Code
2024-01-13 10:00:01

求π的最快方法是什么?

我正在寻找最快的方法来获得π的值，作为一个个人挑战。更具体地说，我使用的方法不涉及使用#define常量M_PI，或硬编码的数字。

下面的程序测试了我所知道的各种方法。从理论上讲，内联汇编版本是最快的选择，尽管显然不能移植。我将它作为一个基准，与其他版本进行比较。在我的测试中，使用内置函数，4 * atan(1)版本在GCC 4.2上是最快的，因为它自动将atan(1)折叠成一个常量。通过指定-fno-builtin, atan2(0， -1)版本是最快的。

下面是主要的测试程序(pitimes.c):

#include <math.h>
#include <stdio.h>
#include <time.h>

#define ITERS 10000000
#define TESTWITH(x) {                                                       \
    diff = 0.0;                                                             \
    time1 = clock();                                                        \
    for (i = 0; i < ITERS; ++i)                                             \
        diff += (x) - M_PI;                                                 \
    time2 = clock();                                                        \
    printf("%s\t=> %e, time => %f\n", #x, diff, diffclock(time2, time1));   \
}

static inline double
diffclock(clock_t time1, clock_t time0)
{
    return (double) (time1 - time0) / CLOCKS_PER_SEC;
}

int
main()
{
    int i;
    clock_t time1, time2;
    double diff;

    /* Warmup. The atan2 case catches GCC's atan folding (which would
     * optimise the ``4 * atan(1) - M_PI'' to a no-op), if -fno-builtin
     * is not used. */
    TESTWITH(4 * atan(1))
    TESTWITH(4 * atan2(1, 1))

#if defined(__GNUC__) && (defined(__i386__) || defined(__amd64__))
    extern double fldpi();
    TESTWITH(fldpi())
#endif

    /* Actual tests start here. */
    TESTWITH(atan2(0, -1))
    TESTWITH(acos(-1))
    TESTWITH(2 * asin(1))
    TESTWITH(4 * atan2(1, 1))
    TESTWITH(4 * atan(1))

    return 0;
}

内联汇编的东西(fldpi.c)只适用于x86和x64系统:

double
fldpi()
{
    double pi;
    asm("fldpi" : "=t" (pi));
    return pi;
}

和一个构建脚本，构建我正在测试的所有配置(build.sh):

#!/bin/sh
gcc -O3 -Wall -c           -m32 -o fldpi-32.o fldpi.c
gcc -O3 -Wall -c           -m64 -o fldpi-64.o fldpi.c

gcc -O3 -Wall -ffast-math  -m32 -o pitimes1-32 pitimes.c fldpi-32.o
gcc -O3 -Wall              -m32 -o pitimes2-32 pitimes.c fldpi-32.o -lm
gcc -O3 -Wall -fno-builtin -m32 -o pitimes3-32 pitimes.c fldpi-32.o -lm
gcc -O3 -Wall -ffast-math  -m64 -o pitimes1-64 pitimes.c fldpi-64.o -lm
gcc -O3 -Wall              -m64 -o pitimes2-64 pitimes.c fldpi-64.o -lm
gcc -O3 -Wall -fno-builtin -m64 -o pitimes3-64 pitimes.c fldpi-64.o -lm

除了在各种编译器标志之间进行测试(我也比较了32位和64位，因为优化是不同的)，我还尝试切换测试的顺序。但是，atan2(0， -1)版本在每次测试中仍然名列前茅。

当前回答

BBP公式允许你计算第n位数字-以2为基数(或16)-甚至不需要麻烦之前的n-1位:)

2008-08-29 09:22:16

其他回答

我真的很喜欢这个程序，因为它通过观察它自己的面积来近似π。

IOCCC 1988: westley.c

#define _ -F<00||--F-OO--; int F=00,OO=00;main(){F_OO();printf("%1.3f\n",4.*-F/OO/OO);}F_OO() { _-_-_-_ _-_-_-_-_-_-_-_-_ _-_-_-_-_-_-_-_-_-_-_-_ _-_-_-_-_-_-_-_-_-_-_-_-_-_ _-_-_-_-_-_-_-_-_-_-_-_-_-_-_ _-_-_-_-_-_-_-_-_-_-_-_-_-_-_ _-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_ _-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_ _-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_ _-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_ _-_-_-_-_-_-_-_-_-_-_-_-_-_-_ _-_-_-_-_-_-_-_-_-_-_-_-_-_-_ _-_-_-_-_-_-_-_-_-_-_-_-_-_ _-_-_-_-_-_-_-_-_-_-_-_ _-_-_-_-_-_-_-_ _-_-_-_ }

