segChrom {tilingArray} | R Documentation |
This function calls the segment
function for each strand of one or more chromosomes specified by the user.
segChrom(y, probeAnno, chr=1, nsegs, nrBasesPerSegment = 1500, step=7, confint=FALSE, confintLevel=0.95, save=FALSE, savedir=NULL)
y |
ExpressionSet or matrix containing the data to be segmented. |
probeAnno |
environment with probe annotations. See
package davidTiling for an example (?probeAnno). |
chr |
integer scalar or vector specifying which chromosome(s) to segment. |
nsegs |
integer vector specifying the maximum number of segments (= 1 + maximum
number of change points) for each chromosome and strand. If missing, this value is calculated by dividing the number of bases on a chromosome by nrBasesPerSegment . |
nrBasesPerSegment |
integer (length 1): maximum length of a segment. |
step |
integer, indicating the minimum distance between the consecutive probes. In cases when probes are offset by less than step bases, the probes are sampled to achieve the desired spacing. |
confint |
logical scalar. If TRUE , confidence intervals for each change-point are calculated. Otherwise (FALSE ), no confidence intervals are returned. |
confintLevel |
numeric scalar between 0 and 1 indicating the probability level for the confidence intervals calculated for each change-point. |
save |
logical scalar. If TRUE the results of each segmentation are saved to file in the savedir directory. If FALSE (default), the results are not saved to file. |
savedir |
optional character string specifying the filepath where the segmentation results will be saved. Only used when save=TRUE . Defaults to current working directory. |
This function is a wrapper for the segment
function which fits piecewise constant curves to along chromosome data. It calls segment
for each strand of the chromosomes specified by the chr
argument. Refer to the segment
help page for further details.
An environment with containing S4 objects of class "segmentation"
called "1.+", "1.-", etc (depending on chr
), where "+" and "-" indicates the strand and the preceding number refers to the chromosome number. If save=TRUE
, a series of files, "1.+.rda", "1.-.rda", etc (depending on chr
) are saved in the directory specified.
Matt Ritchie <ritchie@ebi.ac.uk> and Wolfgang Huber <huber@ebi.ac.uk>
## library("davidTiling") ## data("davidTiling") ## data("probeAnno") ## isDNA = seq(1:3) ## yn = normalizeByReference(davidTiling[,-isDNA],davidTiling[,isDNA], probeAnno=probeAnno) ## seg1 = segChrom(yn, probeAnno, chr=1) # this will take a while to run!