methp: Estimate DNA methylation
In charm: Analysis of DNA methylation data from CHARM microarrays

Description Usage Arguments Details Value Author(s) See Also Examples

Estimate DNA methylation from McrBC/CHARM microarray data in terms of log-ratios or percentages.

methp(dat, spatial = TRUE, bgSubtract = TRUE, withinSampleNorm = "loess", 
	scale = c(0.99, 0.99), betweenSampleNorm = "quantile", 
	controlProbes = NULL, controlIndex = NULL, excludeIndex = NULL,
	commonMethPercentParams = NULL, 
	verbose = TRUE, returnM = FALSE, 
	plotDensity = NULL, plotDensityGroups = NULL)

`dat`	a TilingFeatureSet object
`spatial`	boolean indicating whether to correct spatial artefacts
`bgSubtract`	boolean indicating whether to estimate and remove background signal before computing log-ratios
`withinSampleNorm`	within-sample normalization method. Choices are "loess" and "none". "loess" uses the control-probe loess procedure described in Aryee et al., 2011 (PMID: 20858772).
`scale`	a numeric vector (x,y). The xth percentile of each sample is scaled to represent y% methylation. The default c(0.99, 0.99) means probes in the 99% percentile represent 99% methylation.
`betweenSampleNorm`	between-sample normalization method. Choices are "quantile", "sqn", and "none". See Details for more fine-grained control.
`controlProbes`	character string of the label(s) assigned to non-CpG control probes in the array design file, i.e. in the container column of the .ndf design file for your array. The getContainer function from the oligo package can be used do see the container values for all pm probes. This argument is used only if controlIndex is not provided. Either this or controlIndex must be provided.
`controlIndex`	a numeric vector of probe indices indicating which pm probes are the non-CpG control probes (can be obtained using getControlIndex). Either this or controlProbes must be provided.
`excludeIndex`	a numeric vector of probe indices indicating which pm probes to ignore when creating the between-array normalization target distributions. These probes are also removed from all the plots created if plotDensity is specified, however be aware that they ARE still returned in the output of methp (just without having had any between-array normalization applied to them).
`commonMethPercentParams`	boolean indicating whether a common set of parameters should be used for all samples when converting M-values to percentage methylation.
`verbose`	boolean: Verbose output?
`returnM`	boolean. Return M-values without converting to percentage methylation estimates
`plotDensity`	if specified this is the filename of the pdf diagnostic density plots.
`plotDensityGroups`	numeric vector of group labels used to color lines in the diagnostic density plots (see plotDensity option)

This function provides probe-level estimates of percentage DNA methylation from CHARM microarray data.

A matrix of probe-level percentage methylation estimates, one column per sample. If the dat argument contains ff rather than matrix objects (as when it is produced by readCharm after loading the ff package), the output will be an ff object.

Martin Aryee <aryee@jhu.edu>

readCharm