Christof,

This isn't quite what you asked for, but perhaps you will find it useful.
You could save the conditions by putting them in a function.
Then you could apply that function to any data frame with the reference 
variables.

For example,

check.conditions <- function(df) {
        cbind(a=df$day > 100, b=df$val < 50, c=df$year==2012)
        }

mydf <- data.frame(day=c(20, 50, 100, 70, 80, 130), val=c(1, 7, 70, 20, 
55, 30), year=2011:2016)

check.conditions(mydf)

         a     b     c
[1,] FALSE  TRUE FALSE
[2,] FALSE  TRUE  TRUE
[3,] FALSE FALSE FALSE
[4,] FALSE  TRUE FALSE
[5,] FALSE FALSE FALSE
[6,]  TRUE  TRUE FALSE

Jean



Christof Kluß <ckluss@email.uni-kiel.de> wrote on 07/02/2012 12:04:40 PM:

> Hi
> 
> how would you save conditions like
> 
> a = "day > 100"; b = "val < 50"; c = "year == 2012"
> 
> in a list? I like to have variables like "day", "val", "year" and a list
> of conditions list(a,b,c). Then I want to check if a & b & c is true or
> if a | b | c is true or similar things.
> 
> Greetings
> Christof

	[[alternative HTML version deleted]]

