On 10 Apr., 16:41, "Ondrej Certik" <[EMAIL PROTECTED]> wrote: > [...] > That looks extremely interesting! It's just a simple .so file, that we > call from python, it quickly compiles everything in memory and > provides a compiled function (in memory), that you call using ctypes, > am I right? > > I like this technology. > > Ondrej
Yeah, I'm now using libtcc via ctypes interface to compile to machine code directly in memory. It works on Windows too, I only failed so far to get math.h working. Compile time is not an issue anymore (according to http://fabrice.bellard.free.fr/tcc/ it is able to compile the Linux kernel in just 10 s on a 2.4 GHz CPU). A remaining issue is the Python<->Overhead. Evaluating simple functions in a Python loop is currently faster using pure Python. This motivated me to implement evaluating functions on a range of numbers using dynamically generated machine code. I'm using pointers, this means that Python and C are using the same memory, so theres no interface overhead (except of passing the pointer one time). The result: Running tests... cexpr: 1/(g(x)*3.5)**(x - a**x)/(x**2 + a) 1/ pow((g(x)*3.5), (x - pow(a, x) )) /( pow(x, 2) + a) compiling x**(1/2)*y**(1/2)... f(0.5, 4) = 1.414214 Running benchmark... big function: compile time (including sympy overhead): 0.428471 s for x = (0, 1, 2, ..., 999)/1000 20 times in 3 runs compiled: 0.1288 0.1321 0.1334 Python lambda: 0.3407 0.3383 0.3380 Psyco lambda: 0.1547 0.1567 0.1561 simple function: compile time (including sympy overhead): 0.012746 s for x = (0, 1, 2, ..., 999)/1000 20 times in 3 runs compiled: 0.0760 0.0775 0.0786 Python lambda: 0.0526 0.0527 0.0576 Psyco lambda: 0.0662 0.0661 0.0657 frange with f(x) = x**2 * sqrt(x) for x=1, ..., 1000000 in 3 runs including full compile time frange: 0.2470 0.2186 0.2135 numpy: 0.2256 0.2162 0.2415 For big functions frange is probably faster than numpy. I'm planning to implement evaluating on arrays too. Any thoughts? Vinzent --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to sympy@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sympy?hl=en -~----------~----~----~----~------~----~------~--~---
