bet@ecsvax.UUCP (Bennett E. Todd III) (09/14/85)
I just posted a package of three programs to net.sources for generating
and displaying the Mandelbrot set. They are written in DeSmet C, and
generate displays on the IBM Color Graphics Adaptor for the IBM PC and
the IBM Personal Computer Color Printer. Aside from two assembler
routines setup_scr() and putpoint() in the Color Graphics Adaptor
display program (ibmcg4.c) they should be reasonable portable, and
hopefully not too difficult to modify for whatever graphics device you
favor.
--
"Hypocrisy is the vaseline of social intercourse." (Who said that?)
Bennett Todd -- Duke Computation Center, Durham, NC 27706-7756; (919) 684-3695
UUCP: ...{decvax,seismo,philabs,ihnp4,akgua}!mcnc!ecsvax!duccpc!betsean@ukma.UUCP (Sean Casey) (09/16/85)
Could you post some good sample values for input?
Sean
--
- Sean Casey UUCP: sean@ukma.UUCP or
- Department of Mathematics {cbosgd,anlams,hasmed}!ukma!sean
- University of Kentucky ARPA: ukma!sean@ANL-MCS.ARPAbet@ecsvax.UUCP (Bennett E. Todd III) (09/17/85)
In article <2197@ukma.UUCP> sean@ukma.UUCP (Sean Casey) writes: >Could you post some good sample values for input? Sorry 'bout that -- an obvious omission. Here are the headers from the files I have generated so far: Centered at -0.240000+0.000000i, scale 1.757800+1.528500i, 320x200 Centered at -0.720000+0.250000i, scale 0.019531+0.016984i, 320x200 Centered at -0.915000+0.270000i, scale 0.019531+0.016984i, 320x200 Centered at -1.410000+0.000000i, scale 0.019531+0.016984i, 320x200 Centered at -0.160000+1.030000i, scale 0.019531+0.016984i, 320x200 Centered at -0.550000+0.640000i, scale 0.019531+0.016984i, 320x200 Centered at -0.760000+0.110000i, scale 0.019531+0.016984i, 320x200 Centered at -0.240000+0.000000i, scale 1.757800+1.171866i, 1008x336 Centered at -0.760000+0.110000i, scale 0.025476+0.016984i, 1008x336 Centered at -0.720000+0.250000i, scale 0.025476+0.016984i, 1008x336 Centered at -0.915000+0.270000i, scale 0.025476+0.016984i, 1008x336 Centered at -1.410000+0.000000i, scale 0.025476+0.016984i, 1008x336 Centered at -0.160000+1.030000i, scale 0.025476+0.016984i, 1008x336 Centered at -0.550000+0.640000i, scale 0.025476+0.016984i, 1008x336 The 320x200 frames go nicely on the Color Graphics Adaptor; the 1008x336 come out about 4x6" on the Color Printer. The former take a few hours; the latter take more (one that I timed took 14 hours). This is with DeSmet C using the 8087 library; not optimal floating point performance by any means. Also, it looks to me like the zoomed in pictures on the Color Printer (90x zoom if I recall the numbers correctly) show pretty bad graininess around the border of the set. Either the double-precision 8087 support is slightly bad, or 255 isn't enough iterations. I fear the latter. Again, sorry about the omission. And to explain about the input parameters again, the command compute name center=a+bi scale=c+di hpix=e vpix=f creates a data file a little over hpix*vpix bytes long, for the picture centered at a+bi, going from a-c to a+c in the real direction and b-d to b+d in the imaginary, hpix pixels horizontally by vpix vertically. To cut down on typing I added a "like=name" option, so after computing one of the pictures you can get the scale, hpix, and vpix from it and just specify a new center by compute newname center=a+bi like=oldname As you can see, I should have put more effort into the algorithm and less into the user interface:-). Anybody have any concrete info on how many iterations are required to properly resolve the set at a given zoom? -Bennett -- "Hypocrisy is the vaseline of social intercourse." (Who said that?) Bennett Todd -- Duke Computation Center, Durham, NC 27706-7756; (919) 684-3695 UUCP: ...{decvax,seismo,philabs,ihnp4,akgua}!mcnc!ecsvax!duccpc!bet