Re: [R] / Right division.

From: Duncan Murdoch <murdoch_at_stats.uwo.ca>
Date: Wed 27 Jul 2005 - 06:15:15 EST

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



R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Wed Jul 27 06:18:12 2005

This archive was generated by hypermail 2.1.8 : Fri 03 Mar 2006 - 03:34:01 EST