p <- c(b=1,RT=1,h=0.1,c=0.1) with(as.list(p),curve(b*(RT-c*N)/(h+RT-c*N),from=0,to=11,ylim=c(0,1),xname="N",col="red",lwd=2)) with(as.list(p),lines(rep((h+RT)/c,2),c(-1,2))) size <- 5 #inch pdf("birth.pdf",width=size,height=size) par(mar=c(0.1,0.1,0.1,0.1),xaxt="n",yaxt="n",ann=F,xaxs="i",yaxs="i") with(as.list(p),curve(b*(RT-c*N)/(h+RT-c*N),from=0,to=11,ylim=c(0,1),xname="N",col="red",lwd=2)) lines(c(10.7,10.7),c(-1,2)) dev.off()