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From | "Martin Weiss" <martin.weiss1@gmx.de> |
To | <statalist@hsphsun2.harvard.edu> |
Subject | st: AW: RE: AW: RE: RE: RE: RE: RE: RE: RE: AW: xtline, xtline2 and cmissing(n) |
Date | Mon, 17 May 2010 16:10:46 +0200 |
<> " There is no point in overlaying graphs when a single graph can be drawn." Would you be able to tell from the dialog box that a -varlist- can be passed to -line-? I could not. The dropdown seems to be able to handle -varname-s exclusively... HTH Martin -----Ursprüngliche Nachricht----- Von: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] Im Auftrag von Nick Cox Gesendet: Montag, 17. Mai 2010 16:03 An: statalist@hsphsun2.harvard.edu Betreff: st: RE: AW: RE: RE: RE: RE: RE: RE: RE: AW: xtline, xtline2 and cmissing(n) Not quite. My allusion was to <http://www.hsph.harvard.edu/cgi-bin/lwgate/STATALIST/archives/statalist .1005/date/article-766.html> which offered the recipe separate response, by(panelid) veryshortlabel local vars `r(varlist)' twoway connected `vars' time, cmissing(n ..) A modification of your example is clear set obs 4 gen id=_n expand 10 bys id: gen time=_n gen x=runiform() xtset id time replace x=. if runiform()<.3 separate x, by(id) veryshortlabel local vars `r(varlist)' tw connected `vars' time, cmissing(n ..) more tw line `vars' time, cmissing(n ..) What are the differences? 1. The option -veryshortlabel- with -separate- is better for graph purposes. This was "documented" within SJ-5-4 gr0023 . . . . Stata tip 27: Classifying data points on scatter plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N. J. Cox Q4/05 SJ 5(4):604--606 (no commands) tips for using separate, gray-scale gradation, and text characters as class symbols to classify data points on a scatter plot 2. There is no point in overlaying graphs when a single graph can be drawn. 3. -twoway connected- has the advantage over -twoway line- that isolated data points are shown clearly. Nick n.j.cox@durham.ac.uk Martin Weiss So, Giovanni, Nick`s proposal could be implemented (I imagine) as: ************* clear* vers 10.1 set obs 4 gen id=_n expand 10 bys id: gen time=_n gen x=runiform() xtset id time replace x=. if runiform()<.3 separate x, by(id) local opts cmissing(n) tw (line x1 time,`opts') (line x2 time,`opts') /* */ (line x3 time,`opts') (line x4 time,`opts') ************* -recast()-ing to -line- as I did in one of my earlier posts was of course asinine, as the thing already was a -line- graph by default. Nick Cox Martin has a solution here. But -xtline*- have rationale largely as convenience wrappers. Having to type that specification once for every panel is a bit awkward. (I do know that a wrapper programming that -- a metawrapper? -- is possible.) Using -separate- before a direct call to -twoway line- still looks a competitor. Nick n.j.cox@durham.ac.uk Martin Weiss Last word on this issue from my side: I showed earlier how the -overlay- variant of -xtline- requires -plot#opts()- specifications, which do accept the -cmissing()- option. This seems to work just fine in 10.1. -help xtline- does not promise to accept your syntax. -overlay()- only honours -overlaid_options-... *********** clear* vers 10.1 set obs 4 gen id=_n expand 10 bys id: gen time=_n gen x=runiform() xtset id time replace x=. if runiform()<.3 local opts cmissing(n) xtline2 x, overlay plot1opts(`opts') plot2opts(`opts') /* */ plot3opts(`opts') plot4opts(`opts') *********** Giovanni Vecchi Martin to make ma point clear, I'll build on your example: ************** clear vers 11 set obs 4 gen id=_n expand 10 bys id: gen time=_n gen x=runiform() xtset id time replace x=. if runiform()<.3 xtline x, overlay cmissing(n) name(mygr, replace) ************** the last line returns an error message. the two options -cmissing(n)- and -overlay- do not seem to get along. -xtline2- suffers from the same problem. Following up on the above example: ************** version 10.1 xtline2 x, overlay cmissing(n) name(mygr, replace) ************** returns the same error message. My conclusion is that there is a problem with -xtline- in need of consideration. Personally, I also do not like to be forced to switch between -xtline- and -xtline2-, depending on the Stata version I am (or my co-author is) using. * * 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/