2008-09-02 13:28:51

为了完整起见，一个c++模板版本，对于一个优化的构建，它将在编译时计算PI的近似值，并将内联到单个值。

#include <iostream>

template<int I>
struct sign
{
    enum {value = (I % 2) == 0 ? 1 : -1};
};

template<int I, int J>
struct pi_calc
{
    inline static double value ()
    {
        return (pi_calc<I-1, J>::value () + pi_calc<I-1, J+1>::value ()) / 2.0;
    }
};

template<int J>
struct pi_calc<0, J>
{
    inline static double value ()
    {
        return (sign<J>::value * 4.0) / (2.0 * J + 1.0) + pi_calc<0, J-1>::value ();
    }
};


template<>
struct pi_calc<0, 0>
{
    inline static double value ()
    {
        return 4.0;
    }
};

template<int I>
struct pi
{
    inline static double value ()
    {
        return pi_calc<I, I>::value ();
    }
};

int main ()
{
    std::cout.precision (12);

    const double pi_value = pi<10>::value ();

    std::cout << "pi ~ " << pi_value << std::endl;

    return 0;
}

注意，对于I > 10，优化构建可能会很慢，对于非优化运行也是如此。对于12次迭代，我相信大约有80k次调用value()(在没有内存的情况下)。

2009-12-22 15:40:04

如果你想计算π值的近似值(出于某种原因)，你应该尝试二进制提取算法。Bellard对BBP的改进给出了O(N²)中的PI。

如果你想获得π值的近似值来进行计算，那么:

PI = 3.141592654

当然，这只是一个近似值，并不完全准确。误差略大于0.00000000004102。(4个十万亿分之一，大约4/10,000,000,000)。

如果你想用π做数学运算，那就准备好铅笔和纸，或者电脑代数包，然后使用π的精确值π。

如果你真的想要一个公式，这个很有趣:

π = -i ln(-1)

2009-12-22 21:13:49

比GMPY2和MPmath内置更快:45分钟十亿:

我尝试了几种方法;Manchin, AGM和Chudnovsky兄弟。Chudnovsky和Binary Split是最快的: 我的github: https://github.com/Overboard-code/Pi-Pourri

我的Binary Split Chudnovsky的速度大约是内置gmpy2.const_pi()的两倍。MPmath.mp.pi()计算10亿需要50分钟，所以它几乎和Chudnovsky一样快。

我也非常感谢表演技巧。我不确定我的代码是否完美。它是100%准确的(所有公式都同意1亿)，但也许可以更快?

我尝试了gmpy2.const_pi()到1亿个数字，在同一台机器上，Chudnovsky花了300秒，而Chudnovsky花了150秒。Pi.txt和pi2.txt是一样的。

在不到一个小时的时间里，我在我的旧i7 16GB笔记本电脑上输入了10亿个数字。

以下是我尝试过的12种方法中最快的一种:

class PiChudnovsky:
    """Version of Chudnovsky Bros using Binary Splitting 
        So far this is the winner for fastest time to a million digits on my older intel i7
    """
    A = mpz(13591409)
    B = mpz(545140134)
    C = mpz(640320)
    D = mpz(426880)
    E = mpz(10005)
    C3_24  = pow(C, mpz(3)) // mpz(24)
    #DIGITS_PER_TERM = math.log(53360 ** 3) / math.log(10)  #=> 14.181647462725476
    DIGITS_PER_TERM = 14.181647462725476
    MMILL = mpz(1000000)

    def __init__(self,ndigits):
        """ Initialization
        :param int ndigits: digits of PI computation
        """
        self.ndigits = ndigits
        self.n      = mpz(self.ndigits // self.DIGITS_PER_TERM + 1)
        self.prec   = mpz((self.ndigits + 1) * LOG2_10)
        self.one_sq = pow(mpz(10),mpz(2 * ndigits))
        self.sqrt_c = isqrt(self.E * self.one_sq)
        self.iters  = mpz(0)
        self.start_time = 0

    def compute(self):
        """ Computation """
        try:
            self.start_time = time.time()
            logging.debug("Starting {} formula to {:,} decimal places"
                .format(name,ndigits) )
            __, q, t = self.__bs(mpz(0), self.n)  # p is just for recursion
            pi = (q * self.D * self.sqrt_c) // t
            logging.debug('{} calulation Done! {:,} iterations and {:.2f} seconds.'
                .format( name, int(self.iters),time.time() - self.start_time))
            get_context().precision= int((self.ndigits+10) * LOG2_10)
            pi_s = pi.digits() # digits() gmpy2 creates a string 
            pi_o = pi_s[:1] + "." + pi_s[1:]
            return pi_o,int(self.iters),time.time() - self.start_time
        except Exception as e:
            print (e.message, e.args)
            raise

