R help - Nov 2012 - help with for loop to test for a condition in a vector

I want my for loop to test for the presence of a term in a vector and return
a value to a new vector. I'm not writing it correctly though. Here's
what I
have...
> testfor = letters[1:5]
> x = c("a", "b", "e", "f",
"g")
> result = rep(NA, length(testfor))
> 
> for (i in testfor){
+   v = any(x == testfor[i])
+   result[i] = v
+ }
> 
> result
                a  b  c  d  e 
NA NA NA NA NA NA NA NA NA NA 

I would like to get....
>result
TRUE TRUE TRUE FALSE FALSE

Thanks,
MVS



-----
MVS
====Matthew Van Scoyoc
Graduate Research Assistant, Ecology
Wildland Resources Department & Ecology Center
Quinney College of Natural Resources
Utah State University
Logan, UT
====Think SNOW!


--
View this message in context:
http://r.789695.n4.nabble.com/help-with-for-loop-to-test-for-a-condition-in-a-vector-tp4649213.html
Sent from the R help mailing list archive at Nabble.com.

On Nov 10, 2012, at 2:07 PM, scoyoc wrote:
> I want my for loop to test for the presence of a term in a vector and
return
> a value to a new vector. I'm not writing it correctly though.
Here's what I
> have...
> 
>> testfor = letters[1:5]
>> x = c("a", "b", "e", "f",
"g")
>> result = rep(NA, length(testfor))
>> 
>> for (i in testfor){
> +   v = any(x == testfor[i])
> +   result[i] = v
> + }
>> 
>> result
>                a  b  c  d  e 
> NA NA NA NA NA NA NA NA NA NA 
> 
> I would like to get....
> 
>> result
> TRUE TRUE TRUE FALSE FALSE
> 
Looks like yu want the first of these:

> x %in% testfor
[1]  TRUE  TRUE  TRUE FALSE FALSE
> testfor %in% x
[1]  TRUE  TRUE FALSE FALSE  TRUE 

-- 

David Winsemius, MD
Alameda, CA, USA