R/plotROC.R

Defines functions plotROC

Documented in plotROC

### plotROC.R --- 
#----------------------------------------------------------------------
## author: Thomas Alexander Gerds
## created: Jun 23 2016 (10:27) 
## Version: 
## last-updated: Dec  5 2020 (11:37) 
##           By: Thomas Alexander Gerds
##     Update #: 182
#----------------------------------------------------------------------
## 
### Commentary: 
## 
### Change Log:
#----------------------------------------------------------------------
## 
### Code:
##' Plot ROC curve 
##'
##' @title Plot ROC curves
#' @param x Object obtained with function \code{Score}
#' @param models Choice of models to plot
#' @param times Time point(s) specifying the prediction horizon
#' @param xlab Label for x-axis
#' @param ylab Label for y-axis
#' @param col line color
#' @param lwd line width
#' @param lty line style
#' @param cex point size
#' @param pch point style
#' @param legend logical. If \code{1L} draw a legend with the values
#'     of AUC.
#' @param auc.in.legend Logical. If \code{TRUE} add AUC to legend.
#' @param brier.in.legend Logical. If \code{TRUE} add Brier score to
#'     legend.
#' @param add logical. If \code{1L} add lines to an existing plot.
#' @param ... Used for additional control of the subroutines: plot,
#'     axis, lines, legend, addtable2plot. See \code{\link{SmartControl}}.
##' @examples
##' ## binary
##' set.seed(18)
##' if (requireNamespace("randomForest",quietly=TRUE)){
##' library(randomForest)
##' library(prodlim)
##' bdl <- sampleData(40,outcome="binary")
##' bdt <- sampleData(58,outcome="binary")
##' bdl[,y:=factor(Y)]
##' bdt[,y:=factor(Y)]
##' fb1 <- glm(y~X1+X2+X3+X4+X5+X6+X7+X8+X9+X10,data=bdl,family="binomial")
##' fb2 <- randomForest(y~X1+X2+X3+X4+X5+X6+X7+X8+X9+X10,data=bdl)
##' xb <- Score(list("glm"=fb1,"rf"=fb2),y~1,data=bdt,
##'             plots="roc",metrics=c("auc","brier"))
##' plotROC(xb,brier.in.legend=1L)
##'
##' # with cross-validation
##' \dontrun{
##' xb3 <- Score(list("glm"=fb1,"rf"=fb2),y~1,data=bdl,
##'             plots="roc",B=3,split.method="bootcv",
##'             metrics=c("auc"))
##' }
##' }
##' ## survival
##' set.seed(18)
##' library(survival)
##' sdl <- sampleData(40,outcome="survival")
##' sdt <- sampleData(58,outcome="survival")
##' fs1 <- coxph(Surv(time,event)~X3+X5+X6+X7+X8+X10,data=sdl,x=TRUE)
##' fs2 <- coxph(Surv(time,event)~X1+X2+X9,data=sdl,x=TRUE)
##' xs <- Score(list(model1=fs1,model2=fs2),Hist(time,event)~1,data=sdt,
##'             times=5,plots="roc",metrics="auc")
##' plotROC(xs)
##' ## competing risks
##' data(Melanoma)
##' f1 <- CSC(Hist(time,status)~age+sex+epicel+ulcer,data=Melanoma)
##' f2 <- CSC(Hist(time,status)~age+sex+logthick+epicel+ulcer,data=Melanoma)
##' x <- Score(list(model1=f1,model2=f2),Hist(time,status)~1,data=Melanoma,
##'             cause=1,times=5*365.25,plots="roc",metrics="auc")
##' plotROC(x)
#' @export
plotROC <- function(x,
                    models,
                    times,
                    xlab="1-Specificity",
                    ylab="Sensitivity",
                    col,
                    lwd,
                    lty=1,
                    cex=1,
                    pch=1,
                    legend=TRUE,
                    auc.in.legend=TRUE,
                    brier.in.legend=FALSE,
                    add=FALSE,
                    ...){
    if (is.null(x$ROC))
        stop("Object has no information for ROC curves.\nYou should call the function \"riskRegression::Score\" with plots=\"ROC\".")
    model=FPR=TPR=NULL
    cbbPalette <- c("#000000", "#E69F00", "#56B4E9", "#009E73", "#F0E442", "#0072B2", "#D55E00", "#CC79A7")
    pframe <- x$ROC$plotframe
    if (x$response.type!="binary"){
        if (missing(times)){
            tp <- max(pframe[["times"]])
            if (length(unique(pframe$times))>1)
                warning("Time point not specified, use max of the available times: ",tp)
        } else{ ## can only do one time point
            tp <- times[[1]]
            if (!(tp%in%unique(pframe$times)))
                stop(paste0("Requested time ",times[[1]]," is not in object"))
        }
        pframe <- pframe[times==tp]
    }else tp <- NULL
    if (!missing(models)){
        if (!all(models%in% pframe[,unique(model)]))
            stop(paste0("Cannot identify model names.\nRequested models: ",paste(models,collapse=", "),"\n",
                        "Available models: ",paste(pframe[,unique(model)],collapse=", ")))
        pframe <- pframe[model%in%models]
        ## user's order
        pframe[,model:=factor(model,levels=models)]
    }else{
        if (length(x$null.model)>0){
            pframe <- pframe[model!=x$null.model]
        }
        models=unique(pframe$model)
    }
    setkey(pframe,model)
