Description Usage Arguments Details Value Author(s) Examples
This function performs the moving window chi-square calculation. It is written in C, so is quite fast.
1 | do.aGFF.calc(x, window, thresh)
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x |
An |
window |
An integer value, representing the number of basepairs to include in the windowed chi-square calculation |
thresh |
The quantile of the data distribution for each sample that will be used to classify a probe as positive |
A window size on the order of 2-3 times the average size of fragments from sonication, digestion, etc. and containing at least 8-10 probes is the recommended size. Larger size windows are probably more sensitive, but obviously reduce the accuracy with which boundaries of signal can be called.
A threshold of between 0.9 and 0.99 seems empirically to be adequate. If one plots the histogram of data values and there is an obvious better choice (such as a bimodal distribution, with one peak representing enrichment), a more data-driven approach may yield better results.
An object of class aGFFCalc
Sean Davis <sdavis2@mail.nih.gov>
1 2 3 | data(example.agff)
example.agffcalc <- do.aGFF.calc(example.agff,window=1000,thresh=0.9)
example.agffcalc
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