    def __bs(self, a, b):
        """ PQT computation by BSA(= Binary Splitting Algorithm)
        :param int a: positive integer
        :param int b: positive integer
        :return list [int p_ab, int q_ab, int t_ab]
        """
        try:
            self.iters += mpz(1)
            if self.iters % self.MMILL  == mpz(0):
                logging.debug('Chudnovsky ... {:,} iterations and {:.2f} seconds.'
                    .format( int(self.iters),time.time() - self.start_time))
            if a + mpz(1) == b:
                if a == mpz(0):
                    p_ab = q_ab = mpz(1)
                else:
                    p_ab = mpz((mpz(6) * a - mpz(5)) * (mpz(2) * a - mpz(1)) * (mpz(6) * a - mpz(1)))
                    q_ab = pow(a,mpz(3)) * self.C3_24
                t_ab = p_ab * (self.A + self.B * a)
                if a & 1:
                    t_ab *= mpz(-1)
            else:
                m = (a + b) // mpz(2)
                p_am, q_am, t_am = self.__bs(a, m)
                p_mb, q_mb, t_mb = self.__bs(m, b)
                p_ab = p_am * p_mb
                q_ab = q_am * q_mb
                t_ab = q_mb * t_am + p_am * t_mb
            return [p_ab, q_ab, t_ab]
        except Exception as e:
            print (e.message, e.args)
            raise

以下是在45分钟内输出的10亿位数:

