R/estLODR.R

Defines functions estLODR

Documented in estLODR

#' Estimate Limit of Detection of Ratios (LODR)
#'
#' @param exDat    list, contains input data and stores analysis results
#' @param kind      "ERCC" or "Sim"
#' @param prob      probability, ranging from 0 - 1, default is 0.9
#' 
#' @details
#' This is the function to estimate a limit of detection of ratios (LODR) for a
#' a chosen probability and threshold p-value for the fold changes in the ERCC
#' control ratio mixtures.
#' 
#' @examples
#' data(SEQC.Example)
#'  
#' exDat <- initDat(datType="array", isNorm=FALSE, 
#'                  exTable=UHRR.HBRR.arrayDat,
#'                  filenameRoot="testRun", sample1Name="UHRR",
#'                  sample2Name="HBRR", erccmix="RatioPair", 
#'                  erccdilution = 1, spikeVol = 50, 
#'                  totalRNAmass = 2.5*10^(3), choseFDR=0.01)
#'                  
#' exDat <- est_r_m(exDat)
#'                   
#' exDat <- dynRangePlot(exDat)
#'
#' exDat <- geneExprTest(exDat)
#' 
#' exDat <- estLODR(exDat, kind = "ERCC", prob = 0.9)
#' 
#' exDat$Figures$lodrERCCPlot
#'
#' @export
#' 
estLODR <- function(exDat,kind = "ERCC", prob=0.9){
    ##############
    #### LODR ####
    ##############
    ### Select fitting parameters
    # pval.cutoff default is .001
    # probability cutoff is .9
    # kind can be ERCC or Sim
    sampleInfo <- exDat$sampleInfo
    erccInfo <- exDat$erccInfo
    plotInfo <- exDat$plotInfo
    
    pval.cutoff<- exDat$Results$p.thresh 
    filenameRoot<-sampleInfo$filenameRoot
    FCcode <- erccInfo$FCcode
    #FCcode = data.frame(Ratio = c("4:1","1:1","1.5:1","2:1"),FC=c(4,1,.667,.5))
    legendLabels = erccInfo$legendLabels
    #legendLabels = FCcode$Ratio
    
    colScale <- plotInfo$colScale
    fillScale <- plotInfo$fillScale
    
    ### Read in results for LODR ####
    ### Modify this file path to work with other ERCC data
    ### Note that you must format your provided data in the same manner as the 
    ### provided example
    ### i.e. the column headings of your selected datamust match those of the 
    ### provided examples
    
    if(kind == "ERCC"){
        erccPval <- file.exists(paste(filenameRoot,"ERCC","Pvals.csv"))
        allPval <- file.exists(paste0(filenameRoot, ".All.Pvals.csv"))
        if((erccPval == TRUE)&(allPval==TRUE)){
            pval.res = read.csv(file=paste(filenameRoot,"ERCC","Pvals.csv"),
                                header=TRUE)  
        }
        if(allPval == TRUE){
            pval.res = read.csv(file = paste0(filenameRoot, ".All.Pvals.csv"),
                                header = TRUE)
            pval.res <- pval.res[grep("ERCC-00",pval.res$Feature),]
        }else{
            cat(paste0("\n",filenameRoot," ERCC Pvals.csv file is missing."))
            cat("\nExiting LODR estimation...\n")
            return(exDat)
        }
    }
    if (kind == "Sim"){
        if(file.exists(paste(filenameRoot,"Sim Pvals.csv"))){
            pval.res<-read.csv(paste(filenameRoot,kind,"Pvals.csv"),header=TRUE)  
        }else{
            cat(paste0("\n",filenameRoot," Sim Pvals.csv is missing.",
                       "\nExiting LODR estimation...\n"))
            return(exDat)
        }  
    }
    
    
    names(pval.res)[1]= "Feature"
    
