It works. Thanks Jim. I guess this will be a "lots of coffee" morning kinda day.
jim holtman <[EMAIL PROTECTED]> wrote: What exactly are you trying to do? In
the first case you are making a logical comparison and that is legal for "&".
In the second you are trying to do a logical operation ("&") between two
factors and that operation is not defined. This is what the error message is
saying.
Also you first attempt is probably missing a comma:
node1 <- data.trt[data.trt$stage=="1B" & data.trt$diameter=="=< 4", ]
On Wed, Jun 4, 2008 at 8:10 AM, Philip Twumasi-Ankrah <[EMAIL PROTECTED]>
wrote:
I am trying to define groupings from levels of factor variables and this the
warning message that R give
"& not meaningful for factors".
The nature of my task is this. I have a variable stage which has the levels
(1B, 2A, 2B) - these are the AJCC TNM stages of cancer, and another variable
diameter with factor levels ("=< 4", "4 - 6.5, > 6.5; limit values are
exclusive).
I am trying to define series of groupings based on these variables and others
like them.
My first attempts were;
1. node1 <- data.trt[data.trt$stage=="1B" & data.trt$diameter=="=< 4"]
2. data.trt$stage[data.trt$stage=="1B"]&
data.trt$diameter[data.trt$diameter=="=< 4"]
The second attempt was purely a fishing exercise.
R gave me the waring message:
Warning message:
In Ops.factor(data.trt$stage[data.trt$stage == "1B"],
data.trt$diameter[data.trt$diameter == :
& not meaningful for factors
My question is how do I get round this and by implication is there an
alternative way of defining a logical operation applicable to factors.
Thanks already for the help.
Philip
A Smile costs Nothing
But Rewards Everything
Happiness is not perfected until it is shared
-Jane Porter
[[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.
--
Jim Holtman
Cincinnati, OH
+1 513 646 9390
What is the problem you are trying to solve?
A Smile costs Nothing
But Rewards Everything
Happiness is not perfected until it is shared
-Jane Porter
[[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.
