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From |
David Airey <david.airey@vanderbilt.edu> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: RE: yscale in anovaplot |

Date |
Sun, 26 Apr 2009 13:35:34 -0500 |

. Typical plots in the context of a split plot design are here: http://www.ats.ucla.edu/stat/stata/examples/kirk/kirkstata12.htm -Dave On Apr 26, 2009, at 1:19 PM, David Airey wrote:

.In the simplest within subject design, the paired ttest, it makessense to plot the data by subject, a line per subject. Or if youmeasure subjects repeatedly over time, it also makes sense to keepthe graphic by subject. Or if you measure two groups, pre and post,it makes sense to plot either two groups of different colored lines(one line per subject) or ignore subject and make a profile plot asother software does. As far as I can tell, none of the permutationsof the factors does this, and that is why I said anovaplot is forbetween subjects designs only, or as the help says with maybe onecovariate. My query was as much to Diego, who seemed satisfied withhis use of -anovaplot- in a repeated measures context. I was justcurious what his final plot looked like and from what model.Cheers, -Dave On Apr 26, 2009, at 12:14 PM, Nick Cox wrote:You use it the way you expect to be most fruitful.I'm not minded to go upstream and find out what the example isabout, orlearn enough about the subject-matter to make a guess at whatshould bemost helpful. But the default -anovaplot- has no inbuilt intelligence. It's likelythat some permutation of the factors improves on the default plot,forexample anovaplot s a b A simple but important issue is that whenever identifiers are quite arbitrary, putting them on one axis may not yield a clear picture. It may be worth re-labelling identifiers to make structure clearer. Nick n.j.cox@durham.ac.uk David Airey I always use it for between subjects ANOVAs. Perfect for that. The key thing in my response is that _I_ have not been satisfied with my use in within subject designs or mixed models. Maybe I was not using it correctly. Let's use an example from UCLA ATS, so that I can get it as correctly intended. From http://www.ats.ucla.edu/stat/stata/faq/xtmixed.htm just focusing on the ANOVA aspects of the page, let's do: use http://www.ats.ucla.edu/stat/stata/examples/kirk/spf2-4, clear anova y a / s|a b a*b /, repeated(b) How do you use -anovaplot- here? -Dave On Apr 26, 2009, at 11:26 AM, Nick Cox wrote:2.1.1 is the latest publicly available version.-anovaplot- plots observed and fitted values after -anova- interms ofpredictor levels. It's a bit surprising to hear that you never found that useful. What do you do instead? A while back I went carefully through various classic texts on ANOVA from the 1950s. As I recall none of them included any plots based on data. Nick n.j.cox@durham.ac.uk David Airey I never found -anovaplot- useful for anything but between subject designs. I'd be curious to see the repeated measures plots using - anovaplot-. Is the version on SSC not the latest? I have . which anovaplot /Users/dairey/Library/Application Support/Stata/ado/plus/a/ anovaplot.ado *! 2.1.1 NJC 6 November 2004 -Dave On Apr 26, 2009, at 10:52 AM, Nick Cox wrote:Thanks to Diego for this interesting question and to Thomas for answering it so fully. To fill in a gap and to fill out the implicitly needed discussion:-anovaplot- is a program in the -modeldiag- package written up intheStata Journal within SJ-4-4 gr0009 . . . . . . . . . . Speaking Stata: Graphing model diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N. J. Cox (help anovaplot, indexplot, modeldiag, ofrtplot, ovfplot, qfrplot, racplot, rdplot, regplot, rhetplot, rvfplot2, rvlrplot, rvpplot2 if installed) Q4/04 SJ 4(4):449--475 plotting diagnostic information calculated from residuals and fitted values from regression models with continuous responses There's also an equivalent package on SSC that includes older versions of these programs. The paper is accessible to all via http://www.stata-journal.com/sjpdf.html?articlenum=gr0009 -anovaplot- is described on p.458. I add this comment, which is relevant to Diego's question: "It is curious that analysis-of-variance people typically draw interaction plots but suppress the data, whereas regression peopleprefer to draw scatterplots showing both observed and fittedvalues.Admittedly, a complicated set of crossing lines showinginteractionsmay seem to leave little scope for showing data effectively, while a relatively simple regression leaves plenty of scope, but the difference is nevertheless intriguing."I still treasure a comment made by a senior Stata user, who mightnotwant to be named for this, to the effect that showing the data onthegraph typically confuses the issue. Nevertheless I'll think about adding a -nodata- option, possibly with a sting in the tail. (For example, it might -drop- all your data, or some such.) Nick n.j.cox@durham.ac.uk Thomas Steichen =============== Although you have suppressed printing a symbol for the data points via -scatter(msym(none))-, Stata still allows room for that invisible datain its y-axis range. Therefore you cannot reduce the range giventheway the code is written. Editing the code to allow what you want is pretty straightforward. Change line: numlist "2/`= 1 + `: word count `fits'''" To: numlist "1/`= 1 + `: word count `fits'''" And line: twoway scatter `y' `x1' if e(sample), `scatter' /// To: twoway `scatter' /// Then edit line: program anovaplot, sort To: program anovaplot0, sort Save it with new name anovaplot0.ado and invoke it with command -anovaplot0- Nick Cox's original will keep working and you'll have this one for your purpose.Of course, you could get fancy and add a -nodata- option thatallowsboth forms in a single program. Diego Bellavia ============== I am trying to plot an ANOVA for repeated measures model using the amazing anovaplot command. Everything works fine except the yscale range. I need to reduce the range and increase the scale to make differences clear. So I tried: anovaplot level groups, scatter(msym(none)) yscale (range(-12 -24)) ylabel(-12 (2) -24) The problem is that I actually reduced the numbered range and the labelling but now almost half of the graph is empty. Is there any way to change the range so that I can take advantage of all the graph extension ?* * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/* * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

* * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**Follow-Ups**:**RE: st: RE: yscale in anovaplot***From:*"Nick Cox" <n.j.cox@durham.ac.uk>

**References**:**st: re: first difference in multidimensional panel***From:*Kit Baum <baum@bc.edu>

**st: yscale in anovaplot***From:*Diego Bellavia <bellavia.diego@mac.com>

**st: RE: yscale in anovaplot***From:*"Nick Cox" <n.j.cox@durham.ac.uk>

**Re: st: RE: yscale in anovaplot***From:*David Airey <david.airey@vanderbilt.edu>

**RE: st: RE: yscale in anovaplot***From:*"Nick Cox" <n.j.cox@durham.ac.uk>

**Re: st: RE: yscale in anovaplot***From:*David Airey <david.airey@vanderbilt.edu>

**RE: st: RE: yscale in anovaplot***From:*"Nick Cox" <n.j.cox@durham.ac.uk>

**Re: st: RE: yscale in anovaplot***From:*David Airey <david.airey@vanderbilt.edu>

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