juliusgeo

from functools import reduce
from math import factorial, comb, ceil, log2
from decimal import getcontext, Decimal as Dec


def bernoulli(n):
    bs = [Dec(1)]
    for m in range(1, n+1):
        bs.append(1 - sum(comb(m, k)*b / (m - k + 1) for k, b in zip(range(m), bs)))
    return abs(bs[-1])

juliusgeo

20 million digits of pi in under a minute with Julia

I recently discovered a relatively obscure algorithm for calculating the digits of pi: https://en.wikipedia.org/wiki/Gauss–Legendre_algorithm. Well, at least obscure compared to Chudnovsky's. Wikipedia notes that it is "memory-intensive" but is it really? Let's compare to the MPFR pi function:

function gauss_legendre(prec)
    setprecision(BigFloat, prec, base=10)
    GC.enable(false)

juliusgeo

import sys;itls,colls,binasc,struct,time=[\
 __import__(i) for i in("itertools",\
"collections","binascii","struct","time")];\
s=sys.stdin.read();(MOFFSET,MLENGTH,\
              FILE_NAME,ZIP_NAME,
             idx)=(2047,31,"a.txt"
            , "a.zip",  0); \
           compressed=[((*\
           lo,s[idx]),idx:=\
          idx+lo[1])[0] for\

juliusgeo

/build/**
/venv*/**
/.idea/**
/repro.egg-info/**
/dist/
**/*.so

juliusgeo

Bits and Pieces: zlib compliant DEFLATE from scratch

zlib underlies most zip file decompressors, and DEFLATE is one the binary formats used to store compressed data in a bitstream. The goal of this article is to walk through how my Python DEFLATE compressor implementation works. There are many guides on the internet that describe how to implement each step of DEFLATE, but very few end up producing a bitstream that can actually be parsed by a library like zlib. This article assumes that you roughly know how each step of the DEFLATE algorithm is implemented, but are having trouble with some of the finer points that are often glossed over.

The code can be found in "deflate.py".

juliusgeo

import os
timestep=1./60
gravity=-9.81
tg=timestep*gravity
s_x,s_y=10,20
u=v=[[.0 for A in range(s_y)]for A in range(s_x)]
pr=[[.0 for A in range(s_y)]for A in range(s_x)]
st=[[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],[0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1],[0,1,1,1,1,0,.1,0,0,.1,.1,.1,.1,.1,.1,.1,0,0,0,0],[0,1,1,1,1,1,.1,.1,.1,.1,.1,.1,.1,.1,.1,0,0,0,0,0],[0,1,1,1,1,1,.1,.1,.1,.1,.1,.1,.1,.1,.1,0,0,0,0,0],[0,.1,0,1,1,1,.1,.1,.1,.1,.1,.1,.1,.1,.1,0,0,0,0,0],[0,.1,0,.1,.1,.1,.1,.1,.1,.1,.1,.1,.1,.1,0,0,0,0,0,0],[0,.1,0,.2,.1,.1,.1,0,.1,.1,.1,.1,0,0,0,0,0,0,0,0],[0,.1,0,0,.2,.1,.1,0,.1,0,0,0,0,0,0,0,0,0,0,0],[0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0]]
C=1e3/timestep
loop=[(A,B)for A in range(1,len(u)-1)for B in range(1,len(u[0])-1)]

juliusgeo

h = [
    lambda a, b, c, d: 0,
    lambda a: 0,
    lambda a, b, c, d, e, f, g, h: 0,
    lambda a, b, c, d, e, f, g, h: 0,
    lambda a, b, c, d, e, f, g, h, i, j, k: 0,
    None,
    lambda a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, x, t: 0,
 lambda a, b, c, d, e, f, g, h, i, j, k, l: 0,

juliusgeo

from multiprocessing import Process
import psutil

from time import sleep


def ascii_bomb():
    return [
        """
                  .,-:-,,.

juliusgeo

n=256;q, t, m, e, p, c, f=(range(n),16,lambda x
      ,y,       r=0:m((h:=x   <<1,h^283)[
     h&n!=      0],y>>      1,(r,r    ^x)
    [y&1])if    y else       r,lambda
   a,w= 1,p=n   -2:e(m(a,       a),(w,m
  (w,a))[p&1]   ,p>>               1)if p
 else       w,  lambda    b:         list(
map      (print,["%.2x "*t%(*b[r:r+t],)for
r in [*q][::t]])),lambda a,i: (a<<i|a>>8-i)&255
,lambda a: (a^c(a,1)^c(a,2)^c(a,3)^c(a,4))^99);

juliusgeo

import os,select,tty,sys
from time import time
from functools import partial

# Need this because Unix-esque OSes are different from Windows.
try:
    from msvcrt import getch as cf
except ImportError:
    tty.setcbreak(sys.stdin.fileno())
    cf=partial(sys.stdin.read,1)