[R] plotting on an image

[Johann Kim]

Thanks Greg,

Using rasterImage and the steps you described  works fine!
I agree with the distraction! But my purpose is to superimpose a heat map of eye tracking data on the original picture...

Thanks!




----- original message --------

Subject: RE: [R] plotting on an image
Sent: Wed, 15 Jun 2011
From: Greg Snow<Greg.Snow at imail.org>

> If you are willing to prepend a step then you could:
> 
> 1. Create an empty plot using your data and type='n' (or just plot the data,
> the points will be overwritten), you may want to set the asp argument, or
> explicitly do the xlim and ylim arguments.
> 2. Add the graphic using the rasterImage function
> 3. Use functions such as points or lines (or others that add to existing
> plots) to plot you data on top of the image.
> 
> If you need certain points within the image to correspond to certain
> coordinates then the locator and updateusr (TeachingDemos package) may be of
> help.
> 
> But in all of this, make sure that you really want to do this, often (but
> not always) putting an image in the background is chartjunk that distracts
> more than helps.
> 
> -- 
> Gregory (Greg) L. Snow Ph.D.
> Statistical Data Center
> Intermountain Healthcare
> greg.snow at imail.org
> 801.408.8111
> 
> 
> > -----Original Message-----
> > From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> > project.org] On Behalf Of Johann Kim
> > Sent: Monday, June 13, 2011 12:33 PM
> > To: r-help at r-project.org
> > Subject: [R] plotting on an image
> > 
> > Hello all,
> > 
> > has someone please a few hints about how to
> > 1.st: draw an image (preferrably a jpg) and then
> > 2nd: plot() on that image
> > 
> > I am using a mac - and after searching and trying  different ways (I
> > have installed EBImage) I now would like to ask for help...
> > 
> > Thanks!
> > Johann
> > ______________________________________________
> > 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.
> 

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