FDR(OCplus)
FDR()所属R语言包:OCplus
Compute FDR for general scenarios
一般情况下计算FDR
译者:生物统计家园网 机器人LoveR
描述----------Description----------
FDR computes the false discovery rate for comparing gene expression between two groups of subjects when the distribution of the test statistic under the null and alternative hypothesis are both mixtures of t-distributions. CDF and CDFmix calculate these mixtures.
FDR计算错误发现率比较两组受试者的基因表达时,下空和替代假说的检验统计量的分布是T-分布两种混合物。 CDF和CDFmix计算这些混合物。
用法----------Usage----------
FDR(x, n1, n2, pmix, D0, p0, D1, p1, sigma)
CDF(x, n1, n2, D, p, sigma)
CDFmix(x, n1, n2, pmix, D0, p0, D1, p1, sigma)
FDR.paired(x, n, pmix, D0, p0, D1, p1, sigma)
CDF.paired(x, n, D, p, sigma)
CDFmix.paired(x, n, pmix, D0, p0, D1, p1, sigma)
参数----------Arguments----------
参数:x
vector of quantiles (two-sample t-statistics)
向量位数(两样本t-统计)
参数:n, n1, n2
vector of sample sizes (as subjects per group)
样本大小的矢量(每组科目)
参数:pmix
the proportion of non-differentially expressed genes
非差异表达基因的比例
参数:D0
vector of effect sizes for the null distribution
空分布的影响大小的向量
参数:p0
vector of mixing proportions for D0; must be the same length as D0 and sum to one
混合比例为向量D0;必须D0“总和相同长度的一个
参数:D1
vector of effect sizes for the alternative distribution
向量的替代分布的影响大小
参数:p1
vector of mixing proportions for D1, same as p0
向量的混合比例为D1,p0相同
参数:D, p
generic vectors of effect sizes and mixing proportions as above
上述影响的大小和混合比例的通用向量
参数:sigma
the standard deviation
标准偏差
Details
详情----------Details----------
These functions are designed for a simple experimental setup, where we wish to compare gene expression between two groups of subjects of size n1 and n2 for an unspecified number of genes, using an equal-variance t-statistic.
这些功能被设计为一个简单的实验装置,在这里我们想比较两组大小n1主体之间的基因表达和n2基因的数目不详,使用方差相等的t-统计。
100pmix% of the genes are assumed to be not differentially expressed. The corresponding t-statistics follow a mixture of t-distributions; this is more general than the usual central t-distribution, because we may want to include genes with biologically small effects under the null hypothesis (Pawitan et al., 2005). The other 100(1-pmix)% genes are assumed to be differentially expressed; their t-statistics are also mixtures of t-distributions.
100pmix%的基因被假定为没有差异表达。相应的t-统计遵循的t-分布的混合物,这是比一般的中央t分布更一般的,因为我们可能要包括生物小的影响下虚无假设(Pawitan等,2005)。基因。其他100(1 - pmix)%的基因差异表达假设t-统计量T-分布的混合物。
The mixture proportions of t-distributions under the null and alternative hypothesis are specified via p0 and p1, respectively. The individual t-distributions are specified via the means D0 and D1 and the standard deviation sigma of the underlying data (instead of the mathematically more obvious, but less intuitive non centrality parameters). As the underlying data are the logarithmized expression values, D0 and D1 can be interpreted as average log-fold change between conditions, measured in units of sigma. See Examples.
通过p0和p1,分别指定空和替代假说下的T-分布的混合比例。个人的T-分布通过手段D0和D1和标准偏差指定sigma底层数据(而不是数学较为明显,但不太直观的非核心参数)。作为底层数据logarithmized的的表达值,D0和D1log倍的平均变化之间在单位sigma计量的条件,可以作为解释。参阅范例。
CDF computes the cumulative distribution function for a mixture of t-distributions based on means D and standard deviation sigma with mixture proportions p. This function is the work horse for CDFmix.
CDF计算为手段的基础混合物的T-分布的累积分布函数D和标准偏差sigma混合比例p。这个函数是马CDFmix工作。
Note that the base functions (FDR, CDFmix, CDF) assume two groups of experimental units; the .paired functions provide the same functionality for one group of paired observations.
请注意,基函数(FDR,CDFmix,CDF)假设两批试点单位;.paired功能提供了一组配对的意见相同的功能。
The distribution functions call pt for computation; correspondingly, the quantiles x and all arguments that define degrees of freedom and non centrality parameters (n1, n2, D0, D1, sigma) can be vectors, and will be recycled as necessary.
相应的分布函数调用pt计算;,位数x“的所有参数定义的自由程度和非核心参数(n1,n2,D0 ,D1,sigma)可以成为向量,将作为必要的回收。
值----------Value----------
The appropriate vector of FDRs or probabilities.
适当的向量FDRs或概率。
作者(S)----------Author(s)----------
Y. Pawitan and A. Ploner
参考文献----------References----------
参见----------See Also----------
TOC, samplesize
TOC,samplesize
举例----------Examples----------
# FDR for H0: 'log fold change is zero'[FDR为H 0:“log倍的变化是零”]
# vs. H1: 'log fold change is -1 or 1' [与H1的:“log倍的变化是-1或1”]
# (ie two-fold up- or down regulation) [(即两折向上或向下调节)]
FDR(1:6, n1=10, n2=10, pmix=0.90, D0=0, p0=1,
D1=c(-1,1), p1=c(0.5, 0.5), sigma=1)
# Include small log fold changes in the H0[包括小log在H 0倍]
# Naturally, this increases the FDR[当然,这大大增加了FDR]
FDR(1:6, n1=10, n2=10, pmix=0.90, D0=c(-0.25,0, 0.25), p0=c(1/3,1/3,1/3),
D1=c(-1,1), p1=c(0.5, 0.5), sigma=1)
# Consider an asymmetric alternative[考虑非对称替代]
# 10 percent of the regulated genes are assumed to be four-fold upregulated[被假定为4倍,上调10%的调节基因]
FDR(1:6, n1=10, n2=10, pmix=0.90, D0=0, p0=1,
D1=c(-1,1,2), p1=c(0.45, 0.45, 0.1), sigma=1)
转载请注明:出自 生物统计家园网(http://www.biostatistic.net)。
注:
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