Thanks Barry. I have now got as far as creating the png (or gif or tiff) images (as per your suggestions). But I am unable to work out how to convert each to a 2 dimensionional numeric matrix showing the spatial distribution of occupied/unoccupied pixels in R. Any suggestions anybody? Thanks
Terry -----Original Message----- From: b.rowling...@googlemail.com [mailto:b.rowling...@googlemail.com] On Behalf Of Barry Rowlingson Sent: Thursday, 19 May 2011 4:19 PM To: Beutel, Terry S Cc: r-help@r-project.org Subject: Re: [R] Converting the graphics window to a data matrix On Thu, May 19, 2011 at 5:19 AM, Beutel, Terry S <terry.beu...@deedi.qld.gov.au> wrote: > I'm wondering if anyone is aware of a way to take what is visible in > the R graphics window, pixelate it, and express that pixellation in a > numeric matrix. For example, I am using the following command to > create a black (present) and white (absent) spatial simulation of > grass tussock distribution. > >> > symbols(x=runif(100,-.5,1.5),y=runif(100,-.5,1.5),circles=runif(100)/3 > 0, > inches=F,bg=1,xlim=c(0,1),ylim=c(0,1)) > > What I would like to end up with is a 2 dimensional matrix that > indicates presence/absence of grass in any given pixel as per the > image generated from the above graphics plot. Instead of drawing to the screen, you can use the 'png' function to create a graphics device that "draws" to an image file. Then you can read that image file into R and get it as a matrix. You probably also want to set some of the margin and axis parameters so the plotting region fills the whole device, and you dont have the axes and tick marks etc confusing the matrix. That's some pointers for starters. I've not had breakfast yet... Barry ********************************DISCLAIMER**************************** The information contained in the above e-mail message or messages (which includes any attachments) is confidential and may be legally privileged. It is intended only for the use of the person or entity to which it is addressed. If you are not the addressee any form of disclosure, copying, modification, distribution or any action taken or omitted in reliance on the information is unauthorised. Opinions contained in the message(s) do not necessarily reflect the opinions of the Queensland Government and its authorities. If you received this communication in error, please notify the sender immediately and delete it from your computer system network. ______________________________________________ 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.
