Description Usage Arguments Details Value Author(s) References See Also Examples
Moment estimation of the parameters of a scaled F-distribution given one of the degrees of freedom.
This function is called internally by eBayes
and squeezeVar
and is not usually called directly by a user.
1 2 |
x |
numeric vector or array of positive values representing a sample from a scaled F-distribution. |
df1 |
the first degrees of freedom of the F-distribution. Can be a single value, or else a vector of the same length as |
covariate |
if non- |
winsor.tail.p |
numeric vector of length 1 or 2, giving left and right tail proportions of |
trace |
logical value indicating whether a trace of the iteration progress should be printed. |
fitFDist
implements an algorithm proposed by Smyth (2004).
It estimates scale
and df2
under the assumption that x
is distributed as scale
times an F-distributed random variable on df1
and df2
degrees of freedom.
The parameters are estimated using the method of moments, specifically from the mean and variance of the x
values on the log-scale.
fitFDistRobustly
is similar to fitFDist
except that it computes the moments of the Winsorized values of x
, making it robust against left and right outliers.
Larger values for winsor.tail.p
produce more robustness but less efficiency.
The robust method is described by Phipson (2013).
A list containing the components
scale |
scale factor for F-distribution. A vector if |
df2 |
the second degrees of freedom of the F-distribution. |
Gordon Smyth and Belinda Phipson
Smyth, G. K. (2004). Linear models and empirical Bayes methods for assessing differential expression in microarray experiments. Statistical Applications in Genetics and Molecular Biology, 3, No. 1, Article 3. http://www.statsci.org/smyth/pubs/ebayes.pdf
Phipson, B. (2013). Empirical Bayes modelling of expression profiles and their associations. PhD Thesis. University of Melbourne, Australia. http://repository.unimelb.edu.au/10187/17614
Phipson, B., and Smyth, G. K. (2013). Robust empirical Bayes estimation protetcts against hyper-variable genes and improves power to detect differential expression in RNA-seq data. Bioinformatics Division, Walter and Eliza Hall Institute of Medical Research, Australia
This function is called by squeezeVar
, and hence by ebayes
and eBayes
.
This function calls trigammaInverse
.
1 2 |
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.