Question

我曾尝试为卡方PDF编写函数;但是我收到以下错误：

Q4.c: In function ‘GAMMA’:
Q4.c:31:2: error: expected identifier or ‘(’ before ‘long’
Q4.c:37:2: error: expected ‘(’ before ‘{’ token
Q4.c:38:3: error: ‘factor’ undeclared (first use in this function)
Q4.c:38:3: note: each undeclared identifier is reported only once for each function it appears in
Q4.c:43:4: error: ‘multiplier’ undeclared (first use in this function)

我无法弄清楚为什么会收到此错误。如果您提供一些建议或见解，我将不胜感激。

#include <stdio.h>
#include <math.h>
#include <limits.h>
#include <stdlib.h>
long double factorial (long double);
//Now we define it,
long double
factorial(long double n)
{
    //Here s is the free parameter which is increased by one in each step and
    //pro is the initial product and by setting pro to be 0 we also cover the
    //case of zero factorial.
    int s = 1;
    long double pro = 1;
    //Here pro stands for product.
    if (n < 0)
        printf("Factorial is not defined for a negative number \n");
    else {
    while (n >= s) { 
    pro *= s;
    s++;
    }
    return pro;
    }
}
long double GAMMA(int);
long double 
GAMMA(int v)
{
    int i = 1,
    long double factor, multiplier =  sqrtl(M_PI);
    if((v % 2) == 0)
    {
        return factorial((v / 2) - 1);
    }
    else if
    {
        factor = (v / 2) - i;
        while(v / 2 - (i + 1) > 0)
        {
            i++;
            factor = v / 2 - i; 
            multiplier *= factor;
        }
        return multiplier;
    }
}
long double ChisquarePDF(long double, int);
long double
ChisquarePDF(long double x, int v)
{
    return powl(x, v/2 - 1) / ( powl(2, v/2) * GAMMA(v / 2) * expl(x / 2)) ;
}
int main()
{
    printf("%Lf \n", GAMMA(5));
}

Answer 1

此声明：

int i = 1,
long double factor, multiplier =  sqrtl(M_PI);

应该用分号分隔：

int i = 1;
long double factor, multiplier =  sqrtl(M_PI);

Answer 2

在这一行：

int i = 1,
long double factor, multiplier =  sqrtl(M_PI);

,之后，您有一个逗号;而不是分号int i=1。

接下来这一行：

  else if

if缺少它的表达式来评估。如果没有任何表达，请在那里只写else。

编译期间出错？

2 个答案: