[R] Another simple q - removing negative values

[Peter Dalgaard]

Michael Hopkins <michael.hopkins at hopkins-research.com> writes:

> Sorry folks but again I have failed in my understanding of how to do a very
> simple thing.  I've read the various texts and searched the help archives
> but no positive result so far.
> 
> I want to remove all the rows in a data frame where one of the variables has
> negative values.  In approx Stata pseudocode:
> 
>    drop _all, if( x < 0 )
> 
> Please either point me to relevant sections of the docs or supply me with
> solution - I'm sure it's very simple.

There are variations:

d1 <- subset(d, x < 0)

d1 <- d[d$x < 0,]
d1 <- d[d$x < 0 & !is.na(d$x),] # essentially same as subset()

-- 
   O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
 (*) \(*) -- University of Copenhagen   Denmark          Ph:  (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)                  FAX: (+45) 35327907