Thanks. So with kid.weights I will have (see below) - or is my example use of quantreg wrong? """ #growth_chart_create.R library(UsingR) library(quantreg) lbs_to_kg<-1/2.2046 inch_to_cm<-2.54 data(kid.weights) data_kids<-kid.weights data_kids$weight_kg<-kid.weights$weight*lbs_to_kg data_kids$length_cm<-kid.weights$height*inch_to_cm
colnames(data_kids)<-c('AGEMOS','WEIGHT_OLD','HEIGHT_OLD','SEX','WEIGHT','HEIGHT') Dat<-NULL Dat_temp <- subset(data_kids,SEX=='F') Dat$x <- Dat_temp$WEIGHT Dat$y <- Dat_temp$AGEMOS antal<-length(data_kids$AGEMOS) plot(Dat,xlab='Age (months)',ylab='Weight (kg)') # fit first a nonlinear least-square regression Dat.nls <- nls(y ~ SSlogis(x, Asym, mid, scal), data=Dat); #Dat.nls lines(1:antal, predict(Dat.nls, newdata=list(x=1:antal)), col=1) # then fit the median using nlrq Dat.nlrq <- nlrq(y ~ SSlogis(x, Asym, mid, scal), data=Dat, tau=0.5, trace=TRUE) lines(1:antal, predict(Dat.nlrq, newdata=list(x=1:antal)), col=2) # the 1st and 3rd quartiles regressions Dat.nlrq <- nlrq(y ~ SSlogis(x, Asym, mid, scal), data=Dat, tau=0.25, trace=TRUE) lines(1:antal, predict(Dat.nlrq, newdata=list(x=1:antal)), col=3) Dat.nlrq <- nlrq(y ~ SSlogis(x, Asym, mid, scal), data=Dat, tau=0.75, trace=TRUE) lines(1:antal, predict(Dat.nlrq, newdata=list(x=1:antal)), col=3) # and finally "external envelopes" holding 95 percent of the data Dat.nlrq <- nlrq(y ~ SSlogis(x, Asym, mid, scal), data=Dat, tau=0.025, trace=TRUE) lines(1:antal, predict(Dat.nlrq, newdata=list(x=1:antal)), col=4) Dat.nlrq <- nlrq(y ~ SSlogis(x, Asym, mid, scal), data=Dat, tau=0.975, trace=TRUE) lines(1:antal, predict(Dat.nlrq, newdata=list(x=1:antal)), col=4) leg <- c("least squares","median (0.5)","quartiles (0.25/0.75)",".95 band (0.025/0.975)") legend(30, 60, legend=leg, lty=1, col=1:4) """ On Thu, 8 Nov 2007 10:44:56 -0600, roger koenker wrote > The lmsqreg package is by Vince Carey and is available from his > website. There is an independent package with fortran routines from > Tim Cole. Both packages implement the LMS method of Cole and Green. > You might also want to consider alternative methods: an approach > based on nonparametric quantile regression is described in: > > http://www.ncbi.nlm.nih.gov/sites/entrez? > cmd=Retrieve&db=PubMed&list_uids=16143984&dopt=AbstractPlus > > Some comparison with the LMS method are reported there. > > url: www.econ.uiuc.edu/~roger Roger Koenker > email [EMAIL PROTECTED] Department of Economics > vox: 217-333-4558 University of Illinois > fax: 217-244-6678 Champaign, IL 61820 > > On Nov 8, 2007, at 10:16 AM, Niels Steen Krogh wrote: > > > We are constructing growth charts (age/weight and age/length) for > > children > > with diagnosis that impacts weight/length. > > > > But we we don't know how to use R for producing growth charts. > > > > We are collection data of Age, Weight and Length. > > The data are used to produce diagnosis-specific Growth charts (like > > the CDC > > Growth Charts: > > http://www.cdc.gov/nchs/data/nhanes/growthcharts/set1clinical/ > > cj41l017.pdf) > > > > Data-example is in the UsingR package as data(kid.weights). > > > > In the CDC-papers a LMS approch is described. Cole has programmed the > > methology (I guess) in a <R 2.0.0 package called lmsqreg: > > """ > >> library(lmsqreg) > > Error in library(lmsqreg) : > > lmsqreg' is not a valid package -- installed < 2.0.0?) > > """ > > > > Where to go forward in R. > > Thanks for any "hints". > > We are using R2.6.0 on win/linux > > > > /Niels > > > > > > > > Niels Steen Krogh > > Konsulent > > ZiteLab ApS > > > > Mail: ---------- [EMAIL PROTECTED] > > Telefon: ------- +45 38 88 86 13 > > Mobil: --------- +45 22 67 37 38 > > Adresse: ------- ZiteLab ApS > > ---------------- Solsortvej 44 > > ---------------- dk - 2000 F. > > --- og --- > > ---------------- ZiteLab ApS > > ---------------- Refshalevej 110a > > ---------------- dk - 1432 københavn k > > > > Web: ----------- www.zitelab.dk > > CVR: ----------- 29178364 > > Bank: ---------- Sparbank Vest > > > > Ejer: ---------- ZSRK Group Holding > > > > ______________________________________________ > > 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. Niels Steen Krogh Konsulent ZiteLab ApS Mail: ---------- [EMAIL PROTECTED] Telefon: ------- +45 38 88 86 13 Mobil: --------- +45 22 67 37 38 Adresse: ------- ZiteLab ApS ---------------- Solsortvej 44 ---------------- dk - 2000 F. --- og --- ---------------- ZiteLab ApS ---------------- Refshalevej 110a ---------------- dk - 1432 københavn k Web: ----------- www.zitelab.dk CVR: ----------- 29178364 Bank: ---------- Sparbank Vest Ejer: ---------- ZSRK Group Holding On Thu, 8 Nov 2007 10:44:56 -0600, roger koenker wrote > The lmsqreg package is by Vince Carey and is available from his > website. There is an independent package with fortran routines from > Tim Cole. Both packages implement the LMS method of Cole and Green. > You might also want to consider alternative methods: an approach > based on nonparametric quantile regression is described in: > > http://www.ncbi.nlm.nih.gov/sites/entrez? > cmd=Retrieve&db=PubMed&list_uids=16143984&dopt=AbstractPlus > > Some comparison with the LMS method are reported there. > > url: www.econ.uiuc.edu/~roger Roger Koenker > email [EMAIL PROTECTED] Department of Economics > vox: 217-333-4558 University of Illinois > fax: 217-244-6678 Champaign, IL 61820 > > On Nov 8, 2007, at 10:16 AM, Niels Steen Krogh wrote: > > > We are constructing growth charts (age/weight and age/length) for > > children > > with diagnosis that impacts weight/length. > > > > But we we don't know how to use R for producing growth charts. > > > > We are collection data of Age, Weight and Length. > > The data are used to produce diagnosis-specific Growth charts (like > > the CDC > > Growth Charts: > > http://www.cdc.gov/nchs/data/nhanes/growthcharts/set1clinical/ > > cj41l017.pdf) > > > > Data-example is in the UsingR package as data(kid.weights). > > > > In the CDC-papers a LMS approch is described. Cole has programmed the > > methology (I guess) in a <R 2.0.0 package called lmsqreg: > > """ > >> library(lmsqreg) > > Error in library(lmsqreg) : > > lmsqreg' is not a valid package -- installed < 2.0.0?) > > """ > > > > Where to go forward in R. > > Thanks for any "hints". > > We are using R2.6.0 on win/linux > > > > /Niels > > > > > > > > Niels Steen Krogh > > Konsulent > > ZiteLab ApS > > > > Mail: ---------- [EMAIL PROTECTED] > > Telefon: ------- +45 38 88 86 13 > > Mobil: --------- +45 22 67 37 38 > > Adresse: ------- ZiteLab ApS > > ---------------- Solsortvej 44 > > ---------------- dk - 2000 F. > > --- og --- > > ---------------- ZiteLab ApS > > ---------------- Refshalevej 110a > > ---------------- dk - 1432 københavn k > > > > Web: ----------- www.zitelab.dk > > CVR: ----------- 29178364 > > Bank: ---------- Sparbank Vest > > > > Ejer: ---------- ZSRK Group Holding > > > > ______________________________________________ > > 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. Niels Steen Krogh Konsulent ZiteLab ApS Mail: ---------- [EMAIL PROTECTED] Telefon: ------- +45 38 88 86 13 Mobil: --------- +45 22 67 37 38 Adresse: ------- ZiteLab ApS ---------------- Solsortvej 44 ---------------- dk - 2000 F. --- og --- ---------------- ZiteLab ApS ---------------- Refshalevej 110a ---------------- dk - 1432 københavn k Web: ----------- www.zitelab.dk CVR: ----------- 29178364 Bank: ---------- Sparbank Vest Ejer: ---------- ZSRK Group Holding ______________________________________________ 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.