数字信号处理

产生(a, b)区间上均匀分布的随机数

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <math.h>
#include <ctype.h>

// Xi = (axi-1 +c)(mod M)
// Yi = xi/M
// a = 2045, c = 1, M=2^20, Zi = a + (a - b)Yi
double uniform(double a, double b, long int *seed)
{
    double t;
    *seed = 2045 * (*seed) + 1;
    *seed = *seed - (*seed/1048576) * 1048576;

    t = (*seed)/1048576.0;
    t = a + (b - a) * t;
    return t;
}

int main(int argc , char **argv)
{
    double a, b, x ;
    int i, j;
    long int s;

    a = 0.0; b = 1.0; s = 13576;


    for(int i = 0; i < 10; i++)
    {
        for(int j = 0; j < 5; j++)
        {
            x = uniform(a, b , &s);
            printf("%13.7f", x);
        }

        printf("\n");
    }
    return 0;
}


    0.4767847    0.0247250    0.5625448    0.4041634    0.5140734
    0.2800465    0.6950178    0.3114319    0.8782053    0.9298382
    0.5190802    0.5189323    0.2166414    0.0317173    0.8618803
    0.5452194    0.9737177    0.2526760    0.7224417    0.3932228
    0.1406450    0.6190815    0.0216627    0.3002472    0.0055094
    0.2666759    0.3523169    0.4879723    0.9032717    0.1905766
    0.7290525    0.9124527    0.9657679    0.9952755    0.3383932
    0.0141182    0.8717089    0.6446400    0.2887373    0.4677734
    0.5966806    0.2119122    0.3603582    0.9325981    0.1631441
    0.6297092    0.7554045    0.8021469    0.3904352    0.4400234