ll probably have to be a matrix of characters. There you go from
> a 3×4 matrix to a 3×2 matrix. What do you want in case of Barts 2×2
> matrix? A 3×1 or 1×3 matrix? And in a more general case?
>
> Best regards
>
> Frede
>
>
> Sendt fra Samsung mobil
>
> Oprindelig
delig meddelelse
Fra: carol white
Dato:19/06/2014 15.18 (GMT+01:00)
Til: Bart Kastermans
Cc: r-help@r-project.org
Emne: Re: [R] extract a subset of non-contiguous elements of a matrix
tm.1=rbind(c(1,-3,2,-4), c(1,-3,2,-4),c(1,-3,2,-4))
> which(tm.1 > 0, arr.ind=TRUE)
row col
[1,
e
Dato:19/06/2014 15.18 (GMT+01:00)
Til: Bart Kastermans
Cc: r-help@r-project.org
Emne: Re: [R] extract a subset of non-contiguous elements of a matrix
 tm.1=rbind(c(1,-3,2,-4), c(1,-3,2,-4),c(1,-3,2,-4))
> which(tm.1 > 0, arr.ind=TRUE)
    row col
[1,]Â Â 1Â Â 1
[2,]Â Â 2Â Â
15.18 (GMT+01:00)
Til: Bart Kastermans
Cc: r-help@r-project.org
Emne: Re: [R] extract a subset of non-contiguous elements of a matrix
tm.1=rbind(c(1,-3,2,-4), c(1,-3,2,-4),c(1,-3,2,-4))
> which(tm.1 > 0, arr.ind=TRUE)
row col
[1,] 1 1
[2,] 2 1
[3,] 3 1
[4,] 1 3
[5,] 2
On 19 Jun 2014, at 15:16, carol white wrote:
> tm.1=rbind(c(1,-3,2,-4), c(1,-3,2,-4),c(1,-3,2,-4))
>
> > which(tm.1 > 0, arr.ind=TRUE)
> row col
> [1,] 1 1
> [2,] 2 1
> [3,] 3 1
> [4,] 1 3
> [5,] 2 3
> [6,] 3 3
>
> so the answer should have the elements of tm.1 wi
 tm.1=rbind(c(1,-3,2,-4), c(1,-3,2,-4),c(1,-3,2,-4))
> which(tm.1 > 0, arr.ind=TRUE)
    row col
[1,]Â Â 1Â Â 1
[2,]Â Â 2Â Â 1
[3,]Â Â 3Â Â 1
[4,]Â Â 1Â Â 3
[5,]Â Â 2Â Â 3
[6,]Â Â 3Â Â 3
so the answer should have the elements of tm.1 with the following indexes
1,1 1,3
2,1 2,3
3
If you give an example of input and desired output I can think about this. But
at this
point I do not understand what you want. In the example I gave the positive
elements do
not form a submatrix in any way I can think of.
On 19 Jun 2014, at 15:04, carol white wrote:
> well it gives a vector
This _was_ in the answer you got, but to clarify things, perhaps try this:
(M <- matrix(1:9,3,3))
(ix <- rbind(c(3,2),c(1,3)))
M[3,2]
M[1,3]
M[ix]
-pd
On 19 Jun 2014, at 14:12 , carol white wrote:
> The extracted values don't form a matrix and that's the question how to
> extract because whic
The extracted values don't form a matrix and that's the question how to extract
because which returns the indexes? that is, from
1,1
2,1
1,2
how to retrieve values?
Or if at the position 2,1, there is a negative value, how to retrieve
1,1
1,2
Carol
On Thursday, June 19, 2014 1:29 PM, Bart
On 19 Jun 2014, at 13:19, carol white wrote:
> Hi,
> Is there a way to extract a subset of non-contiguous elements of a matrix
> elegantly and with 1 or very few scripts?
>
> Suppose I have a matrix of positive and negative numbers (m) and I want to
> retrieve only the positive number. This I
Hi,
Is there a way to extract a subset of non-contiguous elements of a matrix
elegantly and with 1 or very few scripts?
Suppose I have a matrix of positive and negative numbers (m) and I want to
retrieve only the positive number. This I can do
which(m>0, arr.ind=T) which gives the indices of po
11 matches
Mail list logo
