matrix exponential: M^0

Dear All,

I would like to ask why the zeroeth power of a matrix gives me a matrix
of ones rather than the identity matrix:
Because ^ is not the matrix power. It's the elementwise power.

	-thomas
D<-rbind(c(0,0,0),c(0,0,0),c(0,0,0))
D<-as.matrix(D)
D
     [,1] [,2] [,3]
[1,]    0    0    0
[2,]    0    0    0
[3,]    0    0    0

D^0
     [,1] [,2] [,3]
[1,]    1    1    1
[2,]    1    1    1
[3,]    1    1    1

I would have expected the identity matrix here.

I find the same result with every other square matrix I used.
BTW, I am using R 1.8.1 on Linux Mandrake 9.1

Cheers,

Federico Calboli
--

=================================

Federico C. F. Calboli

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Dipartimento di Biologia
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tel (+39) 051 209 4187
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f.calboli at ucl.ac.uk

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Thomas Lumley			Assoc. Professor, Biostatistics
tlumley at u.washington.edu	University of Washington, Seattle

matrix exponential: M^0

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