[R] matrix exponential: M^0

[Trenkler, Dietrich]

> -----Original Message-----
> From:	Federico Calboli 
> Sent:	Tuesday, January 20, 2004 5:40 PM
> To:	r-help
> Subject:	[R] matrix exponential: M^0
> 
> I would like to ask why the zeroeth power of a matrix gives me a matrix
> of ones rather than the identity matrix:
> 
> > 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.
	[Dietrich Trenkler]  M^0 means appying ^0 to each element of M.
	Matrix multiplication can be achieved by A%*%B. In this way A%*%A
	is not the same as A^2.

	Dietrich