Question

Happy new year to you all!

I am plotting some graphs and would like to differentiate some plotted lines and points. This is an example of my data and the graph that I am trying to get:

anim <- c(1,2,3,4,5)
var1 <- c(32,36,40,38,39)
var2 <- c(30,31,34,36,38)
surv <- c(0,1,0,1,1)
mydf <- data.frame(anim,var1,var2,surv)
mydf
  anim var1 var2 surv
1    1   32   30    0
2    2   36   31    1
3    3   40   34    0
4    4   38   36    1
5    5   39   38    1

lm.pos1 <- lm(var1~var2,data=mydf)
plot(mydf$var2,mydf$var1,xlab="ave.ear",ylab="rtemp",xlim=c(25,45),ylim=c(25,45))
abline(lm.pos1)
abline(h=37.6,v=0,col="gray10",lty=20)
abline(h=34,v=0,col="gray10",lty=20)

First, I would like to insert the label “37.6°C” on the top horizontal and continuous line and “34.0°C” on the bottom horizontal and broken line.

Second, I would like to colour those individuals (circles) as red if surv=0 (died) or green if surv=1.

Any help would be very much appreciated!

Baz

Answer 1

plot(mydf$var2, mydf$var1, xlab="ave.ear", ylab="rtemp", 
    xlim=c(25,45), ylim=c(25,45), col=c('green', 'red')[surv+1])
abline(lm.pos1)
abline(h=37.6,v=0,col="gray10",lty=20)
text(25,38.1,parse(text='37.6*degree'),col='gray10')
abline(h=34,v=0,col="gray10",lty=20)
text(25,34.5,parse(text='34*degree'),col='gray10')