OK. How about:
> dfeg <- as.list(data.frame(t(expand.grid(1:2, 3:5))))
> dfeg[["ij"]] <- c("i", "j")
> dfeg
$X1:
[1] 1 3
$X2:
[1] 2 3
$X3:
[1] 1 4
$X4:
[1] 2 4
$X5:
[1] 1 5
$X6:
[1] 2 5
$ij:
[1] "i" "j"
hth. spencer graves
Myers, Brent wrote:
> Thanks for your reply,
>
> Sorry, your suggestion is not quite what's needed.
>
> Expand.grid produces a dataframe having columns i and j and with i*j
records.
>
> I want a list (length i*j) with i,,j pair vectors as list members. In
other words, I want to collapse each observation in the data frame into
a vector, adding the vector to a list.
>
> e.g.
> [[1]]:
> [1] 1 1
>
> [[2]]:
> [1] 1 2
>
> [[3]]:
> [1] i j
>
>
> Thanks very much for trying,
> Brent
>
################################
How about:
> as.list(data.frame(expand.grid(1:2, 3:5)))
$Var1:
[1] 1 2 1 2 1 2
$Var2:
[1] 3 3 4 4 5 5
hope this helps. spencer graves
Myers, Brent wrote:
>>S community,
>>
>>I am using expand.grid to flexibly create a set of cell indexes(i,,j)
from the dimensions of any matrix passed to a function.
>>
>>How can I get the expand.grid output into the form of a list of vectors?
>>
>>e.g list of cell index vectors
>>[[1]]:
>>[1] 1 1
>>
>>[[2]]:
>>[1] 1 2
>>
>>[[3]]:
>>[1] i j
>>
>>Here is my case
>>
>>#Get dimensions of any matrix or array
>>idx.limits <-dim(acube)
>>
>>#Generate the list of (planar) central cell index combinations
>>ccidx <- expand.grid (1:idx.limits[1], 1:idx.limits[2])
>>
>>I can try...
>>ccidx.matrix <- matrix(c(ccidx[[1]], ccidx[[2]]), length(ccidx[[1]]))
>>
>>to get a matrix, and then ...
>>ccidx.list <- apply(ccidx.matrix, 1, c)
>>
>>to collapse along the rows, But c doesn't work as expected. Sum adds
along rows, but concatenate doesn't work that way?
>>
>>D. Brent Myers
>>Research Specialist - Agronomy
>>University of Missouri
>>158 Ag Engineering Building
>>Columbia, MO 65211
>>
>>
>>
>
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