I am trying to plot some data over years with two y-axes in R. However, whenever I try to include a legend, the the legend dominates my plot. When I use solutions suggested elsewhere like keyword
and/or using the cex
argument, suggested in another post here, it either becomes unreadable or is still too big.
Here is my example with randomly generated data:
#Create years
year.df <- seq(1974, 2014, 1)
# Create y-axis data
set.seed(75)
mean1 <- rnorm(length(year.df), 52.49, 0.87)
mean2 <- rnorm(length(year.df), 52.47, 0.96)
#Create dataframe
df <- data.frame(cbind(year.df, mean1, mean2))
I want a second y-axis, the difference of the two means over the years
df$diff <- abs(df$mean1 - df$mean2)
When I plot using the code below to create two y-axes:
par(mfrow=c(1,1), mar=c(5.1,4.1,4.1,5.1))
with(df, plot(year.df, mean1, type = "l", lwd=4, xlab="Year", ylab="Mean", ylim=c(48,58)))
with(df, lines(year.df, mean2, type = "l", col="green", lwd=4))
par(new=TRUE)
with(df, plot(year.df, diff, type="l", axes=FALSE, xlab=NA, ylab=NA, col="red", lty=5, ylim=c(0,10)))
axis(side = 4)
mtext(side = 4, line = 3, "Annual Difference")
legend("topleft",
legend=c("Calculated", "MST", "Diff"),
lty=c(1,1,5), col=c("black", "green", "red"))
When I use the cex=0.5
argument in the legend()
, it starts to become unreadable:
Is there a way to format my legend in a clear, readable manner? Better than what I have?