[R] R: determination of number of entries in list elements

Guazzetti Stefano Stefano.Guazzetti at ausl.re.it
Fri May 19 12:21:02 CEST 2006


You need lapply or sapply
for example:

sapply(yourlist, length)
then you can do
subset(yourlist, sapply(yourlist, length) > yourlength) 

Stefano

   >-----Messaggio originale-----
   >Da: r-help-bounces at stat.math.ethz.ch
   >[mailto:r-help-bounces at stat.math.ethz.ch]Per conto di Benjamin Otto
   >Inviato: 19 May, 2006 12:10
   >A: R-Help
   >Oggetto: [R] determination of number of entries in list elements
   >
   >
   >Hi,
   >
   >is there some elegant way to determine the number of 
   >components stored in
   >each list element?
   >
   >Example:
   >
   >The list:
   >---------
   >> list
   >
   >$Elem1
   >[1] A B C
   >
   >$Elem1
   >[1] D
   >
   >$Elem1
   >[1] E F
   >
   >Then normal command "length(list)" would return 3. But I 
   >would like some
   >command return the array of the single element lengths like
   >
   >[1] 3 1 2
   >
   >so I can afterwards get my list subset with only entries 
   >which have a
   >certain amount of components bigger or lower than a certain 
   >threshold.
   >
   >regards
   >
   >Benjamin
   >
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