Unfortunately, the transposition of lines and list was a typo on my part. Now that I look like a fool and have corrected the issue, I'm still faced with the same dilemma. With the original data set I posted in this thread,
plot(mpg~x, data=mileage[year==2009,], ylab="Miles per gallon", xlab="2009", yaxs="i", ylim=c(10,30)) nls.2009 <- nls(mpg~(alpha*(as.numeric(x)^2))+(bravo*as.numeric(x))+(charlie), data=mileage[year==2009,], start=list(alpha=-2e-14, bravo=5e-5, charlie=-31407), trace=T, na.action=na.omit, nls.control(minFactor=0.000000000000000000001)) plot(mpg~x, data=mileage[year==2009,]) modb=seq(min(as.numeric(x)), max(as.numeric(x)), by=10000)#; modb lines(modb, predict(nls.2009, list(as.numeric(x) = modb))) The last line returns the following error: Error: unexpected '=' in " lines(modb, predict(nls.2009, list(as.numeric(x) =" I've tried putting in modb as the "newdata" in the predict() statement, but I end up with Error in xy.coords(x, y) : 'x' and 'y' lengths differ SR Steven H. Ranney On Mon, Jul 18, 2011 at 7:52 AM, Peter Ehlers <ehl...@ucalgary.ca> wrote: > On 2011-07-18 06:38, Steven Ranney wrote: >> >> Provided, of course, that I alter the lines for different data sets >> and data frames, the code to plot a line derived from nls() onto a >> plot works with no problems. >> >> Here's an example: >> >> Year NOP >> 2002 6 >> 2003 8 >> 2004 11 >> 2005 19 >> 2006 26 >> 2007 25 >> >> mod1<- nls(NOP~alpha*exp(beta*Year), data=aic, >> start=list(alpha=1e-278, beta=0.3205), trace=T, >> nls.control(maxiter=30000, minFactor=0.000005)) >> plot(NOP~Year, data=aic, pch=19, ylab="Number of papers") >> mod1a=seq(2002, 2007, by=.0001) >> lines(mod1a, predict(mod1, list(Year = mod1a))) > > Yes, but here's what you posted as your 'last line of code': > > lines(modb, predict(nls.2009, lines(as.numeric(x)=modb))) > > Perhaps just a typo: lines -> list??? > In any case, the newdata in predict should have a variable 'Year'. > > Peter Ehlers > >> >> I've been using this code for several years not to get models from >> nls() onto plot and I've never had an issue with it until the dataset >> I referenced in my initial email. >> >> Thanks for your assistance. >> >> SR >> >> Steven H. Ranney >> >> http://www.steven-ranney.com >> http://stevenranney.blogspot.com >> >> >> On Mon, Jul 18, 2011 at 2:55 AM, Peter Ehlers<ehl...@ucalgary.ca> wrote: >>> >>> On 2011-07-17 17:37, Steven Ranney wrote: >>>> >>>> All - >>>> >>>> I'm having an issue with trying to plot a model derived from nls() >>>> onto a simple plot. I have included a sample data set and the code >>>> that I've been using. >>>> >>>> year month day date location mileage cost gallon cpg >>>> mpg x >>>> 2009 1 4 1/4/2009 BZN 124585 19.39 14.37 1.349339 >>>> 10.71677 2009-01-04 >>>> 2009 1 15 1/15/2009 BZN 124888 23.2 16.12 1.439206 >>>> 18.79653 2009-01-15 >>>> 2009 1 27 1/27/2009 BZN 125133 21.51 14.35 1.498955 >>>> 17.07317 2009-01-27 >>>> 2009 2 16 2/16/2009 BZN 125429 27.96 15.54 1.799228 >>>> 19.04762 2009-02-16 >>>> 2009 2 27 2/27/2009 BZN 125702 26.82 14.27 1.879467 >>>> 19.13104 2009-02-27 >>>> 2009 3 19 3/19/2009 BZN 125941 24.38 12.91 1.888459 >>>> 18.51278 2009-03-19 >>>> 2009 4 9 4/9/2009 BZN 126260 32.59 16.30 1.999387 >>>> 19.57055 2009-04-09 >>>> 2009 4 28 4/28/2009 BZN 126587 34.58 16.79 2.059559 >>>> 19.47588 2009-04-28 >>>> 2009 5 17 5/17/2009 BZN 126925 35.78 16.57 2.159324 >>>> 20.39831 2009-05-17 >>>> 2009 5 27 5/27/2009 BZN 127240 35.57 15.01 2.369753 >>>> 20.98601 2009-05-27 >>>> 