## S3 method for class 'qvalue'
plot(x, rng = c(0, 0.1), ...)
Arguments
x
A q-value object.
rng
Range of q-values to show. Optional
...
Additional arguments. Currently unused.
Details
The function plot allows one to view several plots:
The estimated pi_0 versus the tuning parameter
lambda.
The q-values versus the p-values.
The number of significant tests versus each q-value cutoff.
The number of expected false positives versus the number of
significant tests.
This function makes four plots. The first is a plot of the
estimate of pi_0 versus its tuning parameter
lambda. In most cases, as lambda
gets larger, the bias of the estimate decreases, yet the variance
increases. Various methods exist for balancing this bias-variance
trade-off (Storey 2002, Storey & Tibshirani 2003, Storey, Taylor
& Siegmund 2004). Comparing your estimate of pi_0 to this
plot allows one to guage its quality. The remaining three plots
show how many tests are called significant and how many false
positives to expect for each q-value cut-off. A thorough discussion of
these plots can be found in Storey & Tibshirani (2003).
Storey JD and Tibshirani R. (2003) Statistical significance for
genome-wide experiments. Proceedings of the National Academy of Sciences,
100: 9440-9445. http://www.pnas.org/content/100/16/9440.full
Storey JD, Taylor JE, and Siegmund D. (2004) Strong control,
conservative point estimation, and simultaneous conservative
consistency of false discovery rates: A unified approach. Journal of
the Royal Statistical Society, Series B, 66: 187-205.
# import data
data(hedenfalk)
p <- hedenfalk$p
qobj <- qvalue(p)
plot(qobj, rng=c(0.0, 0.3))
Results
R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)
R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.
R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.
Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.
> library(qvalue)
> png(filename="/home/ddbj/snapshot/RGM3/R_BC/result/qvalue/plot.qvalue.Rd_%03d_medium.png", width=480, height=480)
> ### Name: plot.qvalue
> ### Title: Plotting function for q-value object
> ### Aliases: plot, plot.qvalue
> ### Keywords: plot
>
> ### ** Examples
>
> # import data
> data(hedenfalk)
> p <- hedenfalk$p
> qobj <- qvalue(p)
>
> plot(qobj, rng=c(0.0, 0.3))
>
>
>
>
>
>
> dev.off()
null device
1
>