On Nov 19, 2013, at 5:53 AM, Tonio wrote:
Thank you for your post. I believe that it is possible to make a function to rotate a graphical component that might be based on the rotation matrix. I'll take a look to the packages anyway...
It's certainly possible to "rotate" abstract segment endpoints using a rotation matrix. What is not possible is to claenly erase the original image and replace it with the new image. You could also repeatedly draw new plots with a segment being rotated (around what center you do not say) in angular increments and then assemble a sequence of plots with the animation package. (A rotation matrix would transform segment end-points around the origin.) As always, a complete description of the desired result is needed and I do not believe you have yet provided such.
David. > > Den 15:38 mandag den 18. november 2013 skrev David Winsemius <dwinsemius at comcast.net>: > > > On Nov 18, 2013, at 7:27 AM, Tonio wrote: > >> >> >> Dear list, >> >> Consider these two parallel segments in a plot. >> >> plot(c(1, 6), c(2, 2), type="n", xlim=c(0, 7), ylim=c(-2, 6)) >> segments(1, 1, 6, 1) >> segments(1, 3, 6, 3) >> >> >> >> How can I rotate the two lines together by a defined angle? > > Base graphics do not support object operations. You need to do the > calculation and redraw the plot. > > Either lattice or ggplot2 which depend upon the "grid" system would > have the possibility to "rotate" a component. > > -- > > David Winsemius, MD > Alameda, CA, USA David Winsemius Alameda, CA, USA