[R] Adding vertical line to histogram and qplot "stacked" plot

[Duncan Murdoch]

On 1/29/2009 2:03 PM, Jason Rupert wrote:
> R-users it appears I am leaning on your knowledge once again.  Is there any way to add a vertical line to a histogram and qplot "stacked" plot?  Here is my current attempt:
>  
> "qplot" approach attempt:
> qplot(Run, data = data_dataframe, breaks = breaks, fill = Temperature, main = short_title) + scale_x_continuous("Data") + scale_y_continuous("Freq") +  scale_fill_discrete("Temperature") + scale_fill_manual(values = c(LOW = "blue", AMB ="black", HIGH = "red")) +  geom_abline(v = HighVal, col = "dodgerblue3", lty="dotdash") 
>  
>  
> "hist" approach attempt:
> hist(data_dataframe, breaks = breaks,  col = "dodgerblue3", xlab="Data", freq = TRUE, main="") +abline(v = HighVal, col = "dodgerblue3", lty="dotdash")   
>  


Are you using ggplot2?  It uses that notation of adding elements to a 
plot.  Classic graphics doesn't, so you would just give the different 
commands separately on each line, e.g.

hist(data_dataframe, breaks = breaks,  col = "dodgerblue3", xlab="Data", 
freq = TRUE, main="")

abline(v = HighVal, col = "dodgerblue3", lty="dotdash")