Hi:
Check the class and dimensions of your objects. If mat1 is either
an eight element numeric vector or a one-row matrix, you should
have no problem:
> mat1 <- 1:8 # vector
> mat2 <- matrix(rnorm(240), nrow =30)
> class(mat1)
[1] "integer"
> class(mat2)
[1] "matrix"
> mat3 <- mat2
> mat3[1, ] <- mat1
> head(mat3, n = 3)
[,1] [,2] [,3] [,4] [,5] [,6]
[1,] 1.00000000 2.0000000 3.0000000 4.0000000 5.0000000 6.0000000
[2,] 0.07651876 -0.8993153 -0.2798143 -0.1728898 0.2953603 -0.2125125
[3,] 0.12433595 0.6025504 0.1784886 0.2304723 0.8189139 1.7240880
[,7] [,8]
[1,] 7.00000000 8.0000000
[2,] -0.08513052 -0.5989580
[3,] -1.78079197 -0.5740252
> class(mat3)
[1] "matrix" # check
> mat1a <- matrix(1:8, nrow = 1) # one row matrix
> class(mat1a)
[1] "matrix"
> dim(mat1a)
[1] 1 8
> mat2[1, ] <- mat1
> class(mat2)
[1] "matrix"
> dim(mat2)
[1] 30 8
> head(mat2, n = 3)
[,1] [,2] [,3] [,4] [,5] [,6]
[1,] 1.00000000 2.0000000 3.0000000 4.0000000 5.0000000 6.0000000
[2,] 0.07651876 -0.8993153 -0.2798143 -0.1728898 0.2953603 -0.2125125
[3,] 0.12433595 0.6025504 0.1784886 0.2304723 0.8189139 1.7240880
[,7] [,8]
[1,] 7.00000000 8.0000000
[2,] -0.08513052 -0.5989580
[3,] -1.78079197 -0.5740252 # check
It's entirely possible that either your mat1 is not a one-row numeric matrix
or your mat2 is not a matrix. Check the class, dimensions, etc.
HTH,
Dennis
On Fri, Jan 29, 2010 at 12:55 PM, anna <[email protected]> wrote:
>
> Hello, I have a matrix mat1 of dim [1,8] and mat2 of dim[30,8], I want to
> replace the first row of mat2 with mat1, this is what I do:
> mat2[1,]<-mat1 but it transforms mat2 in a list I don't understand, I want
> it to stay a matrix...
>
> -----
> Anna Lippel
> --
> View this message in context:
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> Sent from the R help mailing list archive at Nabble.com.
>
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