Re: [R] Matrix multiplications

Thank you very much Peter. On Sat, May 21, 2016 at 9:18 PM, peter dalgaard wrote: > > > On 21 May 2016, at 21:00 , george brida wrote: > > > > Dear R users: > > > > I have written the following lines : > > > >>

Re: [R] Matrix multiplications

I don't know if there is some sort of propagation delay, but the reason has already been given and multiple fixes suggested. -pd > On 21 May 2016, at 21:26 , george brida wrote: > > Roy, > > Yes, t(y-X %*% b) is the transpose of y-X %*% b. In principle the product >

Re: [R] Matrix multiplications

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

Re: [R] Matrix multiplications

> On 21 May 2016, at 21:00 , george brida 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,

Re: [R] Matrix multiplications

> 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 wrote: > > Dear R users: > > I have written the following lines : >

[R] Matrix multiplications

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