Dear liang.che, I'm guessing that this is the qqPlot() function in the car package.
This looks to me to be the combination of two problems: (1) You have at least one observation in your model for which the leverage (hat-value) is 1. That could happen, for example, if you have a factor in the model with only one observation at a particular level. (2) qqPlot() isn't handling that degenerate situation properly. Not only did I have to guess that you're using qqPlot() in the car package, but I had to guess what the problem is. If you read the text from r-help at the bottom of your message, you'll see that it says, "provide commented, minimal, self-contained, reproducible code." If you'd like help beyond my remarks above, you're more likely to get it if you provide the commands and data for your problem. Of course, we'll take a look at qqPlot() to see whether it's doing something unreasonable, and fix it if we find a problem. Best, John ----------------------------------------------- John Fox Senator McMaster Professor of Social Statistics Department of Sociology McMaster University Hamilton, Ontario, Canada > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] > On Behalf Of liang....@us.pwc.com > Sent: Sunday, November 04, 2012 1:31 PM > To: r-help@r-project.org > Subject: [R] 95% Q-Q Plot error message > > Can someone please help with the error message below? > > Warning messages: > 1: Not plotting observations with leverage one: > 7 > 2: Not plotting observations with leverage one: > 7 > > print(qqPlot(fit),envelop=.95); > Error in model.frame.default(formula = Y ~ X - 1, drop.unused.levels = > TRUE) : > variable lengths differ (found for 'X') > In addition: Warning message: > In matrix(yhat, n, reps) : > data length [9] is not a sub-multiple or multiple of the number of rows > [8] > > Thanks! > > ______________________________________________________________________ > The information transmitted, including any attachments, is intended only > for the person or entity to which it is addressed and may contain > confidential and/or privileged material. Any review, retransmission, > dissemination or other use of, or taking of any action in reliance upon, > this information by persons or entities other than the intended > recipient is prohibited, and all liability arising therefrom is > disclaimed. If you received this in error, please contact the sender and > delete the material from any computer. PricewaterhouseCoopers LLP is a > Delaware limited liability partnership. This communication may come > from PricewaterhouseCoopers LLP or one of its subsidiaries. > > [[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. ______________________________________________ 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.
