Hi, I want to test for independence in my GLS model fitp2, but when I try to use the dwtest function in the lmtest library, I get the error message "Error in terms.default(formula) : no terms component". The model and data set are below. Any suggestions would be really helpful! Thanks a lot in advance, M. Grace fitp2: fitp2<-gls(V3_total~D_total+P_total,data=pdata,weights=varPower()) based on the data set pdata: pdata D_total V3_total P_total 1 75 158000 302.033 2 221 258000 126.664 3 1050 280000 538.547 4 8100 208000 1090.068 5 22100 235000 2038.937 6 5300 570000 2626.226 7 3250 454000 2326.473 8 6540 169000 5613.525 9 5248 247000 6011.532 10 22484 542000 15140.006 11 30841 530000 13324.048 12 7480 497000 10481.812 13 2664 467000 5776.274 14 432 285000 1849.763 ------------------------------------------------------------------ University of St Andrews Webmail: https://webmail.st-andrews.ac.uk
The help file for dwtest says formula: a symbolic description for the model to be tested (or a fitted "lm" object). It is not clear from your message, but it would seem that you used fitp2 as the argument to dwtest. (In any case, this gives the error message you quote?) But fitp2 is neither a formula, nor is it an object ineriting from "lm". Why did you expect dwtest to work on a gls object? Bill Venables CSIRO Laboratories PO Box 120, Cleveland, 4163 AUSTRALIA Office Phone (email preferred): +61 7 3826 7251 Fax (if absolutely necessary): +61 7 3826 7304 Mobile: +61 4 8819 4402 Home Phone: +61 7 3286 7700 mailto:Bill.Venables at csiro.au http://www.cmis.csiro.au/bill.venables/ -----Original Message----- From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of mm745 at st-andrews.ac.uk Sent: Sunday, 27 July 2008 6:26 AM To: r-help at r-project.org Subject: [R] GLS "no terms component" error Hi, I want to test for independence in my GLS model fitp2, but when I try to use the dwtest function in the lmtest library, I get the error message "Error in terms.default(formula) : no terms component". The model and data set are below. Any suggestions would be really helpful! Thanks a lot in advance, M. Grace fitp2: fitp2<-gls(V3_total~D_total+P_total,data=pdata,weights=varPower()) based on the data set pdata: pdata D_total V3_total P_total 1 75 158000 302.033 2 221 258000 126.664 3 1050 280000 538.547 4 8100 208000 1090.068 5 22100 235000 2038.937 6 5300 570000 2626.226 7 3250 454000 2326.473 8 6540 169000 5613.525 9 5248 247000 6011.532 10 22484 542000 15140.006 11 30841 530000 13324.048 12 7480 497000 10481.812 13 2664 467000 5776.274 14 432 285000 1849.763 ------------------------------------------------------------------ University of St Andrews Webmail: https://webmail.st-andrews.ac.uk ______________________________________________ R-help at 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.
Thank you, Bill. I think I misread some text in my statistics handbook. This has helped to clear it up. Sorry for taking up your time and thank you for replying. M. Grace Quoting Bill.Venables at csiro.au:> The help file for dwtest says > > formula: a symbolic description for the model to be tested (or a fitted > "lm" object). > > It is not clear from your message, but it would seem that you used fitp2 > as the argument to dwtest. (In any case, this gives the error message > you quote?) > > But fitp2 is neither a formula, nor is it an object ineriting from "lm". > > Why did you expect dwtest to work on a gls object? > > > Bill Venables > CSIRO Laboratories > PO Box 120, Cleveland, 4163 > AUSTRALIA > Office Phone (email preferred): +61 7 3826 7251 > Fax (if absolutely necessary): +61 7 3826 7304 > Mobile: +61 4 8819 4402 > Home Phone: +61 7 3286 7700 > mailto:Bill.Venables at csiro.au > http://www.cmis.csiro.au/bill.venables/ > > -----Original Message----- > From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] > On Behalf Of mm745 at st-andrews.ac.uk > Sent: Sunday, 27 July 2008 6:26 AM > To: r-help at r-project.org > Subject: [R] GLS "no terms component" error > > Hi, > > I want to test for independence in my GLS model fitp2, but when I try to > use the > dwtest function in the lmtest library, I get the error message "Error in > terms.default(formula) : no terms component". > > The model and data set are below. Any suggestions would be really > helpful! > Thanks a lot in advance, > > M. Grace > > > fitp2: > fitp2<-gls(V3_total~D_total+P_total,data=pdata,weights=varPower()) > > based on the data set pdata: > pdata > D_total V3_total P_total > 1 75 158000 302.033 > 2 221 258000 126.664 > 3 1050 280000 538.547 > 4 8100 208000 1090.068 > 5 22100 235000 2038.937 > 6 5300 570000 2626.226 > 7 3250 454000 2326.473 > 8 6540 169000 5613.525 > 9 5248 247000 6011.532 > 10 22484 542000 15140.006 > 11 30841 530000 13324.048 > 12 7480 497000 10481.812 > 13 2664 467000 5776.274 > 14 432 285000 1849.763 > > > ------------------------------------------------------------------ > University of St Andrews Webmail: https://webmail.st-andrews.ac.uk > > ______________________________________________ > R-help at 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. > > >------------------------------------------------------------------ University of St Andrews Webmail: https://webmail.st-andrews.ac.uk