[R] identify() and postscript output
In the following, I'm fitting a logistic regression model, and using car:::influencePlot. When I run the latter with output to the screen, it calls identify() that lets me label observations with large CookD. However, if I use postscript() to get .eps output, identify() seems not to be called at all. If instead, I use dev.copy2eps() after getting output to the screen, the point labels do not appear in the resulting .eps graph. Why? Is there a workaround? library(vcd) data(Arthritis) # define Better Arthritis$Better <- Arthritis$Improved > 'None' arth.mod1 <- glm(Better ~ Age + Sex + Treatment , data=Arthritis, family='binomial') library(car) # influence plot #postscript(file="arthritis-diag2.eps", paper="special", height=6, width=6, onefile=TRUE, horizontal=FALSE) influencePlot(arth.mod1, main="Arthritis data: influencePlot") #dev.off() -Michael -- Michael Friendly Email: friendly AT yorku DOT ca Professor, Psychology Dept. York University Voice: 416 736-5115 x66249 Fax: 416 736-5814 4700 Keele Streethttp://www.math.yorku.ca/SCS/friendly.html Toronto, ONT M3J 1P3 CANADA __ 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.
Re: [R] identify() and postscript output
From the help page: "Details identify is a generic function, and only the default method is described here. identify is only supported on screen devices such as X11, windows and quartz. On other devices the call will do nothing." Why not collect the specifics of the identified points and then replot to your chosen output device perhaps with a different color or a text label? identify should return a value that can be used for that purpose. The help page provides an example that should be modifiable for that purpose. -- David Winsemius On Mar 5, 2009, at 9:18 AM, Michael Friendly wrote: In the following, I'm fitting a logistic regression model, and using car:::influencePlot. When I run the latter with output to the screen, it calls identify() that lets me label observations with large CookD. However, if I use postscript() to get .eps output, identify() seems not to be called at all. If instead, I use dev.copy2eps() after getting output to the screen, the point labels do not appear in the resulting .eps graph. Why? Is there a workaround? library(vcd) data(Arthritis) # define Better Arthritis$Better <- Arthritis$Improved > 'None' arth.mod1 <- glm(Better ~ Age + Sex + Treatment , data=Arthritis, family='binomial') library(car) # influence plot #postscript(file="arthritis-diag2.eps", paper="special", height=6, width=6, onefile=TRUE, horizontal=FALSE) influencePlot(arth.mod1, main="Arthritis data: influencePlot") #dev.off() -Michael -- Michael Friendly Email: friendly AT yorku DOT ca Professor, Psychology Dept. York University Voice: 416 736-5115 x66249 Fax: 416 736-5814 4700 Keele Streethttp://www.math.yorku.ca/SCS/friendly.html Toronto, ONT M3J 1P3 CANADA __ 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.
Re: [R] identify() and postscript output
Prof Brian Ripley wrote:
If instead, I use dev.copy2eps() after getting output to the screen,
the point labels do not appear in the resulting .eps graph. Why? Is
there a workaround?
I don't think that is true:
plot(1:10)
identify(1:10)
## Click near points 6 and 7
dev.copy2eps("test.eps")
and the points I selected are marked in test.eps.
Since Michael ignored the posting guide (again) we have no idea of
what version etc of R he used: I checked on 2.8.1 on Linux and also on
Mac OS. This was once a bug, fixed a while ago.
My bad. Thanks for Ripleying me. I'm using Win XP, R 2.8.1 with packages
shown under sessionInfo() below.
> plot(1:10)
> identify(1:10)
> ## Click near points 6 and 7
> dev.copy2eps("test.eps")
Error in device(...) : unknown family 'test.eps'
I get output on WinXP by specifying file=
> dev.copy2eps(file="test.eps")
windows
2
But still no joy -- test.eps *does not* contain the point labels (I
clicked on 7 & 8). It's not a viewer problem --
I checked with gv on Linux. Perhaps that bug wasn't fixed on WinXP?
I also attach a .png screen shot of the R graphics window.
> sessionInfo()
R version 2.8.1 (2008-12-22)
i386-pc-mingw32
locale:
LC_COLLATE=English_United States.1252;LC_CTYPE=English_United
States.1252;LC_MONETARY=English_United
States.1252;LC_NUMERIC=C;LC_TIME=English_United States.1252
attached base packages:
[1] grid stats graphics grDevices utils datasets
methods base
other attached packages:
[1] gnm_0.9-8vcdExtra_0.3-4 vcd_1.2-2colorspace_1.0-0
MASS_7.2-45 nnet_7.2-45
[7] lattice_0.17-20 car_1.2-12
loaded via a namespace (and not attached):
[1] qvcalc_0.8-4 tools_2.8.1
>
--
Michael Friendly Email: friendly AT yorku DOT ca
Professor, Psychology Dept.
York University Voice: 416 736-5115 x66249 Fax: 416 736-5814
4700 Keele Streethttp://www.math.yorku.ca/SCS/friendly.html
Toronto, ONT M3J 1P3 CANADA
test.eps
Description: PostScript document
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