Skip to content

Instantly share code, notes, and snippets.

View jsoffer's full-sized avatar

Jaime Soffer jsoffer

10 followers · 0 following
  • Israel
View GitHub Profile
@jsoffer
jsoffer / gist:802466
Created January 30, 2011 02:47
-- LFSR, en formato compatible con
-- http://homepage.mac.com/afj/taplist.html
-- uso (en ghci):
-- > let t = ciclo 7 $ drop 7 $ leer $ generar "1111111" [7,6,4,2]
-- "1111111" es cadena inicial con 7 registros
-- [7, 6, 4, 2] es cuarteta en http://homepage.mac.com/afj/7bits.txt
-- 'ciclo 7' se detiene cuando se repite la secuencia de los 7 primeros símbolos
-- > t
-- "00111110110111000000101000011011
@jsoffer
jsoffer / gist:844640
Created February 25, 2011 22:35
-- head = LSB
decimal_a_bool :: Integer -> [Bool]
decimal_a_bool 1 = [True]
decimal_a_bool n = odd n : decimal_a_bool (div n 2)
bool_a_decimal :: [Bool] -> Integer
-- La cadena vacía no tiene representación
bool_a_decimal [] = error "Sin entrada"
@jsoffer
jsoffer / gist:846151
Created February 27, 2011 12:42
porTresMasUno :: [Bool] -> [Bool]
porTresMasUno xs = False : ys ++ residuo where
cs = True : zipWith3 gc cs (tail xs) xs
gc b = if b then (||) else (&&)
ys = zipWith3 gy cs (tail xs ++ [False]) xs
gy p q r = (p /= q) /= r
residuo = if last cs then [True] else []
serie :: String -> [[Bool]]
serie s = takeWhile (not.alto) $ iterate paso $ leer s where
@jsoffer
jsoffer / gist:846667
Created February 27, 2011 23:02
-- CollatzBool.hs
module CollatzBool where
porTresMasUno :: [Bool] -> [Bool]
porTresMasUno xs = False : ys ++ residuo where
cs = True : zipWith3 gc cs (tail xs) xs
gc b = if b then (||) else (&&)
ys = zipWith3 gy cs (tail xs ++ [False]) xs
gy p q r = (p /= q) /= r
@jsoffer
jsoffer / gist:862100
Created March 9, 2011 12:17
PARI/GP
La serie formal generada por (3*x^2 + 5)/((1-x^2)*(1-x)^2) hasta x^99, el O(x^n)
representa el error y al sumarlo GP entiende que es serie en lugar de solamente
función racional
? p = (3*x^2 + 5)/((1-x^2)*(1-x)^2) + O(x^100)
Extrae el coeficiente de x^45
@jsoffer
jsoffer / gist:875648
Created March 18, 2011 05:07
Recurrencia a(n+2) + 2*a(n+1) + 2*a(n) = 0, n >= 0, a(0) = 1, a(1) = 3
[GP] (recuperando las raíces)
? polroots(x^2+2*x+2)
%1 = [-1.000000000000000000000000000 - 1.000000000000000000000000000*I, -1.000000000000000000000000000 + 1.000000000000000000000000000*I]~
[Haskell]
(construyendo la recurrencia directamente)
@jsoffer
jsoffer / gist:1284803
Created October 13, 2011 17:03
/* archivo, test.c */
#include <stdio.h>
void main () {
char c;
c = c & 0;
printf("The value of c is %d", (int)c);
int j = 255;
c = (c | j);
@jsoffer
jsoffer / gist:1672258
Created January 24, 2012 20:07
paradoja del cumpleaños, para 3 personas
import Math.Combinat.Numbers
import Data.Ratio
-- OEIS A141765: el número de cadenas de longitud n en un alfabeto de
-- longitud r que no repiten más de dos veces el mismo símbolo
t :: Integer -> Integer -> Integer
t r n = sum $ map g [a..r] where
a = quot (n+1) 2
g k = if n < k then 0 else
@jsoffer
jsoffer / gist:1993795
Created March 7, 2012 15:27
Distinguiendo memoria virtual reservada de memoria actualmente usada
/* reservando memoria, sin usarla */
#include <unistd.h>
#include <stdlib.h>
#define PAGESIZE 4096
#define SIZE 1212 * PAGESIZE
int main() {
int i;
@jsoffer
jsoffer / gist:2283881
Created April 2, 2012 14:34
'top' output
last pid: 1681; load averages: 0.02, 0.03, 0.00 up 0+01:53:18 09:35:32
25 processes: 2 running, 22 sleeping, 1 waiting
CPU: 2.3% user, 0.0% nice, 1.5% system, 0.0% interrupt, 96.2% idle
Mem: 84M Active, 50M Inact, 32M Wired, 4K Cache, 34M Buf, 77M Free
Swap: 512M Total, 2668K Used, 509M Free
PID USERNAME THR PRI NICE SIZE RES STATE TIME WCPU COMMAND
1102 jaime 6 20 0 134M 98792K uwait 3:20 0.00% /home/jaime/OperaDownloads/opera-dir/lib/opera/opera -pd /hom
820 jaime 1 20 0 69752K 58080K select 0:45 0.10% X -nolisten tcp (Xorg)
808 jaime 1 20 0 16376K 7732K select 0:02 0.00% urxvtd -q