from the google mathmap group a new version of the kaleidoscope filter, with option to offset the center

filter newkaleido (image in, int ng: 2-20, float rot: 0-6.28319, float sx:
0-1, float sy: 0-1, float rad: 0-100)
intang=2*pi/ng;
na=a+pi/2;
ang=intang/2-na%intang;
ang=rot+(intang/2-sqrt(ang^2));
xr=r*rad;
foo=min(X,Y);
bar=foo*rad;
if xr<bar then
nr=xr;
else
ang=2*ang;
nr=bar*xr/R;
end;
nx=nr*cos(ang);
ny=nr*sin(ang);
nx=(nx+sx)%(W-1)-(X-1);
ny=(ny+sy)%(H-1)-(Y-1);
in(xy:[nx,ny])
end

NOTE
i believe the author modify the old Kaleidoscope script but not the filter name
So i changed the filter name in the first line of the code to avoid conflict
(in case you want have both version)
to add to mathmap simply save as "new kaleidoscope.mm" (or any name you wish the point is the.mm extension) in your mathmap expression folder ( i suggest there the "map" subfolder )

you may also do this directly from mathmap , first open the expression tab, clear, paste the code and click the "save as"button
I just got it , didn't test yet

It has no t variable for the animation. It works as a Kaleidoscope filter, but no animation.

I have the animation working.

Here is my mod:

filter newkaleido (image in, int ng: 2-20, float rot: 0-6.28319, float sx:
0-1, float sy: 0-1, float rad: 0-100)
intang=2*pi/ng;
na=a+pi/2;
ang=intang/2-na%intang;
ang=(rot+(intang/2-sqrt(ang^2)))*(t+1);
xr=r*rad;
foo=min(X,Y);
bar=foo*rad;
if xr<bar then
nr=xr;
else
ang=2*ang;
nr=bar*xr/R;
end;
nx=nr*cos(ang);
ny=nr*sin(ang);
nx=(nx+sx)%(W-1)-(X-1);
ny=(ny+sy)%(H-1)-(Y-1);
in(xy:[nx,ny])
end

WOW!! that was fast ...Thank PhotoMaster!

Here's a better example. I did it with more frames and slightly different settings.

I haven't been able to do much with this old machine, but this was easy for it.