python pi-pourri.py -v -d 1,000,000,000 -a 10 

[INFO] 2022-10-03 09:22:51,860 <module>: MainProcess Computing π to 1,000,000,000 digits.
[DEBUG] 2022-10-03 09:25:00,543 compute: MainProcess Starting   Chudnovsky brothers  1988 
    π = (Q(0, N) / 12T(0, N) + 12AQ(0, N))**(C**(3/2))
 formula to 1,000,000,000 decimal places
[DEBUG] 2022-10-03 09:25:04,995 __bs: MainProcess Chudnovsky ... 1,000,000 iterations and 4.45 seconds.
[DEBUG] 2022-10-03 09:25:10,836 __bs: MainProcess Chudnovsky ... 2,000,000 iterations and 10.29 seconds.
[DEBUG] 2022-10-03 09:25:18,227 __bs: MainProcess Chudnovsky ... 3,000,000 iterations and 17.68 seconds.
[DEBUG] 2022-10-03 09:25:24,512 __bs: MainProcess Chudnovsky ... 4,000,000 iterations and 23.97 seconds.
[DEBUG] 2022-10-03 09:25:35,670 __bs: MainProcess Chudnovsky ... 5,000,000 iterations and 35.13 seconds.
[DEBUG] 2022-10-03 09:25:41,376 __bs: MainProcess Chudnovsky ... 6,000,000 iterations and 40.83 seconds.
[DEBUG] 2022-10-03 09:25:49,238 __bs: MainProcess Chudnovsky ... 7,000,000 iterations and 48.69 seconds.
[DEBUG] 2022-10-03 09:25:55,646 __bs: MainProcess Chudnovsky ... 8,000,000 iterations and 55.10 seconds.
[DEBUG] 2022-10-03 09:26:15,043 __bs: MainProcess Chudnovsky ... 9,000,000 iterations and 74.50 seconds.
[DEBUG] 2022-10-03 09:26:21,437 __bs: MainProcess Chudnovsky ... 10,000,000 iterations and 80.89 seconds.
[DEBUG] 2022-10-03 09:26:26,587 __bs: MainProcess Chudnovsky ... 11,000,000 iterations and 86.04 seconds.
[DEBUG] 2022-10-03 09:26:34,777 __bs: MainProcess Chudnovsky ... 12,000,000 iterations and 94.23 seconds.
[DEBUG] 2022-10-03 09:26:41,231 __bs: MainProcess Chudnovsky ... 13,000,000 iterations and 100.69 seconds.
[DEBUG] 2022-10-03 09:26:52,972 __bs: MainProcess Chudnovsky ... 14,000,000 iterations and 112.43 seconds.
[DEBUG] 2022-10-03 09:26:59,517 __bs: MainProcess Chudnovsky ... 15,000,000 iterations and 118.97 seconds.
[DEBUG] 2022-10-03 09:27:07,932 __bs: MainProcess Chudnovsky ... 16,000,000 iterations and 127.39 seconds.
[DEBUG] 2022-10-03 09:27:14,036 __bs: MainProcess Chudnovsky ... 17,000,000 iterations and 133.49 seconds.
[DEBUG] 2022-10-03 09:27:51,629 __bs: MainProcess Chudnovsky ... 18,000,000 iterations and 171.09 seconds.
[DEBUG] 2022-10-03 09:27:58,176 __bs: MainProcess Chudnovsky ... 19,000,000 iterations and 177.63 seconds.
[DEBUG] 2022-10-03 09:28:06,704 __bs: MainProcess Chudnovsky ... 20,000,000 iterations and 186.16 seconds.
[DEBUG] 2022-10-03 09:28:13,376 __bs: MainProcess Chudnovsky ... 21,000,000 iterations and 192.83 seconds.
[DEBUG] 2022-10-03 09:28:18,737 __bs: MainProcess Chudnovsky ... 22,000,000 iterations and 198.19 seconds.
[DEBUG] 2022-10-03 09:28:31,095 __bs: MainProcess Chudnovsky ... 23,000,000 iterations and 210.55 seconds.
[DEBUG] 2022-10-03 09:28:37,789 __bs: MainProcess Chudnovsky ... 24,000,000 iterations and 217.25 seconds.
[DEBUG] 2022-10-03 09:28:46,171 __bs: MainProcess Chudnovsky ... 25,000,000 iterations and 225.63 seconds.
[DEBUG] 2022-10-03 09:28:52,933 __bs: MainProcess Chudnovsky ... 26,000,000 iterations and 232.39 seconds.
[DEBUG] 2022-10-03 09:29:13,524 __bs: MainProcess Chudnovsky ... 27,000,000 iterations and 252.98 seconds.
[DEBUG] 2022-10-03 09:29:19,676 __bs: MainProcess Chudnovsky ... 28,000,000 iterations and 259.13 seconds.
[DEBUG] 2022-10-03 09:29:28,196 __bs: MainProcess Chudnovsky ... 29,000,000 iterations and 267.65 seconds.
[DEBUG] 2022-10-03 09:29:34,720 __bs: MainProcess Chudnovsky ... 30,000,000 iterations and 274.18 seconds.
[DEBUG] 2022-10-03 09:29:47,075 __bs: MainProcess Chudnovsky ... 31,000,000 iterations and 286.53 seconds.
[DEBUG] 2022-10-03 09:29:53,746 __bs: MainProcess Chudnovsky ... 32,000,000 iterations and 293.20 seconds.
[DEBUG] 2022-10-03 09:29:59,099 __bs: MainProcess Chudnovsky ... 33,000,000 iterations and 298.56 seconds.
[DEBUG] 2022-10-03 09:30:07,511 __bs: MainProcess Chudnovsky ... 34,000,000 iterations and 306.97 seconds.
[DEBUG] 2022-10-03 09:30:14,279 __bs: MainProcess Chudnovsky ... 35,000,000 iterations and 313.74 seconds.
