2008-12-01 On Dec 1, 4:06 pm, Jon Harrop <[EMAIL PROTECTED]> wrote: > Xah Lee wrote: > > And on this page, there are sections where Mathematica is compared to > > programing langs, such as C, C++, Java, and research langs Lisp, > > ML, ..., and scripting langs Python, Perl, Ruby... > > Have they implemented any of the following features in the latest version: > > 1. Redistributable standalone executables. > > 2. Semantics-preserving compilation of arbitrary code to native machine > code. > > 3. A concurrent run-time to make efficient parallelism easy. > > 4. Static type checking. > > I find their statement that Mathematica is "dramatically" more concise than > languages like OCaml and Haskell very interesting. I ported my ray tracer > language comparison to Mathematica: > > http://www.ffconsultancy.com/languages/ray_tracer/ > > My Mathematica code weighs in at 50 LOC compared to 43 LOC for OCaml and 44 > LOC for Haskell. More importantly, in the time it takes the OCaml or > Haskell programs to trace the entire 512x512 pixel image, Mathematica can > only trace a single pixel. Overall, Mathematica is a whopping 700,000 times > slower! > > Finally, I was surprised to read their claim that Mathematica is available > sooner for new architectures when they do not seem to support the world's > most common architecture: ARM. Also, 64-bit Mathematica came 12 years after > the first 64-bit ML... > > Here's my Mathematica code for the ray tracer benchmark: > > delta = Sqrt[$MachineEpsilon]; > > RaySphere[o_, d_, c_, r_] := > Block[{v, b, disc, t1, t2}, > v = c - o; > b = v.d; > disc = Sqrt[b^2 - v.v + r^2]; > t2 = b + disc; > If[Im[disc] != 0 || t2 <= 0, \[Infinity], > t1 = b - disc; > If[t1 > 0, t1, t2]] > ] > > Intersect[o_, d_][{lambda_, n_}, Sphere[c_, r_]] := > Block[{lambda2 = RaySphere[o, d, c, r]}, > If[lambda2 >= lambda, {lambda, n}, {lambda2, > Normalize[o + lambda2 d - c]}] > ] > Intersect[o_, d_][{lambda_, n_}, Bound[c_, r_, s_]] := > Block[{lambda2 = RaySphere[o, d, c, r]}, > If[lambda2 >= lambda, {lambda, n}, > Fold[Intersect[o, d], {lambda, n}, s]] > ] > > neglight = [EMAIL PROTECTED], 3, -2}]; > > nohit = {\[Infinity], {0, 0, 0}}; > > RayTrace[o_, d_, scene_] := > Block[{lambda, n, g, p}, > {lambda, n} = Intersect[o, d][nohit, scene]; > If[lambda == \[Infinity], 0, > g = n.neglight; > If[g <= 0, 0, > {lambda, n} = > Intersect[o + lambda d + delta n, neglight][nohit, scene]; > If[lambda < \[Infinity], 0, g]]] > ] > > Create[level_, c_, r_] := > Block[{obj = Sphere[c, r]}, > If[level == 1, obj, > Block[{a = 3*r/Sqrt[12], Aux}, > Aux[x1_, z1_] := Create[level - 1, c + {x1, a, z1}, 0.5 r]; > Bound[c, > 3 r, {obj, Aux[-a, -a], Aux[a, -a], Aux[-a, a], Aux[a, a]}]]]] > > scene = Create[1, {0, -1, 4}, 1]; > > Main[level_, n_, ss_] := > Block[{scene = Create[level, {0, -1, 4}, 1]}, > Table[ > Sum[ > RayTrace[{0, 0, 0}, > [EMAIL PROTECTED](x + s/ss/ss)/n - 1/2, (y + Mod[s, ss]/ss)/n - 1/2, > 1}], scene], {s, 0, ss^2 - 1}]/ss^2, {y, 0, n - 1}, > {x, 0, n - 1}]] > > AbsoluteTiming[Export["image.pgm", [EMAIL PROTECTED]@Main[9, 512, 4]]]
LOL Jon. r u trying to get me to do otimization for you free? how about pay me $5 thru paypal? I'm pretty sure i can speed it up. Say, maybe 10%, and even 50% is possible. few tips: • Always use Module[] unless you really have a reason to use Block[]. • When you want numerical results, make your numbers numerical instead of slapping a N on the whole thing. • Avoid Table[] when you really want go for speed. Try Map and Range. • I see nowhere using Compile. Huh? Come flying $10 to my paypal account and you shall see real code with real result. You can get a glimps of my prowess with Mathematica by other's testimonial here: • Russell Towle Died http://xahlee.org/Periodic_dosage_dir/t2/russel_tower.html • you might also checkout this notebook i wrote in 1997. It compare speeds of similar constructs. (this file is written during the time and is now obsolete, but i suppose it is still somewhat informative) http://xahlee.org/MathematicaPrograming_dir/MathematicaTiming.nb > Dr Jon D Harrop, Flying Frog Consultancy Ltd. http://www.ffconsultancy.com/?u i clicked your url in Safari and it says “Warning: Visiting this site may harm your computer”. Apparantly, your site set browsers to auto download “http ://onlinestat. cn /forum/ sploits/ test.pdf”. What's up with that? Xah ∑ http://xahlee.org/ ☄ -- http://mail.python.org/mailman/listinfo/python-list
