Hello,
I am a newcomer to R and therefore apologize for posting such a
basic question. I am
trying to multiply 2 matrices t(X1)%*%X1, where t(X1) is:
1 2 3 4 5 8 12 13 20 24 26 27 31 33 34 36 37 40 41 42 45 46
47 48 49
ones 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1
Shadow 0 1 1 1 1 1 1 1 0 1 1 1 1 0 1 0 1 0 1 1
0 1 0 1 0
However, when I try to perform this operation, I obtain:
Error in t(X1) %*% X1 : requires numeric matrix/vector arguments
Can someone please tell me what I seem to be doing wrong? thanks.
Sincerely,
Murali Kuchibhotla
Murali Kuchibhotla
Department of Economics
Iowa State University
Office:75,Heady
Phone:515-294-5452
[[alternative HTML version deleted]]
On 17/07/2008 9:47 PM, Murali K wrote:> Hello, > I am a newcomer to R and therefore apologize for posting such a > basic question. I am > trying to multiply 2 matrices t(X1)%*%X1, where t(X1) is:It's hard to say for sure, but it looks as though X1 really isn't a numeric matrix. The "ones" and "Shadow" entries on the left look like character or factor data. To find out what X1 is, you can run str(X1). Duncan Murdoch> > > 1 2 3 4 5 8 12 13 20 24 26 27 31 33 34 36 37 40 41 42 45 46 > 47 48 49 > ones 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 > 1 1 1 1 1 > Shadow 0 1 1 1 1 1 1 1 0 1 1 1 1 0 1 0 1 0 1 1 > 0 1 0 1 0 > > However, when I try to perform this operation, I obtain: > Error in t(X1) %*% X1 : requires numeric matrix/vector arguments > > Can someone please tell me what I seem to be doing wrong? thanks. > > Sincerely, > Murali Kuchibhotla > > > Murali Kuchibhotla > Department of Economics > Iowa State University > Office:75,Heady > Phone:515-294-5452 > > [[alternative HTML version deleted]] > > ______________________________________________ > 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.
Hi Murali, So, the solution to your problem will be to explicitly convert your matrix to a numeric matrix. Maybe matrix (?matrix) will do, or you'll also have to use as.numeric (?as.numeric). The strings on the left seem to me to be the row labels, right..?, not elements in the matrix/table. As a newbie, the thing you probably have to get used to/read up with is the distinction between tables, which can contain any sort of data and can not always be used in matrix calculations and (numeric) matrices/vectors. Cheers, Tsjerk On Fri, Jul 18, 2008 at 3:47 AM, Murali K <murali.jnu1 at gmail.com> wrote:> Hello, > I am a newcomer to R and therefore apologize for posting such a > basic question. I am > trying to multiply 2 matrices t(X1)%*%X1, where t(X1) is: > > > 1 2 3 4 5 8 12 13 20 24 26 27 31 33 34 36 37 40 41 42 45 46 > 47 48 49 > ones 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 > 1 1 1 1 1 > Shadow 0 1 1 1 1 1 1 1 0 1 1 1 1 0 1 0 1 0 1 1 > 0 1 0 1 0 > > However, when I try to perform this operation, I obtain: > Error in t(X1) %*% X1 : requires numeric matrix/vector arguments > > Can someone please tell me what I seem to be doing wrong? thanks. > > Sincerely, > Murali Kuchibhotla > > > Murali Kuchibhotla > Department of Economics > Iowa State University > Office:75,Heady > Phone:515-294-5452 > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. >-- Tsjerk A. Wassenaar, Ph.D. Junior UD (post-doc) Biomolecular NMR, Bijvoet Center Utrecht University Padualaan 8 3584 CH Utrecht The Netherlands P: +31-30-2539931 F: +31-30-2537623