Newbie hung up with matrices
On Fri, 16 May 2003 rwatkins at cornerstonelp.com wrote:
I just started learning R. I'm trying to use the Help and the downloadable
manuals. I am stuck on trying to multiply matrices. Can anyone please
supply a couple of lines of code that I can plug into a fresh console to see
how a double precision (1x3) matrix is multiplied by a double precision
(3x3) matrix? I keep getting an error message,"Error in x%*%A: requires
numeric matrix/vector arguments".
I have some VBA and VB experience (thus a little Object Oriented
programming experience), am I right in beliving that I am not "dimensioning"
correctly? I have been trying the following example:
A<-matrix
A<-read.csv("test33.csv"), where the data is
A,B,C
1,4,7
2,5,8
3,6,9
You've forgotten header=TRUE, if you don't want A,B,C to be part of your matrix. R comes with a Data Import/Export Manual: please consult it.
Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595