James writes: > Have you tried det(x) and/or eigen(x) ? > > A zero determinant (within computer precision) means that the matrix > does not have full rank, i.e. it does not span R4. Count how many > eigenvalues are zero (within computer precision). What does this > tell you?
I'm still on chapter 1 and we have not yet covered eigenvalues so this is a bit fuzzy. > > In the Solutions Manual, there is mention of the gauss() and > >bgauss() functions which apparently written by Lay - these are to > >speed up matrix reduction but I have not noticed these functions in R. > > Have you encountered speed problems in R? Do you really need these > functions in R in addition to solve(), backsolve() etc. ? If you > just want to learn about how they work you could have a look at the > Matlab code for these functions (which I think you have access to). > You could even try rewriting them in R yourself. No, the speed is fine but I'm in early Linear Algebra and am working with basic matrices right now. I do have access to the author's functions and I may try re-writing those in R - that should be a good project and should help me better understand R as I'm a novice. Thank you, Elizabeth ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
