Do you know that there are NaN's in the output of bs(raw_data[,i],df=15)? any(is.nan(bs(raw_data[,i],df=15))) would tell you. Do you know that there are fewer than c. 18 distinct values in raw_data[,i]? length(unique(raw_data[,i])) would tell you. If there are not very many distinct values then use fewer degrees of freedom in bs().
Bill Dunlap Spotfire, TIBCO Software wdunlap tibco.com From: jgrn...@gmail.com [mailto:jgrn...@gmail.com] On Behalf Of Jonathan Greenberg Sent: Thursday, April 18, 2013 6:50 AM To: William Dunlap Subject: Re: [R] Singular design matrix in rq William: Thanks! Given that I'm just trying to "drape a sheet" on top of the data, can you recommend a better "smoother" to use? --j On Tue, Apr 16, 2013 at 4:40 PM, William Dunlap <wdun...@tibco.com<mailto:wdun...@tibco.com>> wrote: Have you looked at the result of bs(raw_data[,i], df=15) ? If there are not many unique values in the input there will be a lot of NaN's in the output (because there are repeated knots) and those NaN's will cause rq() to give that message. E.g., > d <- data.frame(y=sin(1:100), x4=rep(1:4,each=25), x50=rep(1:50,each=2)) > rq(data=d, y ~ bs(x4, df=15), tau=.8) # using x50 "works" Error in rq.fit.br<http://rq.fit.br>(x, y, tau = tau, ...) : Singular design matrix > with(d, bs(x4, df=15)) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 [1,] 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 [2,] 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 [3,] 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 ... [98,] 0 0 0 0 0 0 0 0 0 0 0 NaN NaN NaN NaN [99,] 0 0 0 0 0 0 0 0 0 0 0 NaN NaN NaN NaN [100,] 0 0 0 0 0 0 0 0 0 0 0 NaN NaN NaN NaN attr(,"degree") [1] 3 attr(,"knots") 7.692308% 15.38462% 23.07692% 30.76923% 38.46154% 1 1 1 2 2 46.15385% 53.84615% 61.53846% 69.23077% 76.92308% 2 3 3 3 4 84.61538% 92.30769% 4 4 attr(,"Boundary.knots") [1] 1 4 attr(,"intercept") [1] FALSE attr(,"class") [1] "bs" "basis" "matrix" Bill Dunlap Spotfire, TIBCO Software wdunlap tibco.com<http://tibco.com> > -----Original Message----- > From: r-help-boun...@r-project.org<mailto:r-help-boun...@r-project.org> > [mailto:r-help-boun...@r-project.org<mailto:r-help-boun...@r-project.org>] On > Behalf > Of Jonathan Greenberg > Sent: Tuesday, April 16, 2013 12:58 PM > To: r-help; Roger Koenker > Subject: [R] Singular design matrix in rq > > Quantreggers: > > I'm trying to run rq() on a dataset I posted at: > https://docs.google.com/file/d/0B8Kij67bij_ASUpfcmJ4LTFEUUk/edit?usp=sharing > (it's a 1500kb csv file named "singular.csv") and am getting the following > error: > > mydata <- read.csv("singular.csv") > fit_spl <- rq(raw_data[,1] ~ bs(raw_data[,i],df=15),tau=1) > > Error in rq.fit.br<http://rq.fit.br>(x, y, tau = tau, ...) : Singular > > design matrix > > Any ideas what might be causing this or, more importantly, suggestions for > how to solve this? I'm just trying to fit a smoothed hull to the top of > the data cloud (hence the large df). > > Thanks! > > --jonathan > > > -- > Jonathan A. Greenberg, PhD > Assistant Professor > Global Environmental Analysis and Remote Sensing (GEARS) Laboratory > Department of Geography and Geographic Information Science > University of Illinois at Urbana-Champaign > 607 South Mathews Avenue, MC 150 > Urbana, IL 61801 > Phone: 217-300-1924<tel:217-300-1924> > http://www.geog.illinois.edu/~jgrn/ > AIM: jgrn307, MSN: jgrn...@hotmail.com<mailto:jgrn...@hotmail.com>, Gchat: > jgrn307, Skype: jgrn3007 > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org<mailto: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. -- Jonathan A. Greenberg, PhD Assistant Professor Global Environmental Analysis and Remote Sensing (GEARS) Laboratory Department of Geography and Geographic Information Science University of Illinois at Urbana-Champaign 607 South Mathews Avenue, MC 150 Urbana, IL 61801 Phone: 217-300-1924 http://www.geog.illinois.edu/~jgrn/ AIM: jgrn307, MSN: jgrn...@hotmail.com<mailto:jgrn...@hotmail.com>, Gchat: jgrn307, Skype: jgrn3007 [[alternative HTML version deleted]] ______________________________________________ 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.
