This
ClearAll[DashedCircle]
DashedCircle[rs:{ri_,ro_},n_Integer,\[Theta]_:0]:=Annulus[{0,0},rs,#+\[Theta]]&/@Partition[Subdivide[0,2\[Pi],2n],2]
L={0.1,100,40};
M=20;
\[Lambda]=PowerRange[#1,#2,(#2/#1)^(1/#3)]&@@L;
\[Lambda]=Partition[\[Lambda],2,1];
Graphics[MapThread[DashedCircle[#1,M,#2 \[Pi]/M]&,{\[Lambda],Mod[Range[Length[\[Lambda]]],2,0]}]]
result in lots of "Subdivide is not a Graphics primitive or directive"-errors here...
Regarding my first post
SquareLattice[t_] :=
Graphics[{Table[
Rectangle[{i + t, j + t}], {i, -2, 42, 2}, {j, -2, 42, 2}],
Table[Rectangle[{i + 1 + t, j + 1 + t}], {i, -2, 42, 2}, {j, -2,
42, 2}]}, PlotRange -> {{0, 40}, {0, 40}}, ImageSize -> 500]
f[x_, y_] := {Log[Sqrt[(x)^2 + (y)^2]], ArcTan[x, y]}
ListAnimate[
Table[ImageTransformation[SquareLattice[t], f[#[[1]], #[[2]]] &,
DataRange -> {{-Pi, Pi}, {-Pi, Pi}}], {t, 0, .9, .1}]]
and
Why does that line exist?
Look at the Plot of ArcTan[x, y], which defines how the y coordinate
is obtained:
Plot3D[ArcTan[x, y], {x, -Pi, Pi}, {y, -Pi, Pi}]
There is a
discontinuity where that line exists in your image. I imagine it has
some numerical difficultly there.
I found out, that
Plot3D[ArcTan[x, y], {x, -Pi, Pi}, {y, -Pi, Pi}]
seems not to be part of the correct code.
What I've not found is a solution...the ready animation included in the .CDF-file available there (Link) seems to be fine - but if I evaluate it in Mathematica by myself, I'll get that line......