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combining matrices

3 messages · Marten Winter, Richard M. Heiberger, Peter Ehlers

Marten Winter
# 
Heja,

I hope someone is still there to help me:

How can I somehow merge/combine matrices to get such a result:

Matrix A

A B
x1 1 0
x2 1 1

Matrix B

C D
x3 1 0
x4 0 1

Resulting Matrix?


A B C D
x1 1 0 0 0
x2 1 1 0 0
x3 0 0 1 0
x4 0 0 0 1


Does anyone see this probably obvious solution with R how to do this?
Sorry if this question is silly...it's too hot here to think properly ;O)

Thanks!
cheers
Marten
Peter Ehlers
#
On 2011-04-21 07:03, Marten Winter wrote:
If you don't need this very often or very general, then use

  mat <- diag(0,4)
  mat[1:2, 1:2] <- A
  mat[3:4, 3:4] <- B
  mat

If you do need more flexibility, you could use the 'assist'
package's function bdiag() which handles block-diagonal
matrices:

  require(assist)
  mat <- bdiag(list(A,B))

Peter Ehlers