[R] How to write a Surv object to a csv-file?

[Heinz Tuechler]

Dear All,

trying to write a data.frame, containing Surv objects to a csv-file I get
"Error in dimnames(X) <- list(dn[[1L]], unlist(collabs, use.names = FALSE)) :
   length of 'dimnames' [2] not equal to array extent".

See example below.

May be, I overlooked something, but I expected 
that also data.frames containing Surv objects may be written to csv files.

Is there a better way to write to csv files?

Thanks,

Heinz Tüchler



###   write Surv-object in csv-file
library(survival)
## create example data
soa <- Surv(1:5, c(0, 0, 1, 0, 1))
df.soa <- data.frame(soa)
write.csv(df.soa, 'df.soa.csv')    ## works as I expected
read.csv('df.soa.csv')	            ## works as I expected

df.soa2 <- data.frame(soa, soa2=soa)
write.csv(df.soa2, 'df.soa2.csv')  ## works as I expected
read.csv('df.soa2.csv')            ## works as I expected

char1 <- letters[1:5]
df.soac <- data.frame(soa, char1)
write.csv(df.soac, 'df.soac.csv')  ## generates the following error message:

Error in dimnames(X) <- list(dn[[1L]], unlist(collabs, use.names = FALSE)) :
   length of 'dimnames' [2] not equal to array extent

df.csoa <- data.frame(char1, soa)
write.csv(df.csoa, 'df.soac.csv')  ## generates the following error message:

Error in dimnames(X) <- list(dn[[1L]], unlist(collabs, use.names = FALSE)) :
   length of 'dimnames' [2] not equal to array extent


platform       i386-pc-mingw32
arch           i386
os             mingw32
system         i386, mingw32
status         Patched
major          2
minor          8.0
year           2008
month          11
day            10
svn rev        46884
language       R
version.string R version 2.8.0 Patched (2008-11-10 r46884)
 > sessionInfo()
R version 2.8.0 Patched (2008-11-10 r46884)
i386-pc-mingw32

locale:
LC_COLLATE=German_Austria.1252;LC_CTYPE=German_Austria.1252;LC_MONETARY=German_Austria.1252;LC_NUMERIC=C;LC_TIME=German_Austria.1252

attached base packages:
[1] splines   stats     graphics  grDevices utils     datasets  methods
[8] base

other attached packages:
[1] survival_2.34-1