calculating std err (SEM)?
"JRG" <loesljrg at accucom.net> writes:
On 1 Mar 02, at 16:44, Peter Dalgaard BSA wrote:
"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.
Would that perhaps be sd(x,na.rm=TRUE)/sqrt(sum(!is.na(x))) ?
Um. Yes.
On the other hand, I didn't say *what* it killed, did I? ;-)
-p
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 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._