    #Check number of data points, throw warning if too few
    oneSet <- pval.res[which(pval.res$Fold == 1),]
    sizeP <- dim(oneSet)[1]
    if(!(sizeP > 5)) stop("Not enough data points for LODR estimation")
    
    cat(paste("\nEstimating",kind,"LODR\n"))
    #### Function used to estimate LODR and its uncertainty
    LODR<-function(pval,mn,cutoff,prob){
        cutoff<-log10(cutoff)
        fit<-locfit(log10(pval)~lp(log10(mn)),maxk=300)
        X<-preplot(fit,band="pred",newdata=log10(mn))
        
        ### See plot of fit
        #plot(fit,band="pred",get.data=TRUE,xlim=range(log10(mn)))
        
        find.mn<-function(mn,fit,cutoff,prob){
            X<-preplot(fit,newdata=mn,band="pred")
            (X$fit+qnorm(prob)*X$se.fit-cutoff)^2
        }
        
        rng.mn<-range(log10(mn))
        
        ### Search in sections to get first crossing 
        segmented.search<-function(fit){
            X<-preplot(fit,newdata=min(log10(mn)),band="pred")
            if((X$fit+qnorm(prob)*X$se.fit)<cutoff){
                t.lodr<-list(minimum=min(log10(mn)),objective=0)
            } else{
                ppp<-.2
                t.lodr<-optimize(find.mn,c(rng.mn[1],sum(rng.mn*c(1-ppp,ppp))),
                                 fit=fit,cutoff=cutoff,prob=prob)
                while(t.lodr$objective>.0001&ppp<=1){
                    t.lodr<-optimize(find.mn,c(sum(rng.mn*c(1-ppp+.2,ppp-.2)),
                                               sum(rng.mn*c(1-ppp,ppp))),
                                     fit=fit,cutoff=cutoff,prob=prob)
                    ppp<-ppp+.2
                }
            }
            t.lodr
        }    
        
        lodr<-segmented.search(fit)
        
        ### Bootstrap to estimate uncertainty
        lodr.boot<-NULL
        for(ii in 1:500){
            y.boot<-X$fit+sample(residuals(fit),length(mn))
            #if(ii %in%c(20*(1:5))){points(log10(mn),y.boot,col=j); j<-j+1}
            fit.boot<-locfit(y.boot~lp(log10(mn)),maxk=300)
            lodr.boot<-c(lodr.boot,segmented.search(fit.boot)$minimum)
            if (ii %% 100 == 0){
                cat ("...")
            }
        }
        return(c(lodr$objective,lodr$minimum,quantile(lodr.boot,c(.05,.95))))
    }
    
    
    #### Apply to loaded data ####
    lodr.resPlot<-NULL; set.seed(1)
    lodr.resLess<-NULL; set.seed(1)
    
    #lodr.res<-NULL; set.seed(1)
    lineDat <-NULL
    
    pval.res$Ratio = NA
    FCcode$Ratio <- as.factor(FCcode$Ratio)
    for (i in 1:nlevels(FCcode$Ratio)){
        pval.res$Ratio[which(pval.res$Fold == 
                                 FCcode$FC[i])]=as.character(FCcode$Ratio[i])
    }
    
    #pval.res$Ratio <- as.factor(pval.res$Ratio)
    pval.res$Ratio <- factor(pval.res$Ratio, 
                             levels=as.character(FCcode$Ratio))
    for(i in 1:nlevels(FCcode$Ratio)){ # Analyze fold change groups separately
        
        grp<-which(pval.res$Ratio==FCcode$Ratio[i])  ### identify group members
        
        x<-pval.res$MnSignal[grp][pval.res$Pval[grp]!=0] 
        y<-pval.res$Pval[grp][pval.res$Pval[grp]!=0]
        
        fit<-locfit(log10(y)~lp(log10(x)),maxk=300)
        #x.new<-log10(pval.res$MnSignal[grp])
        x.new<-seq(min(log10(x)),max(log10(x)),length.out=100)
        X<-preplot(fit,band="pred",newdata=x.new)
        
        x.new<-10^x.new
        fitLine = 10^(X$fit)
        fitUpper = 10^(X$fit+qnorm(prob)*X$se.fit)
        fitLower = 10^(X$fit-qnorm(prob)*X$se.fit)
        fitData = data.frame(x.new,fitLine,fitUpper,fitLower,
                             Ratio = FCcode$Ratio[i])
        lineDat = rbind(lineDat,fitData)
        
