Re: [R] Finding solution set of system of linear equations.

From: dslowik <dslowik_at_tellink.net>
Date: Sun, 22 May 2011 16:09:18 -0700 (PDT)

Thanks Robert. That all seems to work. I also found the MASS::Null() function that gives the null space for the matrix(transpose) given as argument. I am still trying to appreciate the math behind the Moore-Penrose inverse matrix. If you have any suggestions for understanding how to use R to solve these kinds of systems, please send me the pointer.

 I think the R documentation for solve() should state right up front that it only solves non-singular systems, and it should point me to MASS::ginv() and how to use it to solve this obvious kind of problem. Better, there could be a generalized solve() which produces a particular solution, the null space, image space (basis thereof). This other solution (using ginv() and giA%*%A - I for the kernel) seems deeply embedded in a particular solution technique (and should be available), but the generalized solve_lin_sys(), as I suggested, seems generally quite useful..

Don

--
View this message in context: http://r.789695.n4.nabble.com/Finding-solution-set-of-system-of-linear-equations-tp3541490p3542930.html
Sent from the R help mailing list archive at Nabble.com.

______________________________________________
R-help_at_r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Received on Mon 23 May 2011 - 00:38:03 GMT

This quarter's messages: by month, or sorted: [ by date ] [ by thread ] [ by subject ] [ by author ]

All messages

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Mon 23 May 2011 - 04:40:09 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.

list of date sections of archive