[R] calculating std err (SEM)?

[Peter Dalgaard BSA]

"Kirk R. Wythers" <kwythers at umn.edu> writes:

> Is there a "canned" function in R for finding the standard error of the
> mean? I have tried 
> 
> >  sem <- function(x) c(mean =mean(x),
> +  SEM = stdev(x)/sqrt(length(x)))
> > sem(pnet.lai)
> Error in sem(pnet.lai) : couldn't find function "stdev"
> 
> 
> It looks like there is no stdev function in R

It's sd() (as help.search("deviation") might have told you). Also,
beware of missing values:  sd(x,na.rm=TRUE)/sum(!is.na(x)) is the sure
kill. 

-- 
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)             FAX: (+45) 35327907
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