That's correct. The option is not there. You can force it in a starting model - but it can still be deleted,
At some stage Insightful implemented a commercial set of polynomial spline functions in S-Plus that does have that option. They got it as far as a beta-library [quoting from my own homepage http://bear.fhcrc.org/~clk]: ============================ Doug Clarkson at Insightful Corp. has implemented commercial versions of hare, heft, logspline and a variety of related methods, with lots of additional features and options. See http://www.insightful.com/downloads/libraries/default.asp. Look for S+BEST. ============================ There are remaining bugs in this code.... Doug Clarkson is no longer at Insightful, and the code seems to be pretty much abbandoned. Charles Quoting Xiaogang Su <[EMAIL PROTECTED]>: > Dear Dr. Graves, > > Thanks for your information and kindness! I really appreciate it. > According to my findings so far, POLYCLASS doesnot seem to allow for > variables being forced into the model. Even the commercialized MARS > doesnot have this function either. However, one ad hoc approach that > they suggested is to fit linear (or logistic) model and form rediduals > first and then run MARS with the residuals. > > Best regards, > -XG Su > > > ================================ > Xiaogang Su, Assistant Professor > Department of Statistics and Actuarial Science > University of Central Florida > Orlando, FL 32816 > (407) 823-2940 [O] > [EMAIL PROTECTED] > http://pegasus.cc.ucf.edu/~xsu/ > > > >>> Spencer Graves <[EMAIL PROTECTED]> 7/7/2006 5:49:05 AM >>> > I have not seen a reply, so I will offer a few suggestions, > even > though I've never used the 'polspline' package. I scanned several of > the help pages and looked in "~\library\polspline' where R is installed > > on my hard drive and found no further documentation, and I found > nothing > new from RSiteSearch("polyclass"). Googling for 'polyclass' led me to > > "http://bear.fhcrc.org/~clk/soft.html", the home page for Charles > Kooperberg, the author and maintainer. If it were my problem, I might > > try writing him directly at the email address given in > help(package="polyclass"); I'm including him as a "cc" on this reply. > > I spent time looking at this, because 'polyclass', 'polymars' > and > 'polspline' seem potentially related related to one of my secondary > interests. Unfortunately, I couldn't find sufficient documentation to > > allow me to proceed with the time I felt I could afford to invest in > this right now. > > If it were my problem, before I wrote another email about > this, I'd > first list the function 'polyclass', make a local copy, then work > through an example line by line using 'debug(polyclass)'. This 'debug' > > facility is remarkably powerful and easy to use. I've solved many > problems like this using 'debug' in this way. > > If that failed to provide the necessary enlightenment, I'd > submit > another post including a self-contained example based on a modification > > of the 'iris' example featured in the 'polyclass' help page. Your > example is NOT self contained, so I would NOT use that. Using the > 'iris' example would make it much easier to explain clearly what you > want. It also makes it much easier for someone like me to experiment > with alternatives and describe what I did in terms of a tested > example. > > Hope this helps. > p.s. I suggest you also review the posting guide! > "www.R-project.org/posting-guide.html". > > Xiaogang Su wrote: > > Dear all, > > > > I have a question on how to set up the starting model in POLYCLASS > and > > make sure the terms in the starting model retained in the final > > POLYCLASS model. > > > > In the function POLYMARS, this can be done using the STARTMODEL > option. > > See below for example, I started with model > > y= b0 + b1*X1 + b2*X2 + b3*X4 + b4*X5 + b5*X2*X5 + e > > > >> m00 <- matrix(c( > > 1, NA, 0, NA, 1, > > 2, NA, 0, NA, 1, > > 4, NA, 0, NA, 1, > > 5, NA, 0, NA, 1, > > 2, NA, 5, NA, 1),nrow = 5, ncol=5, byrow=TRUE); > > > >> m2 <- polymars(response=PID2$y, predictors=PID2[,1:7], > > startmodel=m00) > >> summary(m2) > > > > But I could not figure out how this works for POLYCLASS. There is an > > option FIT in POLYCLASS, which needs to be a POLYCLASS object though. > > > > > Any suggestion or information is greatly appreciated. > > > > Sincerely, > > Xiaogang Su > > > > > > ================================ > > Xiaogang Su, Assistant Professor > > Department of Statistics and Actuarial Science > > University of Central Florida > > Orlando, FL 32816 > > (407) 823-2940 [O] > > [EMAIL PROTECTED] > > http://pegasus.cc.ucf.edu/~xsu/ > > > > ______________________________________________ > > R-help@stat.math.ethz.ch mailing list > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html > ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html