[R] / Right division.

Duncan Murdoch murdoch at stats.uwo.ca
Tue Jul 26 22:15:15 CEST 2005

On 7/26/2005 4:02 PM, nwew wrote:
> Dear R gurus.
> Is there an R function equivalent to octaves / (Right division)
> withouth forming the inverse of Y' using solve ?
> [snip - from octave docu]
>  Right division.  This is conceptually equivalent to the expression
>           (inverse (y') * x')'
>      but it is computed without forming the inverse of Y'.
>      If the system is not square, or if the coefficient matrix is
>      singular, a minimum norm solution is computed.

If x is a vector, I think it's solve(t(Y), x).  If x is stored as a 1xn 
matrix, you'd use t(solve(t(Y), t(x)).

If you're trying to do multiple operations at once, you probably need to 
use the second form.

Duncan Murdoch

More information about the R-help mailing list