You should be looking at the ifelse function. Ihe if and else
constructs are not appropriate for recoding because they do not return
vectors.
Much easier than all that folderol would be:
df$Aggregation <- ifelse( df$Number>1, "School", "Solitary")
On May 4, 2009, at 12:31 PM, barbara horta e costa wrote:
Hi everyone,
Do you know how to apply a If command to a vector in a data.frame,
creating
a new column?
Example: If one species has "1" value in the Abundance column then
it is
"Solitary". If the abundance is higher than 1, is "School".
I did:
aggregationFunction <-function(x){
(if (x>1) a<- 'School'
else a<- 'Solitary')
return (a)
}
Then:
Aggregation <- lapply (df$Number, aggregationFunction )
Then:
df <- data.frame (df, Aggregation)
And I got this error:
Error in data.frame(df, Aggregation) :
arguments imply differing number of rows: 2576, 1
Can you help me doing this function to a vector? Ive tried to find
this
question and the answer online but I couldn't.
I tried also only with if but it is only for 1 length and the error
was:
the condition has length > 1 and only the first element will be used
This question seemed easy in the beginning but I was not successful.
Thanks a lot for helping me.
Barbara
--
Bárbara H. Costa
Marine Biologist Researcher
SCIAENA - Marine Sciences and Cooperation
www.sciaena.org
bco...@ispa.pt
barbarahco...@gmail.com
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