File:Binomial distribution cdf.svg

# R source code for Wikipedia SVG plot of Binomial CDF
# by de:User:Sigbert, Feb 2010
 
require("RSvgDevice")

create.binomial.cdf <- function(N, p, colour="black", pch=16) {
 n <- max(length(N),length(p),length(colour),length(pch))
 N <- rep(N,length=n); p <- rep(p,length=n)
 colour <- rep(colour,length=n); pch <- rep(pch,length=n) 

 add.one.series <- function(N, p, colour, pch, maxN) {
   cdf <- pbinom(0:N, N, p)
#   lines(0:N, cdf, type="s", col=colour)
   for (i in 1:N) lines (c(i-1,i), c(cdf[i], cdf[i]), type="s", col=colour)
   lines(c(N,maxN), c(1, 1), type="s", col=colour)
   points(0:N, cdf, col=colour, pch=pch)
 }
 
 par(lwd=1.5, cex=1, mar=c(3.1,2.5,0.5,0.5))
 plot(1, xlim=c(0,max(N)), ylim=c(0,1), type="n", xlab="", ylab="")
 for (i in 1:n)
   add.one.series(N[i],p[i],colour[i],pch[i], max(N))
   
 text = paste("p=",rev(p)," and N=",rev(N),sep="")
 legend(max(N), 0, legend=text, xjust=1, yjust=0,
   pch=rev(pch), lwd=rep(par("lwd"),3), col=rev(colour), y.intersp=1.5, bty="n")
}

devSVG("Binomial_distribution_cdf.svg",width=4,height=3)
create.binomial.cdf(c(40,20,20), c(0.5,0.7,0.5), c("red","green","blue"), c(20,15,18))
dev.off()