c - PIL 逊系数计算数组

Question

我正在编写一个程序来计算 c 中的 PIL 逊系数，但我遇到了一些麻烦，我不确定问题是什么，这是我的代码:

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

#define aSize 2000000


double mean(double* mean_array){
    double mean = 0;

    for (int i=0; i<aSize; i++){
        mean = mean + mean_array[i];
    }


    mean = mean/aSize;

    return mean;

}

double stan_dev_seq(double stan_array[], double stan_mean){

    double a = 0;

    for (int i=0; i<aSize; i++){
        a = a + pow((stan_array[i]-stan_mean), 2);
    }

    a = a/aSize;

    a = sqrt(a);

    return a;
}

int pearson_seq(void){

    clock_t begin, end;
    double time_spent;

    begin = clock();

    double *a;
    a = malloc(sizeof(double)*aSize);


    double *b;
    b = malloc(sizeof(double)*aSize);

    double mean_a;
    double mean_b;

    for (int i=0; i<aSize; i++){
        a[i] = sin(i);
        b[i] = sin(i+2);    

    }

    mean_a = mean(a);
    mean_b = mean(b);



    double stan_dev_a = stan_dev_seq(a, mean_a);
    double stan_dev_b = stan_dev_seq(b, mean_b);

    double pearson_numer;

    for(int i=0; i<aSize; i++){
        pearson_numer = pearson_numer + ((a[i]-mean_a)*(b[i]-mean_b));
    }

    pearson_numer = pearson_numer/aSize;

    double pearson_coef = pearson_numer/(stan_dev_a*stan_dev_b);

    printf("%s %G\n", "The Pearson Coefficient is: ", pearson_coef);

    end = clock();

    time_spent = (double)(end - begin) / CLOCKS_PER_SEC;


    printf("%f %s\n", end, "ms");
    printf("%f %s\n", begin, "ms");
    printf("%f %s\n", time_spent, "ms");



    free(a);
    free(b);

    return 0;
}

int main(void) {

    pearson_seq();

return 0;
} 

如果我运行该程序，我会得到一个不正确的系数值，然后是一个段错误，这对我来说真的毫无意义。

如果我打印数组的大小，我得到的值与数组大小无关。

如有任何帮助，我们将不胜感激。

Answer 1

for (int i=0; i<sizeof(mean_array); i++){

数组在传递给函数时会衰减为指针，因此 sizeof(mean_array) 相当于 sizeof(double) 这不是您想要的。在附加函数参数中传递数组大小。