    mm <- unique(pframe$model)
    lenmm <- length(mm)
    if(missing(col)) col <- rep(cbbPalette,length.out=lenmm)
    names(col) <- mm
    if(missing(lwd)) lwd <- 3
    lwd <- rep(lwd,length.out=lenmm)
    names(lwd) <- mm
    pch <- rep(pch,length.out=lenmm)
    names(pch) <- mm
    if(missing(lwd)) lty <- 1
    lty <- rep(lty,length.out=lenmm)
    names(lty) <- mm
    lines.DefaultArgs <- list(pch=pch,cex=cex,lwd=lwd,type="l",col=col,lty=lty)
    # {{{ legend
    if (is.character(legend[[1]])|| legend[[1]]==TRUE){
        legend.data <- getLegendData(object=x,
                                     models=models,
                                     times=tp,
                                     auc.in.legend=auc.in.legend,
                                     brier.in.legend=brier.in.legend,
                                     drop.null.model=TRUE)
        if (is.character(legend))
            legend.text <- legend
        else
            legend.text <- unlist(legend.data[,1])
        nrows.legend <- NROW(legend.data)
        if (nrows.legend==1){
            legend.lwd <- NA
        }else{
            legend.lwd <- lwd
        }
        legend.DefaultArgs <- list(legend=legend.text,
                                   lwd=legend.lwd,
                                   col=col,
                                   ncol=1,
                                   lty=lty,
                                   cex=cex,
                                   bty="n",
                                   y.intersp=1,
                                   x="bottom",
                                   title="")
        if (NCOL(legend.data)>1){
            addtable2plot.DefaultArgs <- list(yjust=1.18, cex=cex, table=legend.data[,-1,drop=FALSE])
        }else{
            addtable2plot.DefaultArgs <- NULL
        }
    }else{
        legend.DefaultArgs <- NULL
        addtable2plot.DefaultArgs <- NULL
    }
    # }}}
    plot.DefaultArgs <- list(x=0,y=0,type = "n",ylim = c(0,1),xlim = c(0,1),ylab=ylab,xlab=xlab)
    axis1.DefaultArgs <- list(side=1,las=1,at=seq(0,1,.25))
    axis2.DefaultArgs <- list(side=2,las=1,at=seq(0,1,.25))
    control <- prodlim::SmartControl(call= list(...),
                                     keys=c("plot","lines","legend","addtable2plot","axis1","axis2"),
                                     ignore=NULL,
                                     ignore.case=TRUE,
                                     defaults=list("plot"=plot.DefaultArgs,
                                                   "lines"=lines.DefaultArgs,
                                                   "legend"=legend.DefaultArgs,
                                                   "addtable2plot"=addtable2plot.DefaultArgs,
                                                   "axis1"=axis1.DefaultArgs,
                                                   "axis2"=axis2.DefaultArgs),
                                     forced=list("plot"=list(axes=FALSE),
                                                 "axis1"=list(side=1),"axis2"=list(side=2)),
                                     verbose=TRUE)
    if (add==0L) {do.call("plot",control$plot)
        if (is.null(control$axis1$labels)){
            control$axis1$labels <- paste(100*control$axis1$at,"%")
        }
        if (is.null(control$axis2$labels)){
            control$axis2$labels <- paste(100*control$axis2$at,"%")
        }
        do.call("axis",control$axis1)
        do.call("axis",control$axis2)
    }
    if (is.character(legend[[1]]) || legend[[1]]==TRUE){
        legend.coords <- do.call("legend",control$legend)
        if (!is.null(addtable2plot.DefaultArgs)){
            if (is.null(control$addtable2plot[["x"]]))
                control$addtable2plot[["x"]] <- legend.coords$rect$left+legend.coords$rect$w
            ## strange error: $y does not work as yjust is matched, thus use [["y"]]
            if (is.null(control$addtable2plot[["y"]]))
                control$addtable2plot[["y"]] <- legend.coords$rect$top-legend.coords$rect$h
            do.call(plotrix::addtable2plot,control$addtable2plot)
        }
    }
    abline(a=0,b=1,col="gray77",lwd=3)
    pframe[,{thisline <- control$line;
        thisline$col=thisline$col[[as.character(model[1])]];
        thisline$lwd=thisline$lwd[[as.character(model[1])]];
        thisline$lty=thisline$lty[[as.character(model[1])]];
        thisline$pch=thisline$pch[[as.character(model[1])]];
        thisline$x=c(0,FPR,1);
        thisline$y=c(0,TPR,1);
        do.call("lines",thisline)},by=model]
    invisible(x)
}

#----------------------------------------------------------------------
### plotROC.R ends here

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riskRegression documentation built on Jan. 13, 2021, 11:12 a.m.