I suppose the solution is unstable because x is ill-conditioned: > x [,1] [,2] [,3] [,4] [1,] 0.133 0.254 -0.214 0.116 [2,] 0.254 0.623 -0.674 0.139 [3,] -0.214 -0.674 0.910 0.011 [4,] 0.116 0.139 0.011 0.180 > cor(x) [,1] [,2] [,3] [,4] [1,] 1.0000000 0.9963557 -0.9883690 0.8548065 [2,] 0.9963557 1.0000000 -0.9976663 0.8084090 [3,] -0.9883690 -0.9976663 1.0000000 -0.7663847 [4,] 0.8548065 0.8084090 -0.7663847 1.0000000
> kappa(x) [1] 2813.326 hth, Kingsford Jones On Thu, Jan 29, 2009 at 7:00 PM, Joseph P Gray <jpg...@uwm.edu> wrote: > I submit the following matrix to both MATLAB and R > > x= 0.133 0.254 -0.214 0.116 > 0.254 0.623 -0.674 0.139 > -0.214 -0.674 0.910 0.011 > 0.116 0.139 0.011 0.180 > > MATLAB's inv(x) provides the following > 137.21 -50.68 -4.70 -46.42 > -120.71 27.28 -8.94 62.19 > -58.15 6.93 -7.89 36.94 > 8.35 11.17 10.42 -14.82 > > R's solve(x) provides: > 261.94 116.22 150.92 -267.78 > 116.22 344.30 286.68 -358.30 > 150.92 286.68 252.96 -334.09 > -267.78 =358.30 -334.09 475.22 > > inv(x)*x = I(4) > and solve(x)%*%x = I(4) > > Is there a way to obtain the MATLAB result in R? > > Thanks for any help. > > > Pat Gray > > ______________________________________________ > R-help@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. > ______________________________________________ R-help@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.