[DEBUG] 2022-10-03 09:31:31,710 __bs: MainProcess Chudnovsky ... 36,000,000 iterations and 391.17 seconds.
[DEBUG] 2022-10-03 09:31:38,454 __bs: MainProcess Chudnovsky ... 37,000,000 iterations and 397.91 seconds.
[DEBUG] 2022-10-03 09:31:46,437 __bs: MainProcess Chudnovsky ... 38,000,000 iterations and 405.89 seconds.
[DEBUG] 2022-10-03 09:31:53,285 __bs: MainProcess Chudnovsky ... 39,000,000 iterations and 412.74 seconds.
[DEBUG] 2022-10-03 09:32:05,602 __bs: MainProcess Chudnovsky ... 40,000,000 iterations and 425.06 seconds.
[DEBUG] 2022-10-03 09:32:12,220 __bs: MainProcess Chudnovsky ... 41,000,000 iterations and 431.68 seconds.
[DEBUG] 2022-10-03 09:32:20,708 __bs: MainProcess Chudnovsky ... 42,000,000 iterations and 440.17 seconds.
[DEBUG] 2022-10-03 09:32:27,552 __bs: MainProcess Chudnovsky ... 43,000,000 iterations and 447.01 seconds.
[DEBUG] 2022-10-03 09:32:32,986 __bs: MainProcess Chudnovsky ... 44,000,000 iterations and 452.44 seconds.
[DEBUG] 2022-10-03 09:32:53,904 __bs: MainProcess Chudnovsky ... 45,000,000 iterations and 473.36 seconds.
[DEBUG] 2022-10-03 09:33:00,832 __bs: MainProcess Chudnovsky ... 46,000,000 iterations and 480.29 seconds.
[DEBUG] 2022-10-03 09:33:09,198 __bs: MainProcess Chudnovsky ... 47,000,000 iterations and 488.66 seconds.
[DEBUG] 2022-10-03 09:33:16,000 __bs: MainProcess Chudnovsky ... 48,000,000 iterations and 495.46 seconds.
[DEBUG] 2022-10-03 09:33:27,921 __bs: MainProcess Chudnovsky ... 49,000,000 iterations and 507.38 seconds.
[DEBUG] 2022-10-03 09:33:34,778 __bs: MainProcess Chudnovsky ... 50,000,000 iterations and 514.24 seconds.
[DEBUG] 2022-10-03 09:33:43,298 __bs: MainProcess Chudnovsky ... 51,000,000 iterations and 522.76 seconds.
[DEBUG] 2022-10-03 09:33:49,959 __bs: MainProcess Chudnovsky ... 52,000,000 iterations and 529.42 seconds.
[DEBUG] 2022-10-03 09:34:29,294 __bs: MainProcess Chudnovsky ... 53,000,000 iterations and 568.75 seconds.
[DEBUG] 2022-10-03 09:34:36,176 __bs: MainProcess Chudnovsky ... 54,000,000 iterations and 575.63 seconds.
[DEBUG] 2022-10-03 09:34:41,576 __bs: MainProcess Chudnovsky ... 55,000,000 iterations and 581.03 seconds.
[DEBUG] 2022-10-03 09:34:50,161 __bs: MainProcess Chudnovsky ... 56,000,000 iterations and 589.62 seconds.
[DEBUG] 2022-10-03 09:34:56,811 __bs: MainProcess Chudnovsky ... 57,000,000 iterations and 596.27 seconds.
[DEBUG] 2022-10-03 09:35:09,382 __bs: MainProcess Chudnovsky ... 58,000,000 iterations and 608.84 seconds.
[DEBUG] 2022-10-03 09:35:16,206 __bs: MainProcess Chudnovsky ... 59,000,000 iterations and 615.66 seconds.
[DEBUG] 2022-10-03 09:35:24,295 __bs: MainProcess Chudnovsky ... 60,000,000 iterations and 623.75 seconds.
[DEBUG] 2022-10-03 09:35:31,095 __bs: MainProcess Chudnovsky ... 61,000,000 iterations and 630.55 seconds.
[DEBUG] 2022-10-03 09:35:52,139 __bs: MainProcess Chudnovsky ... 62,000,000 iterations and 651.60 seconds.
[DEBUG] 2022-10-03 09:35:58,781 __bs: MainProcess Chudnovsky ... 63,000,000 iterations and 658.24 seconds.
[DEBUG] 2022-10-03 09:36:07,399 __bs: MainProcess Chudnovsky ... 64,000,000 iterations and 666.86 seconds.
[DEBUG] 2022-10-03 09:36:12,847 __bs: MainProcess Chudnovsky ... 65,000,000 iterations and 672.30 seconds.
[DEBUG] 2022-10-03 09:36:19,763 __bs: MainProcess Chudnovsky ... 66,000,000 iterations and 679.22 seconds.
[DEBUG] 2022-10-03 09:36:32,351 __bs: MainProcess Chudnovsky ... 67,000,000 iterations and 691.81 seconds.
[DEBUG] 2022-10-03 09:36:39,078 __bs: MainProcess Chudnovsky ... 68,000,000 iterations and 698.53 seconds.
[DEBUG] 2022-10-03 09:36:47,830 __bs: MainProcess Chudnovsky ... 69,000,000 iterations and 707.29 seconds.
[DEBUG] 2022-10-03 09:36:54,701 __bs: MainProcess Chudnovsky ... 70,000,000 iterations and 714.16 seconds.
[DEBUG] 2022-10-03 09:39:39,357 __bs: MainProcess Chudnovsky ... 71,000,000 iterations and 878.81 seconds.
[DEBUG] 2022-10-03 09:39:46,199 __bs: MainProcess Chudnovsky ... 72,000,000 iterations and 885.66 seconds.
