[R] Exponent of asymmetric matrix

Peter Langfelder peter.langfelder at gmail.com
Wed Nov 10 02:46:35 CET 2010


> the exponent of asymmetric matrix makes me very curious.
> can anyone please explain to me "what will happen if we apply exponent to
> the asymmetric matrix"?

The gates of Hell will open, the world will come to an end, and we
will all perish in a firestorm :)

Sorry, couldn't resist. Exponentiating a non-symmetric (or
anti-symmetric) matrix is no different from exponentiating a symmetric
matrix. For example the matrix T = cbind(c(0, 1), c(-1, 0)), i.e.

     [,1] [,2]
[1,]    0   -1
[2,]    1    0

generates rotations in the xy plane, that is exp(alpha * T) is the
rotation matrix in the xy plane by angle alpha.

Peter



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