Marcelo Laia <marcelolaia <at> gmail.com> writes:
>
> Hi,
>
> I have a data set like this:
>
[snip]
> I need to plot a graph OD over the time for each one mutant with error bars.
>
>
## I put your data in a temporary file, this reads it
x = read.table("tempdata.txt",header=TRUE)
## compute means and standard errors
## (no built-in function for standard error, so create one)
## also see ?aggregate, ?by
means = with(x,tapply(OD,list(Time,Mutant),mean))
se = function(x) sd(x)/sqrt(length(x))
ses = with(x,tapply(OD,list(Time,Mutant),se))
## time vector -- could also be unique(x$Time)
times = as.numeric(rownames(means))
## plot the means
matplot(times,means,type="b",lty=1,col=1:2,pch=1:2)
library(plotrix)
## have to create the x-vector and color-vector "by hand"
## it would be nice if there were a matplotCI, but there
## isn't (yet) ...
plotCI(rep(times,2),means,ses,pch=NA,add=TRUE,
col=rep(1:2,each=nrow(means)))
good luck
Ben Bolker
______________________________________________
R-help@r-project.org mailing list
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.
