methods on missing data
Maciej.Hoffman-Wecker at evotecoai.com wrote:
Hello everybody! I have 2 >issues< concerning methods applied to missing data. I think they're bugs, but who knows.
I don't think so :-)
1. var(NA) returns
Error in var(NA) : missing observations in cov/cor
instead of NA.
Because you didn't tell var() that it should remove missing values, it warns you that there are missing values. If you want to remove them the following gives the answer you expected.
var(NA, na.rm=TRUE)
[1] NA
I expanded the summary-function to my.summary
including SDev, in order to use it with tapply, which crashes
in case of groups with no valid data.
2. is a similar problem. I use tapply with hist. On groups
without valid data it crashes, like hist(as.numeric(c(NA)))
returning
Error in pretty(rx, n = nnb, min.n = 1) : x must be numeric
hist(as.numeric(c(NA)),breaks=c(1,2)) works, as it does not use "pretty".
I know these are very special cases, but unfortunately they kill the whole
process.
Maybe you should check before if your vector contains only NA's, e.g., using is.na() Hope this helps Achim --------------------------- Achim Zeileis Institut f?r Statistik Technische Universit?t Wien -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- 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 _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._