Group
It's unlikely I'm trying this the best way, but I'm trying to create a
data structure from elements like
nNode = 2
nn = vector("list",nNode)
nn[[1]] = list(Node = "1", Connect.up = c(NULL), Connect.down = c(2,3))
nn[[2]] = list(Node = "2", Connect.up = c(1), Connect.down = c(4,5))
.... #( and eventually many more nodes)
NodeList = as.data.frame(nn[[1]])
for(i in 2:nNode) {
NodeList = rbind(NodeList,as.data.frame(nn[[i]]))
}
and is trying to create a data frame with many rows and three columns:
Node, Connect.up,Connect.down
in which the Connect.up and Connect.down columns may be single numbers
or vectors of numbers. The above approach gives an error:
Error in data.frame(Node = "1", Connect.up = NULL, Connect.down = c(2, :
arguments imply differing number of rows: 1, 0, 2
My earlier try by brute force worked fine:
NodeList = as.data.frame(rbind(nn[[1]],nn[[2]]))
> NodeList
Node Connect.up Connect.down
1 1 NULL 2, 3
2 2 1 4, 5
and gives me what I want (many more rows eventually). But I want to do
this generically from the problem context in a procedure so I won't know
up front how many nodes I'll have.
Clearly I'm not understanding how referencing works for lists like I've
created. Can anyone shed light on this?
--
David K Stevens, P.E., Ph.D., Professor
Civil and Environmental Engineering
Utah Water Research Laboratory
8200 Old Main Hill
Logan, UT 84322-8200
435 797 3229 - voice
435 797 1363 - fax
david.stev...@usu.edu
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