Roy, Yes, t(y-X %*% b) is the transpose of y-X %*% b. In principle the product of t(y-X %*% b) *(y-X %*% b) is a scalar, I don't know why I have an error message after the following line:
(t(y-X %*% b)%*%(y-X %*% b)/(length(y)-ncol(X)))*solve(t(X)%*% X) Thanks On Sat, May 21, 2016 at 9:10 PM, Roy Mendelssohn - NOAA Federal < roy.mendelss...@noaa.gov> wrote: > > str(t(y-X %*% b)) > num [1, 1:10] 0.595 -1.7538 -0.0498 -1.651 -0.6328 ... > > str((y-X %*% b)) > num [1:10, 1] 0.595 -1.7538 -0.0498 -1.651 -0.6328 … > > -Roy > > > > On May 21, 2016, at 12:00 PM, george brida <george.br...@gmail.com> > wrote: > > > > Dear R users: > > > > I have written the following lines : > > > >> x=c(10,11,12,13,14,17,15,16,10,11,41,25,26,14,12,14,15,20,14,22) > >> x=matrix(x,ncol=2) > >> a=matrix(1,nrow(x),1) > >> X=cbind(a,x) > >> y=c(12.00, 11.00, 13.00, 12.50, 14.00, 18.50, 15.00, 12.50, 13.75, > 15.00) > > > >> b=solve(t(X)%*% X)%*% t(X)%*% y > > > > when I wrote the following line > >> (t(y-X %*% b)%*%(y-X %*% b)/(length(y)-ncol(X)))*solve(t(X)%*% X) > > I have obtained an error message, I don't know why namely (t(y-X %*% > > b)%*%(y-X %*% b)/(length(y)-ncol(X))) is a scalar: > >> (t(y-X %*% b)%*%(y-X %*% b)/(length(y)-ncol(X))) > > [,1] > > [1,] 3.620354 > > > > > > Can you please help me. > > > > Thank you > > > > George > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > > 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. > > ********************** > "The contents of this message do not reflect any position of the U.S. > Government or NOAA." > ********************** > Roy Mendelssohn > Supervisory Operations Research Analyst > NOAA/NMFS > Environmental Research Division > Southwest Fisheries Science Center > ***Note new address and phone*** > 110 Shaffer Road > Santa Cruz, CA 95060 > Phone: (831)-420-3666 > Fax: (831) 420-3980 > e-mail: roy.mendelss...@noaa.gov www: http://www.pfeg.noaa.gov/ > > "Old age and treachery will overcome youth and skill." > "From those who have been given much, much will be expected" > "the arc of the moral universe is long, but it bends toward justice" -MLK > Jr. > > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.