I do not quite follow your post but here are some suggestions.
1) You can the na.strings argument to simplify things
df - read.delim(file=lala.txt, na.strings=- )
2) If you can count the number of metastasis per row first, then find
the rows with zero sum.
met.cols - c(11,12,14,21,23,24) # metastasis columns
number.of.met - rowSums( mela[ , met.cols ] == - )
have.no.met - which( number.of.met == 0 )
mela.no.met - mela[ have.no.met , ]
If you had coded your - as NA during read in then, the second line
needs to be changed to
number.of.met - rowSums( is.na( mela[ , met.cols ] ) )
or simply use complete.cases
met.cols - c(11,12,14,21,23,24) # metastasis columns
mela.no.met - mela[ which( complete.cases(mela[ , met.cols]) ) , ]
3) If you name your columns in a systematic fashion, then you can easily
extract and specify those columns. For example if your columns were
named
cn - c( age, colon.met, PSA.level, prostate.met, gender,
hospitalisation.days, status, liver.met, ethnicity)
Then you can extract those names ending with .met as
met.cols - grep( \\.met$, cn )
met.cols
[1] 2 4 8
Regards, Adai
On Sun, 2005-11-13 at 18:40 +0100, [EMAIL PROTECTED] wrote:
Hi i'm a french medical student,
i have some data that i import from excel. My colomn of the datafram
are the localisations of metastasis. If there is a metatsasis there is
the symbol _. i want to exclude the row without metastasis wich
represent the NA data.
so, i wrote this
mela is the data fram
mela1=ifelse(mela[,c(11:12,14:21,23,24)]==_,1,0) # selection of the
colomn of metastasis localisation
mela4=subset(mela3,Skin ==0 s.c == 0 Mucosa ==0 Soft.ti ==0
Ln.peri==0 Ln.med==0 Ln.abdo==0 Lung==0 Liver==0
Other.Visc==0 Bone==0 Marrow==0 Brain==0 Other==0) ## selection
of the row with no metastasis localisation
nrow(mela4)
but i dont now if it is possible to make the same thin as
ifelse(mela3,Skin s.c== 0, 0,NA) with more than colomn and after to
exclude of my data the Na with na.omit.
The last question is how can i omit only the row which are NA value for
the colomn metastasis c(11:12,14:21,23,24))
Thank you for your help
Bertrand billemont
[[alternative text/enriched version deleted]]
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