Jim, Perfect Many thanks once more for your support... Best regards SV Envoyé de mon iPhone
Le 7 mai 2015 à 00:01, Jim Lemon <drjimle...@gmail.com> a écrit : > Hi Sacha, > As Brian noted, you will have to expand the vertical axis. Here is one > way to do it. > > plot(GDP.per.head, fitted(LinearModel.1),ylim=c(-60,1200)) > devlm1<-lm(fitted(LinearModel.1)~GDP.per.head) > abline(devlm1) > conflm1<-confint(devlm1) > abline(coef=conflm1[,1],lty=2) > abline(coef=conflm1[,2],lty=2) > predict(LinearModel.1, interval = "prediction") > library(plotrix) > predmat<-predict(LinearModel.1, interval = "prediction") > dispersion(GDP.per.head,fitted(LinearModel.1), > predmat[,3],predmat[,2],interval=FALSE) > > You may want to do something about the overlapping points. > > Jim > > > On Thu, May 7, 2015 at 5:52 AM, David L Carlson <dcarl...@tamu.edu> wrote: >> Something like this? >> >> # Compute the prediction limits and get their range to set ylim= >> plim <- predict(LinearModel.1, interval = "prediction") >> rnge <- c(min(plim[ , 2]), max(plim[ , 3])) >> plot(GDP.per.head, fitted(LinearModel.1),ylim=rnge) >> >> # As before >> devlm1<-lm(fitted(LinearModel.1)~GDP.per.head) >> abline(devlm1) >> conflm1<-confint(devlm1) >> abline(coef=conflm1[,1],lty=2) >> abline(coef=conflm1[,2],lty=2) >> >> # Plot the prediction limits >> segments(GDP.per.head, plim[ , 2], GDP.per.head, plim[ , 3], col="gray") >> >> ------------------------------------- >> David L Carlson >> Department of Anthropology >> Texas A&M University >> College Station, TX 77840-4352 >> >> >> -----Original Message----- >> From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of Cade, Brian >> Sent: Wednesday, May 6, 2015 2:22 PM >> To: varin sacha >> Cc: R-help Mailing List >> Subject: Re: [R] Drawing the regression line and the 95% confidence intervals >> >> The prediction intervals are likely to be much wider than the confidence >> intervals so you will need to be sure you scale the yaxis limits large >> enough to see them. >> >> Brian >> >> Brian S. Cade, PhD >> >> U. S. Geological Survey >> Fort Collins Science Center >> 2150 Centre Ave., Bldg. C >> Fort Collins, CO 80526-8818 >> >> email: ca...@usgs.gov <brian_c...@usgs.gov> >> tel: 970 226-9326 >> >> >> On Wed, May 6, 2015 at 12:59 PM, varin sacha <varinsa...@yahoo.fr> wrote: >> >>> Dear Jim, >>> >>> I really thank you lots, it perfectly works ! >>> The reproducible example is below. >>> >>> Last thing : I can easily get the predictions intervals but I don't get to >>> draw them. >>> If I want to draw on the same graph (the one I already have the confidence >>> intervals) the prediction intervals. I have tried the abline function >>> without success. How can I do ? >>> >>> GDP.per.head=c(600,560,340,560,580,300,570,900,680,290,590,340) >>> Quality.score=c(4.5,6.5,6,4.5,7,3,9,10,12.5,6.5,7,9) >>> Competitivness.score=c(1000,1200,1400,700,680,1010,340,560,690,500,690,460) >>> LinearModel.1=lm(GDP.per.head ~ Quality.score + Competitivness.score) >>> >>> plot(GDP.per.head, fitted(LinearModel.1),ylim=c(200,800)) >>> devlm1<-lm(fitted(LinearModel.1)~GDP.per.head) >>> abline(devlm1) >>> conflm1<-confint(devlm1) >>> abline(coef=conflm1[,1],lty=2) >>> abline(coef=conflm1[,2],lty=2) >>> predict(LinearModel.1, interval = "prediction") >>> >>> Many thanks once more for your help. >>> Sacha >>> >>> >>> ----- Mail original ----- >>> De : Jim Lemon <drjimle...@gmail.com> >>> À : varin sacha <varinsa...@yahoo.fr> >>> Cc : R-help Mailing List <r-help@r-project.org> >>> Envoyé le : Mercredi 6 mai 2015 1h02 >>> Objet : Re: [R] Drawing the regression line and the 95% confidence >>> intervals >>> >>> Hi Sacha, >>> The line you have requested is off the plot. The following will >>> produce what I think you are asking, but I cannot speak for whether it >>> means anything sensible. >>> >>> plot(GDP.per.head, fitted(LinearModel.1),ylim=c(200,800)) >>> devlm1<-lm(fitted(LinearModel.1)~GDP.per.head) >>> abline(devlm1) >>> conflm1<-confint(devlm1) >>> abline(coef=conflm1[,1],lty=2) >>> abline(coef=conflm1[,2],lty=2) >>> >>> Jim >>> >>> >>> >>> On Wed, May 6, 2015 at 8:01 AM, varin sacha <varinsa...@yahoo.fr> wrote: >>>> Hi, Dear R-helpers, >>>> >>>> Here below you will find a reproducible fictitious example working >>> except the "abline" function. >>>> >>>> First thing : I try to draw the regression line (multiple linear >>> regression). I try the "abline" function but it does not work. I don't get >>> any error message but the straight line does not appear on the scatterplot. >>>> >>>> Second thing : I try to draw the 95% confidence intervals on the >>> regression line. How could I do ? >>>> >>>> Using abline(0,1), I can of course add a line 45 degrees angle passing >>> through the origin (intercept=0 and slope=1), but it is not what I am >>> looking for. >>>> >>>> GDP.per.head=c(600,560,340,560,580,300,570,900,680,290,590,340) >>>> Quality.score=c(4.5,6.5,6,4.5,7,3,9,10,12.5,6.5,7,9) >>> Competitivness.score=c(1000,1200,1400,700,680,1010,340,560,690,500,690,460) >>>> LinearModel.1=lm(GDP.per.head ~ Quality.score + Competitivness.score) >>>> plot(GDP.per.head, fitted(LinearModel.1)) >>>> abline(GDP.per.head, fitted(LinearModel.1)) >>>> >>>> Thanks for your help. Looking forward to reading you. >>>> >>>> Sacha >>>> >>>> ______________________________________________ >>>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >>>> 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 -- To UNSUBSCRIBE and more, see >>> 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. >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >> 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 -- To UNSUBSCRIBE and more, see >> 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 -- To UNSUBSCRIBE and more, see 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.
