More threads (or filaments). A re-sampled gif is scheduled for tomorrow. If you want you can avoid the risk of generating the par then saying I want my 15 minutes back by visiting the usual http://maxitersfractalfollies.blogspot.com for the completed version. fract313.gif { ; threads ; blank ; calctime 0:15:18.14 ; created Jul 16, 2010 ; Fractint Version 2004 Patchlevel 9 reset=2004 type=formula formulafile=kerrym.frm formulaname=starnear_jul center-mag=-0.497582/0.874017/7.559265 params=0.375/0.375/0.5/2/2/35 float=y maxiter=1500 inside=0 decomp=256 periodicity=0 colors=05F05F05F16G16G16G16G16G27H27H27H27H27H38I38I38I38I38I49J49J49J49\ J49J5AK5AK5AK5AK5AK6BL6BL6BL6BL7CM7CM7CM7CM7CM8DN8DN8DN8DN8DN9EO9EO9EO9E\ O9EOAFPAFPAFPAFPAFPBGQBGQBGQBGQBGQCHRCHRCHRCHRCHRDISDISDISDISDISEISEJTFJ\ TFKTGKUGLUHLVHMVIMVINWJNWJOWKOXKPXLPYLQYMQYMRZNRZNSZOS_OT_PT_PT`QU`QUaRV\ aRVaSWbSWbTXbTXcUYcUYcVZdVZdW_eW_eX`eX`fYafYafZbgZbg_ch_ch`ch`diadiaeibe\ jbfjcfjcgkdgkdhlehleilfimfjmgjmgknhknhlniloimojmpjmpknpknqloqloqmprmprnq\ snqsorsortpstpstqtuqturuuruvsvvsvwtwwtwwuxxuxxuxxvyyvyywzzvyyvyyuxxtxxtw\ wsvwsvvruvquuqtupstostorsnqsnqrmprlpqloqknpjnpjmoimohlnhkngkmgjmfjleileh\ kdhkcgjcfjbfibeiaeh`dh`cg_cgZbfZbfYaeX`eX`dW_dW_cVZcUYbUYbTXaSWaSW`RV`RV\ _QU_PTZPTZOSYNSYNRXMQXLQWLPWKPVKOVJNUINUIMTHLTGLSGKSFKRFJREIQDIQDHPCHPBG\ OBFOAFN9EN9EM8DM8CL7CL6BK6AK5AJ49J49I38I37H27H16G16G05F } frm:starnear_jul { ; Kerry Mitchell 09oct98 ; ; Julia set, colors by nearest approach to 5 point star ; p1 = Julia parameter ; p2 = center of star ; cabs(real(p3)) = star size of star (try 1) ; sign(real(p3)) = pixel flag: ; + = don't consider pixel--start after first iteration ; - = consider pixel ; imag(p3) = star rotation angle, degrees ; only use angles from 0 to 36 degrees ; use decomp=256, bailout hardcoded to 10^12 ; ; initialize iteration parameters ; c=p1, zc=pixel, done=0, iter=1 bailout=1e12, fmin=bailout ; ; star parameters ; center=p2, xcen=real(center), ycen=imag(center) r=cabs(real(p3)), pixelflag=0 if(real(p3)<0) pixelflag=1 endif phi=imag(p3)/180*pi, twopi=2*pi, temp=twopi/10 t0=phi, t1=t0+temp t2=t1+temp, t3=t2+temp, t4=t3+temp, t5=t4+temp t6=t5+temp, t7=t6+temp, t8=t7+temp, t9=t8+temp ; ; set up control points ; x0=r*cos(t0)+xcen, y0=r*sin(t0)+ycen x1=r*cos(t2)+xcen, y1=r*sin(t2)+ycen x2=r*cos(t4)+xcen, y2=r*sin(t4)+ycen x3=r*cos(t6)+xcen, y3=r*sin(t6)+ycen x4=r*cos(t8)+xcen, y4=r*sin(t8)+ycen ; ; if pixel flag =/= 0, then check pixel for how close ; it is to star ; if(pixelflag!=0) x=real(zc), y=imag(zc), t=imag(log(zc-center)) if(t<0) t=t+twopi endif if((t>t0)&&(t<=t1)) f=x*(y0-y2)+y*(x2-x0)-x2*y0+x0*y2 elseif((t>t1)&&(t<=t2)) f=x*(y1-y4)+y*(x4-x1)-x4*y1+x1*y4 elseif((t>t2)&&(t<=t3)) f=x*(y1-y3)+y*(x3-x1)-x3*y1+x1*y3 elseif((t>t3)&&(t<=t4)) f=x*(y2-y0)+y*(x0-x2)-x0*y2+x2*y0 elseif((t>t4)&&(t<=t5)) f=x*(y2-y4)+y*(x4-x2)-x4*y2+x2*y4 elseif((t>t5)&&(t<=t6)) f=x*(y3-y1)+y*(x1-x3)-x1*y3+x3*y1 elseif((t>t6)&&(t<=t7)) f=x*(y3-y0)+y*(x0-x3)-x0*y3+x3*y0 elseif((t>t7)&&(t<=t8)) f=x*(y4-y2)+y*(x2-x4)-x2*y4+x4*y2 elseif((t>t8)&&(t<=t9)) f=x*(y4-y1)+y*(x1-x4)-x1*y4+x4*y1 else f=x*(y3-y0)+y*(x0-x3)-x0*y3+x3*y0 endif fmin=cabs(f) endif : ; standard iteration, find polar angle of iterate ; iter=iter+1, zc=sqr(zc)+c x=real(zc), y=imag(zc), t=imag(log(zc-center)) if(t<0) t=t+twopi endif ; ; compute how close iterate is to each side of star ; if((t>t0)&&(t<=t1)) f=x*(y0-y2)+y*(x2-x0)-x2*y0+x0*y2 elseif((t>t1)&&(t<=t2)) f=x*(y1-y4)+y*(x4-x1)-x4*y1+x1*y4 elseif((t>t2)&&(t<=t3)) f=x*(y1-y3)+y*(x3-x1)-x3*y1+x1*y3 elseif((t>t3)&&(t<=t4)) f=x*(y2-y0)+y*(x0-x2)-x0*y2+x2*y0 elseif((t>t4)&&(t<=t5)) f=x*(y2-y4)+y*(x4-x2)-x4*y2+x2*y4 elseif((t>t5)&&(t<=t6)) f=x*(y3-y1)+y*(x1-x3)-x1*y3+x3*y1 elseif((t>t6)&&(t<=t7)) f=x*(y3-y0)+y*(x0-x3)-x0*y3+x3*y0 elseif((t>t7)&&(t<=t8)) f=x*(y4-y2)+y*(x2-x4)-x2*y4+x4*y2 elseif((t>t8)&&(t<=t9)) f=x*(y4-y1)+y*(x1-x4)-x1*y4+x4*y1 else f=x*(y3-y0)+y*(x0-x3)-x0*y3+x3*y0 endif f=cabs(f) ; ; update minimum distance ; if(f<fmin) fmin=f zmin=zc endif ; ; upon escape or maximum iterations: ; set "done" flag ; use minimum distance from star as polar angle of z ; for use with decomp coloring ; if((|zc|>bailout)||(iter==maxit)) done=1 t=log(fmin) z=cos(t)+flip(sin(t)) endif done==0 } Roger Alexander _________________________________________________________________