        # ### Estimate LODR
        #lodr.res<-rbind(lodr.res,c(abs(log2(FCcode$FC[i])),LODR(y,x,
        # cutoff=pval.cutoff,prob=prob)))
        
        ### Estimate LODR
        if(FCcode$FC[i]!=1){
            t.res<-LODR(y,x,cutoff=pval.cutoff,prob=prob)
            t.res[-1]<-signif(10^t.res[-1],2)
            if(t.res[1]>.01){
                t.res[2]<-Inf
                t.res[3:4]<-NA
            }
            t.resLess <- t.res
            t.resLess[-1][t.resLess[-1] == 
                              signif(min(x),2)]<-paste("<",
                                                       signif(min(x),2),sep="")
            t.res[-1][t.res[-1]==signif(min(x),2)] <- Inf
        
        if(FCcode$FC[i]==1){
            t.res<-rep(NA,4)
            t.resLess<-rep(NA,4)
        } 
        lodr.resPlot<-rbind(lodr.resPlot,c(round(abs(log2(FCcode$FC[i])),3),
                                           t.res))
        lodr.resLess <- rbind(lodr.resLess,c(round(abs(log2(FCcode$FC[i])),3),
                                             t.resLess))
        }
    }
    pval.res = subset(pval.res,pval.res$Pval != 0)
    
    colnames(lodr.resLess)[1:3]<-c("|log2(Fold)|","MinError","Estimate")
    
    colnames(lodr.resPlot)[1:3]<-c("Ratio","MinError","Estimate")
    colnames(lodr.resLess)[1:3]<-c("Ratio","MinError","Estimate")
    
    lodr.resPlot <- as.data.frame(lodr.resPlot)
    lodr.resLess <- as.data.frame(lodr.resLess)
   
    lodr.resPlot$Ratio <- as.character(legendLabels[-which(FCcode$FC == 1)])
    lodr.resLess$Ratio <- as.character(legendLabels[-which(FCcode$FC == 1)]) 
    annoTable <- lodr.resLess[-c(2)]
   
    colnames(annoTable) <- c("Ratio",expression("LODR Estimate"), 
                             expression("90% CI Lower Bound"), 
                             expression("90% CI Upper Bound"))
    #### fix this need to get rid of the "1:1" hard coding...
    #annoTable <- annoTable[-which(annoTable$Ratio == "1:1"),]
    ####
    cat("\n")
    print(annoTable, quote = FALSE, row.names = FALSE)
    
    arrowDat = data.frame(Ratio = lodr.resPlot$Ratio, 
                          x = lodr.resPlot[,3], y = pval.cutoff, 
                          xend = lodr.resPlot[,3], yend = 0)
    arrowDat$x[grep('<',lodr.resLess[,3])] <- Inf
    
    #arrowDat = arrowDat[-which(arrowDat$FC == "1"),]
   
    arrowDat = arrowDat[which(is.finite(arrowDat$x)),]
    
    if(dim(arrowDat)[1] == 0){
        cat(paste("\nWarning! Estimated distribution of p-values does not",
                  "cross threshold p-value,\n",
                  "may be due to insufficient data quantity\n",
                  "Consider adjusting FDR choice.\n"))
        #break
    }
    if(exDat$sampleInfo$datType == "array"){
        xlabDE <- xlab("Average Fluorescence Intensity")
        xrange <- c(min(pval.res$MnSignal),max(pval.res$MnSignal))
        legendPos <- theme(legend.justification=c(1,0), legend.position=c(1,0))
    }
    if(exDat$sampleInfo$datType == "count"){
        xlabDE <- xlab("Average Counts")
        xrange <- c(1,max(pval.res$MnSignal))
        legendPos <- theme(legend.justification=c(0,0), legend.position=c(0,0))
    }
    
