R：图例的位置和图例中线条的长度

Question

I can't set the location of the legend properly, I have tried to play around with xjust and ncol but it still appears in the middle of the graphic.

Can you help it align it to the border (left or right I do not care)?

Moreover is it possible to draw shorter lines in the legend? These appear too long.

 par(mar=c(5,4,4,5)+.1)
 plot(1:109,rnorm(109), type="l",col="blue", lwd=2, 
      main="Compare signal and std deviation MC3 ch44",
      ylab="signal", xlab="locations")
 par(new=TRUE)
 plot(1:109, rnorm(109), ylab="",xlab="", type="l", 
      col="red",xaxt="n",yaxt="n", lwd=2)
 axis(4)
 mtext("std. deviation",side=4,line=3)
 legend("topright",col=c("blue", "red"), lwd=2,
        legend=c("signal","std dev"), cex=0.85, bty="n", xjust=1)

Answer 1

As pointed out in the comments restarting an R session and using

legend("topright",col=c("blue", "red"), lwd=2,
 legend=c("signal","std dev"), cex=0.85, bty="n", xjust=1, seg.len=0.5)

solved my problems.