RPS-package(RPS)R Documentation

Reproducibility Probability Score(RPS) for Microarray Data

Description

Reproducibility probability score incorporates measurement variability across labs for gene selection. A gene with a large RPS means that it is more likely to be differentially expressed; and if other labs were to perform the same experiment,the differential expression of this gene is more likely to be reaffirmed.

Details

Package: RPS
Type: Package
Version: 1.0
Date: 2006-05-21
License: GPL

Author(s)

Guixian Lin<glin2@uiuc.edu> and Sheng Zhong<szhong@ad.uiuc.edu>

References

See Also

RPS.load, RPS.readnew, RPS.select

Examples


        load("ABI.RData")  #load precomputed correlations of  genes for different platforms using MAQC microarray dataset.Here the platform is "ABI"
                              #Right now,one of the following platform(ABI,AFFY,AGL,GEH or ILM) can be  specified.
        ##After loading "ABI.RData",two R objects( corr and probenames) are in the current enviroment.                        
        ##samples information
        test.sample.info=c(rep(1,5),rep(2,5)) #two samples,first 5 replicates are from sample A, the next 5 replicates are from sample B.
        K=10  # the number of labs to be simulated,recommendly between 30 and 50.
        n.replicate=5  #the replicates for each sample
        p.value=1e-03 # p-value threshold for computing RPS 
        FC=2.5  # fold change threshold for computing RPS 
        MAQC.test=RPS.readnew("ABI_12091.txt",transformed=F)  #read the actural microarray data to compute RPS;Here The data set include 3 labs,4 samples , and 5 replicates 
                                                              #if transform==F, then the actural data need  log2-tranformation.
        results=RPS.select(MAQC.test[,2:11],test.sample.info,corr,n.replicate,test="t",p.value,FC,K,flag=T) #MAQC.test[,2:11] are samples A and B with 5 replications repectively from Lab 1, 
                                                                                                     #and results is a list,which includes RPS and K simulation data
        ##If the test data set only contains partly genes in MAQC data set or you are only interested in some genes,then you can compute 
        ## the RPS for those genes only
        ## For example, only first 200 genes in your test data set, use :
        ## subindex= is.element(probenames,MAQC.test[1:200,1])
        ## subcorr=list(corr.Labs=corr$corr.Labs[subindex],var.matrix=corr$var.matrix[,subindex])
        ##results=RPS.select(MAQC.test[1:200,2:11],test.sample.info,subcorr,n.replicate,test="t",p.value,FC,K,flag=T) 
        
        
        summary(results$RPS)
         
        #or choose to show RPS for each probe set 
        probeSetName=MAQC.test[,1] ##First column is the probe set names
        data.frame(probeSetName,results$RPS)[1:20,] ##Here is an example to show RPS for the first 20 probe set
        #obtain the summary expression data for the  j-th new imaginary lab
        j=2;#make sure j<=K
        simu.dataOneLab=results$simu.data[,1:(n.replicate*2)+(j-1)*(n.replicate*2)]
        colnames( simu.dataOneLab)<-c(rep("s1",n.replicate),rep("s2",n.replicate)) #first n.replicates are sample A,and the next n.replicates are sample B
        summary(simu.dataOneLab)
        
        

[Package RPS version 1.0 Index]