You do know that the median is defined as the point with half the values above it and half below it? For even sample sizes it will always be 50%.
Your function is not working because you used the ifelse() function instead of the programming command if() else: > ?Control # Note the capital "C" > ?ifelse But you do not understand basic R so you should spend some time using a tutorial before you try to write functions. > set.seed(42) # Set random number seed > x <- rnorm(100) # Draw 100 random normal values with mean=0 and sd=1 > sum(x > median(x))/length(x)*100 # Compute the % greater than the median [1] 50 ------------------------------------- David L Carlson Department of Anthropology Texas A&M University College Station, TX 77840-4352 -----Original Message----- From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of Indhira, Anusha Sent: Thursday, October 20, 2016 3:26 AM To: r-help@r-project.org Subject: [R] need help in customising function in stat_summary function ggplot2 Hi, I would like to print percentage of points in a group which are greater than median value in boxplot. I have tried below code but it always prints zero in the graph. Can you let me know, how to modify code to get desired result? perc.greaterthan.median <- function(x){ cnt = 0 for(i in 1:length(x)){ ifelse(x[i] > median(x),cnt+1,cnt) } return(c(y = median(x)*1.7, label = round((cnt/length(x))*100,2))) } ggplot(st_chg_51, aes(x=factor(st_dv), P3))+ #label=rownames(st_chg_51))) + geom_boxplot(fill = "grey80", colour = "#3366FF") + stat_summary(fun.data = perc.greaterthan.median, geom = "text", fun.y = median) + theme_bw()+theme(axis.text = element_text(angle = 90, hjust = 1)) Why does cnt in the function doesn't get incremented in the loop? Thanks, Anusha This e-mail (including attachments) contains contents owned by Rolls-Royce plc and its subsidiaries, affiliated companies or customers and covered by the laws of England and Wales, Brazil, US, or Canada (federal, state or provincial). The information is intended to be confidential and may be legally privileged. If you are not the intended recipient, you are hereby notified that any retention, dissemination, distribution, interception or copying of this communication is strictly prohibited and may subject you to further legal action. Reply to the sender if you received this email by accident, and then delete the email and any attachments. [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
