On Sun, Feb 01, 2004 at 01:53:14PM -0500, Charles Annis, P.E. wrote: > Greetings Friends: > > I am trying to find a widget or some other method to let me interrogate a > 2-D image using the mouse. I have a data.frame that I can visualize using > image() in R. I would like to point to a pixel and have its coordinates > displayed. > > I've read Peter Dalgaard's primer on R-Tcl/Tk, R-News, 1(3):27-31, and his > update R-News2(3):25-27, but am still struggling. > > Can anyone suggest a method for interactively interrogating of a 2-D image?
Look at the InteractiveTkrPlot example on James Wettenhall's site: http://bioinf.wehi.edu.au/~wettenhall/RTclTkExamples/InteractiveTkrPlot.html His example is over discrete set of points, which you can adapt to find the location with respect to curves or lines (which I did at work, where I can't get to right now). The key is that the 'widget' you bind to an event (like left-Mouse in his example) get (x,y) pixel coordinates from the system which given appropriate information from par() can be translated into your data coordinates in just a few steps. James' site is a treasure chest for R and tcltk. Highly recommended. Hope this helps, Dirk -- The relationship between the computed price and reality is as yet unknown. -- From the pac(8) manual page ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
