Re: Strange size changes in Manipulate with GeometricTransformation

*To*: mathgroup at smc.vnet.net*Subject*: [mg92210] Re: [mg92156] Strange size changes in Manipulate with GeometricTransformation*From*: John Fultz <jfultz at wolfram.com>*Date*: Tue, 23 Sep 2008 07:31:36 -0400 (EDT)*Reply-to*: jfultz at wolfram.com

This bug had already been discovered by our QA department and logged in our database. I've added a pointer to your post to that bug report. In the mean time, the way to work around this is to provide an explicit PlotRange. E.g., Manipulate[ Graphics[ GeometricTransformation[ { EdgeForm[Black], FaceForm[], Disk[{0, 0}, 1, {\[Pi], 2 \[Pi]}], Disk[{0, 0}, 1, {0, \[Pi]}] }, RotationTransform[x] ], PlotRange->{{-1.1,1.1},{-1.1,1.1}} ], {x, -180, 180} ] Also note that x is in radians, not degrees, which is why your example rotates so very quickly. Sincerely, John Fultz jfultz at wolfram.com User Interface Group Wolfram Research, Inc. On Mon, 22 Sep 2008 05:24:39 -0400 (EDT), Nazdrovje wrote: > > > Hi group, > > I was playing with Manipulate and GeometricTransformation and found a > strange difference in behaviour when manipulating the orientation of a > circle containing a line depending on how it was drawn. Below, I > provide two ways of drawing this configuration. The first one behaves > as expected, but moving the slider in the second example results in > unexpected size changes. > > I suppose it must have something to do with bounding boxes of the > building blocks, but I don't quite get it. I also feel the behaviour > of the second one is actually wrong. What do you folks think? > > Cheers -- Nazdrovje > > This one rotates as expected: > > Manipulate[ > Graphics[ > GeometricTransformation[ > { > Circle[], > Line[{{-1, 0}, {1, 0}}] > }, RotationTransform[x] > ] > ], {x, -180, 180} > ] > > This one behaves erratical: > > Manipulate[ > Graphics[ > GeometricTransformation[ > { > EdgeForm[Black], > FaceForm[], > Disk[{0, 0}, 1, {\[Pi], 2 \[Pi]}], > Disk[{0, 0}, 1, {0, \[Pi]}] > }, RotationTransform[x] > ] > ], {x, -180, 180} > ]