fdrfourier(cycle)
fdrfourier()所属R语言包:cycle
Calculation of the false discovery rates (FDR) for periodic expression
定期表达计算错误发现率(FDR)
译者:生物统计家园网 机器人LoveR
描述----------Description----------
The function calculates the empirical FDR based on derived Fourier scores derived by fourierscore for the observed expression and the comparison with scores derived for different background model generated by backgroundData.
函数计算FDR的经验的基础上派生的衍生傅立叶分数fourierscore所观察到的表达和比较不同背景backgroundData的生成模型得出的分数。
用法----------Usage----------
fdrfourier(eset,T,times,background.model="rr",N=100,progress=FALSE)
参数----------Arguments----------
参数:eset
object of the class “ExpressionSet”
对象“ExpressionSet类”
参数:T
cycle period
周期
参数:times
time of measurements
时间测量
参数:background.model
model for generation of background data: “rr”- permutation within rows, “gauss”- Gaussian background, “ar1”- AR1 models
模型生成背景资料:“RR” - 行内置换,“高斯” - 高斯背景下,“AR1” - AR1的模型
参数:N
number of generated data sets for the background distribution
产生的数据的数量设置为背景分布
参数:progress
if set to TRUE, a progress of calculations is reported
如果设置为true,则计算的进展报告
Details
详情----------Details----------
To assess the significance of the Fourier score obtained for the original gene expression time series, the probability has to be calculated of how often such a score would be observed by chance based on the chosen background distribution. The statistical significance is given by the calculated false discovery rate. It is defined here as the expected proportion of false positives among all genes detected as periodically expressed. Mathematical details can be found in the given reference.
评估获得原癌基因的表达时间序列傅立叶得分的意义,经常出现这样的比分将如何偶然观察的基础上选定的背景分布计算概率。计算错误发现率的统计学意义。它在这里被定义为预期的比例定期对所有检测的基因之间的误报。数学的细节,可以发现在给定的参考。
值----------Value----------
List with FDR for the features of the eset object (fdr), and Fourier scores for ExpressionSet object (F) and
FDR为ESET对象的特点(fdr),傅立叶分数ExpressionSet对象(F)和名单
注意----------Note----------
This is the main function of the cycle package. Note that the calculation of FDR employing empirical background distributions can require considerable time (up to several days for large gene expression data sets).
这是cycle包的主要功能。请注意,FDR用人经验背景分布的计算可能需要相当长的时间(最多几天大的基因表达数据集)。
Importantly, this function evaluates soley the exprs matrix and no information is used from the phenoData. In particular, the ordering of samples (arrays) is the same as the ordering of the columns in the exprs matrix. Also, replicated arrays in the exprs matrix are treated as independent i.e. they should be averagered prior to analysis or placed into different
重要的是,这个函数的计算结果掌上明珠,从exprs的phenoData矩阵和没有信息。样本(阵列)的顺序,特别是作为exprs矩阵中列的顺序是相同的。此外,exprs矩阵复制阵列被视为独立的,即他们分析之前,应averagered或放置到不同的
作者(S)----------Author(s)----------
Matthias E. Futschik (<a href="http://www.cbme.ualg.pt/mfutschik_cbme.html">http://www.cbme.ualg.pt/mfutschik_cbme.html</a>)
参考文献----------References----------
举例----------Examples----------
if (interactive()){
set.seed(1)
data(yeast) # loading the reduced CDC28 yeast set (from the Mfuzz package)[载入减少CDC28酵母集(从Mfuzz包)]
# Data preprocessing [数据预处理]
yeast <- filter.NA(yeast) # filters genes with more than 25% of the expression values missing [过滤器,超过25%的表达基因值缺失]
yeast <- fill.NA(yeast) # for illustration only; rather use knn method for [只用于说明目的,而是使用KNN方法]
yeast <- standardise(yeast)
# []
T.yeast <- 85 # cell cycle period (t=85min)[单元周期(T = 85分钟)]
times.yeast <- pData(yeast)$time # time of measurements[时间测量]
#[]
yeast.test <- yeast[1:600,] # To speed up the example[加快范例]
#[]
NN <- 50 # number of generated background models[数产生的背景模型]
# Here, a small number was chosen for demonstration purpose.[在这里,一个小数目,被选为示范的目的。]
# For the actual analysis, rather set N = 1000 [对于实际的分析,而不是设置N = 1000]
# Calculation of FDRs[计算的FDRs]
# i) based on random permutation as background model[I)的基础上随机排列为背景模型]
fdr.rr <- fdrfourier(eset=yeast.test,T=T.yeast,
times=times.yeast,background.model="rr",N=NN,progress=TRUE)
# ii) based on Gaussian distribution [ii)根据高斯分布]
fdr.g <- fdrfourier(eset=yeast.test,T=T.yeast,
times=times.yeast,background.model="gauss",N=NN,progress=TRUE)
# iii) based on AR(1) models as background[iii)根据AR(1)模型作为背景]
fdr.ar1 <- fdrfourier(eset=yeast.test,T=T.yeast,
times=times.yeast,background.model="ar1",N=NN,progress=TRUE)
# Number of significant genes based on diff. background models[数的显著基因上的差异。背景模型]
sum(fdr.rr$fdr < 0.1)
sum(fdr.g$fdr < 0.1)
sum(fdr.ar1$fdr < 0.1)
# Plot top scoring gene[绘制得分最高的基因]
plot(times.yeast,exprs(yeast.test)[order(fdr.ar1$fdr)[1],],type="o",
xlab="Time",ylab="Expression",
main=paste(featureNames(yeast.test)[order(fdr.ar1$fdr)[1]],"-- FDR:",
fdr.ar1$fdr[order(fdr.ar1$fdr)[1]]))
# List significant genes[列出显著的基因]
fdr.ar1$fdr[which(fdr.ar1$fdr < 0.1)]
}
转载请注明:出自 生物统计家园网(http://www.biostatistic.net)。
注:
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