Ifelse stability problems?

On 2010-12-19 03:50, Luca Meyer wrote:

I am just wondering why what I am showing below might occur.

First I have an x data.frame:

str(x)

'data.frame':   281 obs. of  2 variables:
 $ x1   : Factor w/ 5 levels "A (50-67%)","B (10-20%)",..: 1 2 5 1 2 5 1 2 5 1 ...
 $ x2   : num  33.8 60.2 6 76.8 13.8 9.4 76.9 8 15.1 78.1 ...

I need to check that for each level of factor x1 the values of x2 are (approximately) contained within a given range. In such a case I will print "ok" a third variable, otherwise I will write "err"

ifelse (x$x1 == "A (50-67%)",
    x$check<-ifelse(x$x2<68&x$x2>49,"ok","xxxx"),
    x$check<-x$check
)

[...snip...]

Can anyone explain why this might occur?

You have a bit of a logic problem in your ifelse;
(look at your x$check after each of your ifelse()s);
try it this way:

x$check <- NA
x$check <- ifelse (x$x1 == "A (50-67%)",
   ifelse(x$x2<68&x$x2>49,"ok","xxxx"),
   x$check
)

etc.

Peter Ehlers

Thanks,
Luca


Luca Meyer
www.lucameyer.com
IBM SPSS Statistics release 19.0.0
R version 2.12.1 (2010-12-16)
Mac OS X 10.6.5 (10H574) - kernel Darwin 10.5.0