[DEBUG] 2022-10-03 09:39:54,956 __bs: MainProcess Chudnovsky ... 73,000,000 iterations and 894.41 seconds.
[DEBUG] 2022-10-03 09:40:01,639 __bs: MainProcess Chudnovsky ... 74,000,000 iterations and 901.10 seconds.
[DEBUG] 2022-10-03 09:40:14,219 __bs: MainProcess Chudnovsky ... 75,000,000 iterations and 913.68 seconds.
[DEBUG] 2022-10-03 09:40:19,680 __bs: MainProcess Chudnovsky ... 76,000,000 iterations and 919.14 seconds.
[DEBUG] 2022-10-03 09:40:26,625 __bs: MainProcess Chudnovsky ... 77,000,000 iterations and 926.08 seconds.
[DEBUG] 2022-10-03 09:40:35,212 __bs: MainProcess Chudnovsky ... 78,000,000 iterations and 934.67 seconds.
[DEBUG] 2022-10-03 09:40:41,914 __bs: MainProcess Chudnovsky ... 79,000,000 iterations and 941.37 seconds.
[DEBUG] 2022-10-03 09:41:03,218 __bs: MainProcess Chudnovsky ... 80,000,000 iterations and 962.68 seconds.
[DEBUG] 2022-10-03 09:41:10,213 __bs: MainProcess Chudnovsky ... 81,000,000 iterations and 969.67 seconds.
[DEBUG] 2022-10-03 09:41:18,344 __bs: MainProcess Chudnovsky ... 82,000,000 iterations and 977.80 seconds.
[DEBUG] 2022-10-03 09:41:25,261 __bs: MainProcess Chudnovsky ... 83,000,000 iterations and 984.72 seconds.
[DEBUG] 2022-10-03 09:41:37,663 __bs: MainProcess Chudnovsky ... 84,000,000 iterations and 997.12 seconds.
[DEBUG] 2022-10-03 09:41:44,680 __bs: MainProcess Chudnovsky ... 85,000,000 iterations and 1004.14 seconds.
[DEBUG] 2022-10-03 09:41:53,411 __bs: MainProcess Chudnovsky ... 86,000,000 iterations and 1012.87 seconds.
[DEBUG] 2022-10-03 09:41:58,926 __bs: MainProcess Chudnovsky ... 87,000,000 iterations and 1018.38 seconds.
[DEBUG] 2022-10-03 09:42:05,858 __bs: MainProcess Chudnovsky ... 88,000,000 iterations and 1025.32 seconds.
[DEBUG] 2022-10-03 09:42:46,163 __bs: MainProcess Chudnovsky ... 89,000,000 iterations and 1065.62 seconds.
[DEBUG] 2022-10-03 09:42:53,054 __bs: MainProcess Chudnovsky ... 90,000,000 iterations and 1072.51 seconds.
[DEBUG] 2022-10-03 09:43:02,030 __bs: MainProcess Chudnovsky ... 91,000,000 iterations and 1081.49 seconds.
[DEBUG] 2022-10-03 09:43:09,192 __bs: MainProcess Chudnovsky ... 92,000,000 iterations and 1088.65 seconds.
[DEBUG] 2022-10-03 09:43:21,533 __bs: MainProcess Chudnovsky ... 93,000,000 iterations and 1100.99 seconds.
[DEBUG] 2022-10-03 09:43:28,643 __bs: MainProcess Chudnovsky ... 94,000,000 iterations and 1108.10 seconds.
[DEBUG] 2022-10-03 09:43:37,372 __bs: MainProcess Chudnovsky ... 95,000,000 iterations and 1116.83 seconds.
[DEBUG] 2022-10-03 09:43:44,558 __bs: MainProcess Chudnovsky ... 96,000,000 iterations and 1124.02 seconds.
[DEBUG] 2022-10-03 09:44:06,555 __bs: MainProcess Chudnovsky ... 97,000,000 iterations and 1146.01 seconds.
[DEBUG] 2022-10-03 09:44:12,220 __bs: MainProcess Chudnovsky ... 98,000,000 iterations and 1151.68 seconds.
[DEBUG] 2022-10-03 09:44:19,278 __bs: MainProcess Chudnovsky ... 99,000,000 iterations and 1158.74 seconds.
[DEBUG] 2022-10-03 09:44:28,323 __bs: MainProcess Chudnovsky ... 100,000,000 iterations and 1167.78 seconds.
[DEBUG] 2022-10-03 09:44:35,211 __bs: MainProcess Chudnovsky ... 101,000,000 iterations and 1174.67 seconds.
[DEBUG] 2022-10-03 09:44:48,331 __bs: MainProcess Chudnovsky ... 102,000,000 iterations and 1187.79 seconds.
[DEBUG] 2022-10-03 09:44:54,835 __bs: MainProcess Chudnovsky ... 103,000,000 iterations and 1194.29 seconds.
[DEBUG] 2022-10-03 09:45:03,869 __bs: MainProcess Chudnovsky ... 104,000,000 iterations and 1203.33 seconds.
[DEBUG] 2022-10-03 09:45:10,967 __bs: MainProcess Chudnovsky ... 105,000,000 iterations and 1210.42 seconds.
[DEBUG] 2022-10-03 09:46:32,760 __bs: MainProcess Chudnovsky ... 106,000,000 iterations and 1292.22 seconds.
[DEBUG] 2022-10-03 09:46:39,872 __bs: MainProcess Chudnovsky ... 107,000,000 iterations and 1299.33 seconds.
[DEBUG] 2022-10-03 09:46:48,948 __bs: MainProcess Chudnovsky ... 108,000,000 iterations and 1308.41 seconds.
[DEBUG] 2022-10-03 09:46:54,611 __bs: MainProcess Chudnovsky ... 109,000,000 iterations and 1314.07 seconds.
