Thanks for the comment, I didn't think about this thorougly.
Le 3/10/2011 12:54, Duncan Murdoch a écrit :
On 11-03-10 5:54 AM, Ivan Calandra wrote:
Try with double "== "instead:
ifelse(val3 == "Monthly", val<- val1, val<- val2)
That might work, but it is not how you should do it. (It should work
if val3 has a single entry, but will do strange things if val3 is a
vector:
> val3 <- c("Monthly", "Daily")
> ifelse(val3 == "Monthly", val<- 1, val<- 2)
[1] 1 2
> val
[1] 2
The ifelse() function does a vectorized test, and picks results from
the two vector alternatives. Vincy wants a simple logical if, which
can be computed in a few different ways:
val <- if(val3 == "Monthly") val1 else val2
or
if (val3 == "Monthly") val <- val1
else val <- val2
For a simple calculation like this I'd probably use the former; if the
calculation got more complex I'd prefer the latter.
Duncan Murdoch
Single "=" is for setting arguments within a function call. If you want
to test equality, then double "==" is required.
See ?"=="
HTH,
Ivan
Le 3/10/2011 11:45, Vincy Pyne a écrit :
Dear R helpers
Suppose
val1 = c(10, 20, 35, 80, 12)
val2 = c(3, 8, 11, 7)
I want to select either val1 or val2 depending on value of third
quantity val3.
val3 assumes either of the values "Monthly" or "Yearly".
If val3 = "Monthly", then val = val1 and if val3 = "Yearly", then
val = val2.
I tried the ifelse statement as
ifelse(val3 = "Monthly", val = val1, val2)
I get following error
ifelse(val3 = "Monthly", val = val1, val2)
Error in ifelse(val3 = "Monthly", val = val1, val2) :
unused argument(s) (val3 = "Monthly", val = val1)
val
Error: object 'val' not found
Kindly guide.
Regards
Vincy
[[alternative HTML version deleted]]
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
--
Ivan CALANDRA
PhD Student
University of Hamburg
Biozentrum Grindel und Zoologisches Museum
Abt. Säugetiere
Martin-Luther-King-Platz 3
D-20146 Hamburg, GERMANY
+49(0)40 42838 6231
ivan.calan...@uni-hamburg.de
**********
http://www.for771.uni-bonn.de
http://webapp5.rrz.uni-hamburg.de/mammals/eng/1525_8_1.php
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
