# R/km_combine.R In RPEXE.RPEXT: Reduced Piecewise Exponential Estimate/Test Software

#### Documented in km_combine

```#' Comparing two Kaplan Meier curves in one plot
#'
#' @description The function compares two Kaplan Meier curves in one plot
#'
#' @param x1 Nx2 data matrix,first columen represents survival time of the i-th subject, second column represents censored flag (0 if not censored, 1 if censored)
#' @param x2 Nx2 data matrix,first columen represents survival time of the i-th subject, second column represents censored flag (0 if not censored, 1 if censored)
#' @param pos The position of the legend. Can be 0 or 1. The legend will be
#'    on the topright if set to 0. The legend will be on the bottomleft if set to 1. Default is 0.
#'
#' @importFrom graphics plot
#' @importFrom graphics points
#' @importFrom graphics lines
#' @importFrom graphics title
#' @importFrom graphics legend
#'
#' @return
#' A combined Kaplan Meier curve
#'
#' @export
#'
#' @examples
#' t1 <- c(2,3,4,5.5,7,10,12,15)
#' c1 <- c(0,0,1,0,0,1,0,0)
#' t2 <- c(1,3,5,4,8,10,9,11)
#' c2 <- c(0,0,0,0,1,0,0,0)
#' x1<-cbind(t1,c1)
#' x2<-cbind(t2,c2)
#' km_combine(x1,x2)
#' km_combine(x1,x2,pos=1)
km_combine <- function(x1, x2, pos = 0){

kmout1 <- kmvalue(x1)
kmout2 <- kmvalue(x2)
table1 = kmout1\$table1
table12 = kmout1\$table12
t1 = kmout1\$t1
T1 = kmout1\$T1
xcg1 = kmout1\$xcg
ycg1 = kmout1\$ycg
t2 = kmout2\$t1
T2 = kmout2\$T1
xcg2 = kmout2\$xcg
ycg2 = kmout2\$ycg

# plot Kaplan_Meier
plot(t1, T1, type = "s",xlab="Time", ylab="Estimated survival functions", lty = 2,
col = "blue",ylim = c(0,1))
points(xcg1, ycg1,cex=.8,pch=3, col = "black")

lines(t2, T2, type = "s",xlab="Time", ylab="Estimated survival functions", lty = 2,
col = "red",ylim = c(0,1))
points(xcg2, ycg2,cex=.8,pch=3, col = "black")
title('Kaplan-Meier estimate of survival functions')
if (pos == 0)
position = "topright"
if (pos == 1)
position = "bottomleft"
legend(position,legend=c("Treatment 1","Treatment 2","Censored"),col=c("blue", "red","black"), lty=c(2,2,NA),pch = c(NA,NA,3), cex=0.8)

}
```

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RPEXE.RPEXT documentation built on May 29, 2017, 12:40 p.m.