[DEBUG] 2022-10-03 09:47:01,727 __bs: MainProcess Chudnovsky ... 110,000,000 iterations and 1321.18 seconds.
[DEBUG] 2022-10-03 09:47:14,525 __bs: MainProcess Chudnovsky ... 111,000,000 iterations and 1333.98 seconds.
[DEBUG] 2022-10-03 09:47:21,682 __bs: MainProcess Chudnovsky ... 112,000,000 iterations and 1341.14 seconds.
[DEBUG] 2022-10-03 09:47:30,610 __bs: MainProcess Chudnovsky ... 113,000,000 iterations and 1350.07 seconds.
[DEBUG] 2022-10-03 09:47:37,176 __bs: MainProcess Chudnovsky ... 114,000,000 iterations and 1356.63 seconds.
[DEBUG] 2022-10-03 09:47:59,642 __bs: MainProcess Chudnovsky ... 115,000,000 iterations and 1379.10 seconds.
[DEBUG] 2022-10-03 09:48:06,702 __bs: MainProcess Chudnovsky ... 116,000,000 iterations and 1386.16 seconds.
[DEBUG] 2022-10-03 09:48:15,483 __bs: MainProcess Chudnovsky ... 117,000,000 iterations and 1394.94 seconds.
[DEBUG] 2022-10-03 09:48:22,537 __bs: MainProcess Chudnovsky ... 118,000,000 iterations and 1401.99 seconds.
[DEBUG] 2022-10-03 09:48:35,714 __bs: MainProcess Chudnovsky ... 119,000,000 iterations and 1415.17 seconds.
[DEBUG] 2022-10-03 09:48:41,321 __bs: MainProcess Chudnovsky ... 120,000,000 iterations and 1420.78 seconds.
[DEBUG] 2022-10-03 09:48:48,408 __bs: MainProcess Chudnovsky ... 121,000,000 iterations and 1427.87 seconds.
[DEBUG] 2022-10-03 09:48:57,138 __bs: MainProcess Chudnovsky ... 122,000,000 iterations and 1436.60 seconds.
[DEBUG] 2022-10-03 09:49:04,328 __bs: MainProcess Chudnovsky ... 123,000,000 iterations and 1443.79 seconds.
[DEBUG] 2022-10-03 09:49:46,274 __bs: MainProcess Chudnovsky ... 124,000,000 iterations and 1485.73 seconds.
[DEBUG] 2022-10-03 09:49:52,833 __bs: MainProcess Chudnovsky ... 125,000,000 iterations and 1492.29 seconds.
[DEBUG] 2022-10-03 09:50:01,786 __bs: MainProcess Chudnovsky ... 126,000,000 iterations and 1501.24 seconds.
[DEBUG] 2022-10-03 09:50:08,975 __bs: MainProcess Chudnovsky ... 127,000,000 iterations and 1508.43 seconds.
[DEBUG] 2022-10-03 09:50:21,850 __bs: MainProcess Chudnovsky ... 128,000,000 iterations and 1521.31 seconds.
[DEBUG] 2022-10-03 09:50:28,962 __bs: MainProcess Chudnovsky ... 129,000,000 iterations and 1528.42 seconds.
[DEBUG] 2022-10-03 09:50:34,594 __bs: MainProcess Chudnovsky ... 130,000,000 iterations and 1534.05 seconds.
[DEBUG] 2022-10-03 09:50:43,647 __bs: MainProcess Chudnovsky ... 131,000,000 iterations and 1543.10 seconds.
[DEBUG] 2022-10-03 09:50:50,724 __bs: MainProcess Chudnovsky ... 132,000,000 iterations and 1550.18 seconds.
[DEBUG] 2022-10-03 09:51:12,742 __bs: MainProcess Chudnovsky ... 133,000,000 iterations and 1572.20 seconds.
[DEBUG] 2022-10-03 09:51:19,799 __bs: MainProcess Chudnovsky ... 134,000,000 iterations and 1579.26 seconds.
[DEBUG] 2022-10-03 09:51:28,824 __bs: MainProcess Chudnovsky ... 135,000,000 iterations and 1588.28 seconds.
[DEBUG] 2022-10-03 09:51:35,324 __bs: MainProcess Chudnovsky ... 136,000,000 iterations and 1594.78 seconds.
[DEBUG] 2022-10-03 09:51:48,419 __bs: MainProcess Chudnovsky ... 137,000,000 iterations and 1607.88 seconds.
[DEBUG] 2022-10-03 09:51:55,634 __bs: MainProcess Chudnovsky ... 138,000,000 iterations and 1615.09 seconds.
[DEBUG] 2022-10-03 09:52:04,435 __bs: MainProcess Chudnovsky ... 139,000,000 iterations and 1623.89 seconds.
[DEBUG] 2022-10-03 09:52:11,583 __bs: MainProcess Chudnovsky ... 140,000,000 iterations and 1631.04 seconds.
[DEBUG] 2022-10-03 09:52:17,222 __bs: MainProcess Chudnovsky ... 141,000,000 iterations and 1636.68 seconds.
[DEBUG] 2022-10-03 10:02:43,939 compute: MainProcess    Chudnovsky brothers  1988 
    π = (Q(0, N) / 12T(0, N) + 12AQ(0, N))**(C**(3/2))
 calulation Done! 141,027,339 iterations and 2263.39 seconds.
[INFO] 2022-10-03 10:09:07,119 <module>: MainProcess Last 5 digits of π were 45519 as expected at offset 999,999,995
[INFO] 2022-10-03 10:09:07,119 <module>: MainProcess Calculated π to 1,000,000,000 digits using a formula of:
 10     Chudnovsky brothers  1988 
    π = (Q(0, N) / 12T(0, N) + 12AQ(0, N))**(C**(3/2))
 
