I generated this graph with the below script. But how could I subscript the "10" in PM10, "2" in SO2, and"2" in NO2?
I tried levels(df$variable) <- c("PM[10]","SO[2]", "NO", "NO[2]")
, but does not work.
Can anyone help? Thank you!
variable <- c("PM10","SO2","NO","NO2")
coef <- c(10,20,30,40)
coef_lb <- c(-5,10,23,27)
coef_ub <- c(20,39,39,50)
df <- as.data.frame(cbind(variable, as.numeric(coef),as.numeric(coef_lb),as.numeric(coef_ub)))
df$variable <- factor(df$variable,levels=c("PM10","SO2","NO","NO2"))
levels(df$variable) <- c("PM[10]","SO[2]", "NO", "NO[2]")
library(ggplot2)
#ggplot 95%CI
BWplot <- ggplot(data=df,aes(x=variable,y=coef))
BWplot <- BWplot + geom_pointrange(aes(ymin=coef_lb,ymax=coef_ub))
BWplot <- BWplot + geom_point()
BWplot <- BWplot + scale_y_continuous(limits=c(-110, 110),breaks=seq(-100, 100, by = 20))
BWplot <- BWplot + xlab("Air pollutant")
BWplot <- BWplot + ylab("Mean change")
BWplot <- BWplot + geom_hline(yintercept=0,alpha=0.5)
BWplot
You want to name the axis in the ggplot definitions. This is not possible at the position where you do it now where you are defining a new name (as a string) for the levels. What happens now is that PM[10] will be recognised and read as a string.
Add this to your ggplot script. This defines the x-axis ticks that you have as a discrete scale:
Have fun.
With thanks to Alexwhan it can also be written as:
Which is even easier.