#define MBIG 1000000000
#define MSEED 161803398
#define MZ 0
#define FAC 1.0E-9
double    CMCMie::RandomGen(char Type, long Seed, long *Status)
{
    static long i1, i2, ma[56];   /* ma[0] is not used. */
    long        mj, mk;
    short       i, ii;

    if (Type == 0) {              /* set seed. */
        mj = MSEED - (Seed < 0 ? -Seed : Seed);
        mj %= MBIG;
        ma[55] = mj;
        mk = 1;
        for (i = 1; i <= 54; i++)
        {
            ii = (21 * i) % 55;
            ma[ii] = mk;
            mk = mj - mk;
            if (mk < MZ)
                mk += MBIG;
            mj = ma[ii];
        }
        for (ii = 1; ii <= 4; ii++)
            for (i = 1; i <= 55; i++) {
                ma[i] -= ma[1 + (i + 30) % 55];
                if (ma[i] < MZ)
                    ma[i] += MBIG;
            }
            i1 = 0;
            i2 = 31;
    } else if (Type == 1) {       /* get a number. */
        if (++i1 == 56)
            i1 = 1;
        if (++i2 == 56)
            i2 = 1;
        mj = ma[i1] - ma[i2];
        if (mj < MZ)
            mj += MBIG;
        ma[i1] = mj;
        return (mj * FAC);
    } else if (Type == 2) {       /* get status. */
        for (i = 0; i < 55; i++)
            Status[i] = ma[i + 1];
        Status[55] = i1;
        Status[56] = i2;
    } else if (Type == 3) {       /* restore status. */
        for (i = 0; i < 55; i++)
            ma[i + 1] = Status[i];
        i1 = Status[55];
        i2 = Status[56];
    } else
        AfxMessageBox(_T("Wrong parameter to RandomGen()."));
    return (0);

看上去应该是随机数的计算公式~是模拟产生随机数~~~~通过Seed的参数来决定随机数序列~~~因为该序列其周期性较长~所以看上去像是随机数了~~实质Seed的值不变该序列就不会变~严格来说是"伪随机数"~当然这还是带有很强的随机性质的~~~

感觉常用的rand函数算法应该是类似这东东~~~

请问一下，你能适当的解释一下这个程序不？运行起来有好几个错的，表示完全看不懂！！！谢谢！！！

可以简单转化为c 代码  如何调用却是不会

#include <stdio.h>

#define MBIG 1000000000
#define MSEED 161803398
#define MZ 0
#define FAC 1.0E-9

double  RandomGen(char Type, long Seed, long *Status)
{
    static long i1, i2, ma[56];   /* ma[0] is not used. */
    long        mj, mk;
    short       i, ii;

    if (Type == 0) {              /* set seed. */
        mj = MSEED - (Seed < 0 ? -Seed : Seed);
        mj %= MBIG;
        ma[55] = mj;
        mk = 1;
        for (i = 1; i <= 54; i++)
        {
            ii = (21 * i) % 55;
            ma[ii] = mk;
            mk = mj - mk;
            if (mk < MZ)
                mk += MBIG;
            mj = ma[ii];
        }
        for (ii = 1; ii <= 4; ii++)
            for (i = 1; i <= 55; i++) {
                ma[i] -= ma[1 + (i + 30) % 55];
                if (ma[i] < MZ)
                    ma[i] += MBIG;
            }
            i1 = 0;
            i2 = 31;
    } else if (Type == 1) {       /* get a number. */
        if (++i1 == 56)
            i1 = 1;
        if (++i2 == 56)
            i2 = 1;
        mj = ma[i1] - ma[i2];
        if (mj < MZ)
            mj += MBIG;
        ma[i1] = mj;
        return (mj * FAC);
    } else if (Type == 2) {       /* get status. */
        for (i = 0; i < 55; i++)
            Status[i] = ma[i + 1];
        Status[55] = i1;
        Status[56] = i2;
    } else if (Type == 3) {       /* restore status. */
        for (i = 0; i < 55; i++)
            ma[i + 1] = Status[i];
        i1 = Status[55];
        i2 = Status[56];
    } else
        printf("Wrong parameter to RandomGen().");
}
int main()
{
    return 0;
}

 

  } else if (Type == 1) {       /* get a number. */
        if (++i1 == 56)
            i1 = 1;
        if (++i2 == 56)
            i2 = 1;
        mj = ma[i1] - ma[i2];
        if (mj < MZ)
            mj += MBIG;
        ma[i1] = mj;
        return (mj * FAC);

这里i1 i2好像没有赋予初值~~~这个程序本身没有问题么？~~~

如果可以的话要找个完整的实测程序来看看效果才行~~光说很多东西说不清~~~

[此贴子已经被作者于2017-5-16 17:29编辑过]

好吧！！！