2009 6 7 6/7/2009 BZN 127590 40.99 16.60 2.469277 >>>> 21.08434 2009-06-07 >>>> 2009 6 21 6/21/2009 BZN 127910 41.52 15.64 2.654731 >>>> 20.46036 2009-06-21 >>>> 2009 7 21 7/21/2009 BZN 128264 43.37 16.67 2.601680 >>>> 21.23575 2009-07-21 >>>> 2009 8 11 8/11/2009 BZN 128618 42.68 16.42 2.599269 >>>> 21.55907 2009-08-11 >>>> 2009 8 27 8/27/2009 BZN 128947 43.12 16.60 2.597590 >>>> 19.81928 2009-08-27 >>>> 2009 9 21 9/21/2009 BZN 129255 40.44 15.56 2.598972 >>>> 19.79434 2009-09-21 >>>> 2009 10 1 10/1/2009 BZN 129541 38.55 14.83 2.599461 >>>> 19.28523 2009-10-01 >>>> 2009 10 11 10/11/2009 BZN 129806 36.65 14.10 2.599291 >>>> 18.79433 2009-10-11 >>>> 2009 10 22 10/22/2009 BZN 130027 30.18 11.61 2.599483 >>>> 19.03531 2009-10-22 >>>> 2009 11 9 11/9/2009 BZN 130358 43.19 16.62 2.598676 >>>> 19.91576 2009-11-09 >>>> 2009 11 22 11/22/2009 BZN 130631 39.23 15.09 2.599735 >>>> 18.09145 2009-11-22 >>>> 2009 12 5 12/5/2009 BZN 130950 44.43 17.09 2.599766 >>>> 18.66589 2009-12-05 >>>> 2009 12 30 12/30/2009 BZN 131239 42.14 16.70 2.523353 >>>> 17.30539 2009-12-30 >>>> >>>> After converting my dates into R-usable dates: >>>> >>>> #convert my dates to R-usable dates >>>> x<- strptime(date, format="%m/%d/%Y") >>>> x >>>> mileage<- cbind(mileage, x) >>>> >>>> I plot the data and model mpg as a function of date. In the nls() >>>> statement, I convert x back to a numeric value so that I can conduct >>>> the regression: >>>> >>>> plot(mpg~x, data=mileage[year==2009,], ylab="Miles per gallon", >>>> xlab="2009", yaxs="i", ylim=c(10,30)) >>>> nls.2009<- >>>> nls(mpg~(alpha*(as.numeric(x)^2))+(bravo*as.numeric(x))+(charlie), >>>> data=mileage[year==2009,], start=list(alpha=-2e-14, bravo=5e-5, >>>> charlie=-31407), >>>> trace=T, na.action=na.omit, >>>> nls.control(minFactor=0.000000000000000000001)) >>>> plot(mpg~x, data=mileage[year==2009,]) >>>> modb=seq(min(as.numeric(x)), max(as.numeric(x)), by=10000) >>>> lines(modb, predict(nls.2009, lines(as.numeric(x)=modb))) >>>> >>>> Unfortunately, when I run the final line of this code, I get the >>>> following: >>>> >>>> Error: unexpected '=' in " lines(modb, predict(nls.2009, >>>> lines(as.numeric(x)=" >>>> >>>> In other similar analyses, I've been able to plot an nls() model using >>>> this exact code--altered of course according to information--but here >>>> I'm at a loss. I'm certain it has something to do with the >>>> lines(...as.numeric(x)) value I'm trying to plot, but I can't figure >>>> out what I'm doing wrong. >>> >>> That last line of code doesn't look right to me. The arguments >>> that you need to supply to predict() are 'object' and 'newdata', >>> where 'newdata' must have the appropriate form. Unless you have >>> your own function lines(), I don't think that lines(as.numeric(x)=modb) >>> would qualify as newdata. >>> >>> It's usually a bad idea to shove too much stuff into a single command >>> and a good idea to use str() often. >>> >>> This 'exact' code worked in the past? >>> >>> Peter Ehlers >>> >>>> >>>> The model is fine, but it's the plotting of the model that escapes me. >>>> >>>> I'm running R version 2.12.1 on a Windows 7 machine. >>>> >>>> Thanks for your help - >>>> >>>> Steven H. Ranney >>>> >>>> http://stevenranney.blogspost.com >>>> http://www.steven-ranney.com >>>> >>>> ______________________________________________ >>>> 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. >>> >>> > > ______________________________________________ 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.
