomic start
segments[i].end = segmentation.EndByChr[chr][end]; // Genomic end
cs1 += lengthSeg[i];
}
lock (segmentByChr)
{
segmentByChr[chr] = segments;
}
}));
}
Parallel.ForEach(tasks, task => task.Invoke());
// segmentation.SegmentationResults = new Segmentation.GenomeSegmentationResults(segmentByChr);
Console.WriteLine("{0} Completed CBS tasks", DateTime.Now);
Console.WriteLine("{0} Segmentation results complete", DateTime.Now);
return(segmentByChr);
}
/// <summary>
/// Outputs:
/// lengthSeg
/// segmentMeans
/// </summary>
/// <param name="genomeData"></param>
/// <param name="sbdry"></param>
/// <param name="lengthSeg">segment lengths</param>
/// <param name="segmentMeans">segment means</param>
/// <param name="dataType">"logratio" or "binary"</param>
/// <param name="alpha"></param>
/// <param name="nPerm"></param>
/// <param name="pMethod"></param>
/// <param name="minWidth"></param>
/// <param name="kMax"></param>
/// <param name="nMin"></param>
/// <param name="trimmedSD"></param>
/// <param name="undoSplits">"none" or "prune" or "sdundo"</param>
/// <param name="undoPrune"></param>
/// <param name="undoSD"></param>
/// <param name="verbose"></param>
/// <param name="nGrid"></param>
/// <param name="tol"></param>
public static void ChangePoints(double[] genomeData, uint[] sbdry,
out int[] lengthSeg, out double[] segmentMeans, Random rnd,
string dataType = "logratio", double alpha = 0.01,
uint nPerm = 10000, string pMethod = "hybrid", int minWidth = 2, int kMax = 25,
uint nMin = 200, double trimmedSD = -1, SegmentSplitUndo undoSplits = SegmentSplitUndo.None,
double undoPrune = 0.05, double undoSD = 3, int verbose = 1,
int nGrid = 100, double tol = 1E-6)
{
if (trimmedSD <= 0)
{
trimmedSD = Helper.MedianAbsoluteDeviation(Helper.Diff(genomeData)) / Math.Sqrt(2);
}
// start with the whole
List <int> segEnd = new List <int>();
segEnd.Add(0); // inclusive
segEnd.Add(genomeData.Length); // exclusive
int k = segEnd.Count;
List <int> changeLocations = new List <int>();
int nChangePoints = 0;
int[] iChangePoint = null;
while (k > 1)
{
int currentN = segEnd[k - 1] - segEnd[k - 2];
if (verbose >= 3)
{
Console.Write(".... current segment: {0} - {1} \n", segEnd[k - 2] + 1, segEnd[k - 1]);
}
if (currentN >= 2 * minWidth)
{
double[] currentGenomeData = new double[currentN];
Array.Copy(genomeData, segEnd[k - 2], currentGenomeData, 0, currentN);
// check whether hybrid method needs to be used
bool hybrid = false;
double delta = 0.0;
if (pMethod.Equals("hybrid") && nMin < currentN)
{
hybrid = true;
delta = (kMax + 1.0) / currentN;
}
// if all values of current.genomdat are the same don't segment
if (currentGenomeData.Max() == currentGenomeData.Min())
{
nChangePoints = 0;
}
else
{
// centering the current data will save a lot of computations later
double currentAverage = currentGenomeData.Average();
Helper.InplaceSub(currentGenomeData, currentAverage);
// need total sum of squares too
double currentTSS = Helper.WeightedSumOfSquares(currentGenomeData, null);
ChangePoint.FindChangePoints(currentGenomeData, currentTSS, nPerm, alpha,
out nChangePoints, out iChangePoint, dataType.Equals("binary"),
hybrid, minWidth, kMax, delta, nGrid, sbdry, tol, rnd);
}
}
else
{
nChangePoints = 0;
}
// Save the change location
// segEnd[k - 1] will be removed when nChangePoints == 0
if (nChangePoints == 0)
{
changeLocations.Add(segEnd[k - 1]);
}
// Offset iChangePoint by segEnd[k - 2]
for (int i = 0; i < nChangePoints; i++)
{
iChangePoint[i] += segEnd[k - 2];
}
switch (nChangePoints) // switch by the number of change points
{
case 0: // no change point
segEnd.RemoveAt(k - 1); // Remove the last element
break;
case 1: // one change point
segEnd.Insert(k - 1, iChangePoint[0]);
break;
case 2: // two change points
segEnd.InsertRange(k - 1, iChangePoint);
break;
default:
Console.Error.WriteLine("There should be 0, 1, or 2 change points");
break;
}
k = segEnd.Count;
if (verbose >= 3)
{
Console.Write(".... segments to go: {0} \n", String.Join(" ", segEnd));
}
}
changeLocations.Reverse(); // changeLocations is no longer needed
List <int> segEnds = changeLocations;
int nSeg = segEnds.Count;
segEnds.Insert(0, 0);
lengthSeg = Helper.Diff(segEnds.ToArray());
if (nSeg > 1)
{
if (undoSplits == SegmentSplitUndo.Prune)
{
lengthSeg = ChangePointsPrune(genomeData, lengthSeg, changeCutoff: undoPrune);
}
if (undoSplits == SegmentSplitUndo.SDUndo)
{
lengthSeg = ChangePointsSDUndo(genomeData, lengthSeg, trimmedSD, changeSD: undoSD);
}
}
segmentMeans = new double[lengthSeg.Length];
int ll = 0, uu = 0;
for (int i = 0; i < lengthSeg.Length; i++)
{
uu += lengthSeg[i];
// Works even if weights == null
segmentMeans[i] = Helper.WeightedAverage(genomeData, null, iStart: ll, iEnd: uu);
ll = uu;
}
}