[INFO] 2022-10-03 10:09:07,120 <module>: MainProcess Calculation took 141,027,339 iterations and 0:44:06.398345.

math_pi。Pi (b = 1000000) 快到一百万。大约快40倍。但它不能达到十亿，一百万是最多的数字。

GMPY内置看起来像:

python pi-pourri.py -v -d 1,000,000,000 -a 11
[INFO] 2022-10-03 14:33:34,729 <module>: MainProcess Computing π to 1,000,000,000 digits.
[DEBUG] 2022-10-03 14:33:34,729 compute: MainProcess Starting   const_pi() function from the gmpy2 library formula to 1,000,000,000 decimal places
[DEBUG] 2022-10-03 15:46:46,575 compute: MainProcess    const_pi() function from the gmpy2 library calulation Done! 1 iterations and 4391.85 seconds.
[INFO] 2022-10-03 15:46:46,575 <module>: MainProcess Last 5 digits of π were 45519 as expected at offset 999,999,995
[INFO] 2022-10-03 15:46:46,575 <module>: MainProcess Calculated π to 1,000,000,000 digits using a formula of:
 11     const_pi() function from the gmpy2 library 
[INFO] 2022-10-03 15:46:46,575 <module>: MainProcess Calculation took 1 iterations and 1:13:11.845652.

内置的MPmath几乎一样快。慢约12%(6分钟):

python pi-pourri.py -v -a 12 -d 1,000,000,000  
[INFO] 2022-10-04 09:10:37,085 <module>: MainProcess Computing π to 1,000,000,000 digits.
[DEBUG] 2022-10-04 09:10:37,085 compute: MainProcess Starting   mp.pi() function from the mpmath library formula to 1,000,000,000 decimal places
[DEBUG] 2022-10-04 10:01:25,321 compute: MainProcess    mp.pi() function from the mpmath library calulation Done! 1 iterations and 3048.22 seconds.
[INFO] 2022-10-04 10:01:25,338 <module>: MainProcess Last 5 digits of π were 45519 as expected at offset 999,999,995
[INFO] 2022-10-04 10:01:25,340 <module>: MainProcess Calculated π to 1,000,000,000 digits using a formula of:
 12     mp.pi() function from the mpmath library 
[INFO] 2022-10-04 10:01:25,343 <module>: MainProcess Calculation took 1 iterations and 0:50:48.250337.
2022-09-19 18:06:33

我总是使用acos(-1)，而不是将π定义为常数。

2009-03-08 03:02:12

推荐文章

aliyun

最新文章

标签

2024 code 京ICP备15047053号-1