    ## create inset table
#    ttLODR <- ttheme_default(core=list(bg_fun = rectGrob(gp=gpar(fill=NA))))
    
    my_table <- tableGrob(d=annoTable,rows=NULL)
#     my_table <- tableGrob(d=annoTable,
#                           show.rownames=FALSE,
#                           gpar.coretext =gpar(fontsize=14),
#                           gpar.coltext=gpar(fontsize=14),
#                           gpar.rowtext=gpar(fontsize=14),
#                           gpar.corefill = gpar(fill = "grey85", col = "white"), 
#                           gpar.rowfill = gpar(fill = "grey80", col = "white"),
#                           gpar.colfill = gpar(fill = "grey80", col = "white"))
    
    # Appease R CMD Check
    MnSignal <- Pval <- Ratio <- xend <- yend <- NULL
    
    if(dim(arrowDat)[1]!=0){
        LODRplot <- ggplot(pval.res, aes(x=MnSignal,
                                         y=Pval,colour=Ratio)) + 
            geom_point(size = 6) + 
            scale_x_log10(limits = xrange) + 
            scale_y_log10(breaks = c(1e-12,1e-10,1e-8,1e-5,1e-4,
                                     1e-3,1e-2,1e-1,1e0))+
            geom_ribbon(data = lineDat, aes(x = x.new, 
                                            y = fitLine, 
                                            ymin=fitLower, 
                                            ymax=fitUpper,
                                            fill = Ratio), alpha = 0.3,
                        colour=NA,show.legend=FALSE) + 
            geom_line(data = lineDat,aes(x = x.new,
                                         y=fitLine, 
                                         colour = Ratio),show.legend = FALSE) + 
            colScale + fillScale + xlabDE + ylab("DE Test P-values") + 
            geom_hline(yintercept = pval.cutoff, linetype = 2, size = 2 ) + 
            geom_segment(data = arrowDat, aes(x = x,
                                              y = y, 
                                              xend = xend,
                                              yend = yend, 
                                              colour = Ratio), 
                         lineend = "round", arrow=arrow(length=unit(0.5,"cm")), 
                         size = 2, alpha = 0.6) + theme_bw()+ legendPos  
    }else{
        LODRplot <- ggplot(pval.res, aes(x=MnSignal, y=Pval, colour=Ratio)) + 
            geom_point(size = 6) + 
            scale_x_log10(limits = xrange) + 
            scale_y_log10(breaks = c(1e-12,1e-10,1e-8,1e-5,1e-4,
                                     1e-3,1e-2,1e-1,1e0)) +
            geom_ribbon(data = lineDat, aes(x = x.new, 
                                            y = fitLine, 
                                            ymin=fitLower, 
                                            ymax=fitUpper,
                                            fill = Ratio), alpha = 0.3,
                        colour= NA,show.legend=FALSE) + 
            geom_line(data = lineDat,aes(x = x.new,
                                         y=fitLine, 
                                         colour = Ratio),show.legend = FALSE) + 
            colScale + fillScale + xlabDE + ylab("DE Test P-values") + 
            geom_hline(yintercept = pval.cutoff, linetype = 2, size = 2 ) +
            theme_bw()+ legendPos
    }

    annotLODRplot <- grid.arrange(arrangeGrob(grobs = list(LODRplot, my_table), 
                                               ncol = 1, heights = c(2,0.5)))
    dev.off()
    
    nam <- paste0("lodr",kind,"Plot")
    exDat$Figures$plotLODR <- annotLODRplot
    
    names(exDat$Figures)[which(names(exDat$Figures) == "plotLODR")] <- nam
    
    nam <- paste("lodr.res",kind,sep = ".")
    exDat$Results$lodr.res <- lodr.resLess
    names(exDat$Results)[which(names(exDat$Results) == "lodr.res")] <- nam
    
    return(exDat)
}

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erccdashboard documentation built on Nov. 8, 2020, 5:50 p.m.