Re: Image Rotation
- To: mathgroup at smc.vnet.net
- Subject: [mg39335] Re: Image Rotation
- From: "Allan Hayes" <hay at haystack.demon.co.uk>
- Date: Tue, 11 Feb 2003 04:47:20 -0500 (EST)
- References: <b27fv5$nj3$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
"Ann Fitchard" <mathfit2000 at yahoo.com> wrote in message news:b27fv5$nj3$1 at smc.vnet.net... > Mathgroup, > > I have an image in the form of nested lists. I would like to rotate this image. In the standard package, I can rotate it 90 degrees at a time. I would like to rotate the image by non-specific intervals. Does anyone know how I can do this with the standard package. > > Thank you for your time. Ann, << "Geometry`Rotations`" gr = Show[Graphics[{Hue[0], Polygon[{{0, 0}, {1, 0}, {1, 1}}], Hue[2/3], Thickness[0.02], Line[{{0, 0}, {0, 1}}], PointSize[0.06], Point[{0, 0.5}]}], AspectRatio -> Automatic] grrot = gr /. p:{_?(AtomQ[#1] && Element[#1,Reals] & ), _?(AtomQ[#1] && Element[#1,Reals] & )} :> Rotate2D[p, Pi/4., {1, 1}]; Show[grrot, Frame -> True, PlotRange -> All] 1) The rotations of the objects are clockwise. 2) AtomQ is used because for example MatchQ[{{{{2, 3}, 5, 6}}}, x_ /; Element[x ,Reals]] True It seems that MatchQ[expr, x_ /; Element[x ,Reals]] is true if it is a nested list or single atom and all atoms of expr are real ( with head, Real, Rational or Integer) and no subpart of expr contains two lists. -- Allan --------------------- Allan Hayes Mathematica Training and Consulting Leicester UK hay at haystack.demon.co.uk Voice: +44 (0)116 271 4198 Fax: +44 (0)870 164 0565