Sorry Alan but it's not my function. I just was looking for something similar a while ago and googled to find The ost whose url I sent you will have the name of the creator.
Actually I think I ended up just using symbols for my graph. --- On Sat, 3/12/11, Allan Kamau <kamaual...@gmail.com> wrote: > From: Allan Kamau <kamaual...@gmail.com> > Subject: Re: [R] Drawing a circle on an existing graph. > To: r-help@r-project.org > Received: Saturday, March 12, 2011, 3:07 PM > On Sat, Mar 12, 2011 at 10:22 PM, > David Winsemius > <dwinsem...@comcast.net> > wrote: > > > > On Mar 12, 2011, at 10:56 AM, Allan Kamau wrote: > > > >>> --- On Sat, 3/12/11, Allan Kamau <kamaual...@gmail.com> > wrote: > >>> > >>>> From: Allan Kamau <kamaual...@gmail.com> > >>>> Subject: [R] Drawing a circle on an > existing graph. > >>>> To: r-help@r-project.org > >>>> Received: Saturday, March 12, 2011, 3:08 > AM > >>>> I would like to draw a circle on a > >>>> graph I am plotting in R and use > >>>> the current plot's coordinate system. > >>>> The most basic functionality I am looking > for is the > >>>> ability to plot a > >>>> circle on an already existing graph by > simply providing the > >>>> xy > >>>> coordinates for it's centre and the > radius. > >>>> > >>>> I am also looking for a way to obtain x,y > values of a point > >>>> (of a > >>>> circle) by specifying only the origin x,y > the angle and > >>>> radius. > >>>> > >>>> Please point me so such a library and > perhaps some simple > >>>> one line code. > >>>> > >>>> Allan. > >>>> > >> On Sat, Mar 12, 2011 at 5:28 PM, John Kane <jrkrid...@yahoo.ca> > wrote: > >>> > >>> Is this of any use? > >>> http://tolstoy.newcastle.edu.au/R/help/06/04/25821.html > >>> > >> > >> Thank you John, that is what I was looking for. > >> The code does draw a neat circle that is not > stretched. After plotting > >> the circle on an existing plot I notice that the > original plot was > >> indeed stretched somehow by approximately some > 1:1.1 ratio (I think). > >> Now I am looking for a way to enforce none > stretching in my original > >> graph. > > > > `plot.window` has an `asp` argument that is useful for > that purpose. Most > > plotting with base graphics will pass an asp=1 > argument along as part of the > > `...` arguments, > > > > -- > > > > David Winsemius, MD > > West Hartford, CT > > > > > Thank you David, asp=1 argument in my plot function brought > about 1:1 > aspect ratio to the graph and now the circle sits very > neatly within > it. All is well. > John is there another version of your circle drawing code > that accepts > values in accordance with the current plot's scale units in > place of > the current real distance measurement (inches) units. > > Allan. > > ______________________________________________ > 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.
