双精度*和双精度到二进制运算符的无效操作数

Question

编程和为类编写C代码的新手。 我的程序假设从.txt文件中获取数据，计算，然后将结果打印到.txt文件中。

我得到：

双精度*和双精度到二进制运算符的无效操作数

在第 fscanf(therm, "%lf %lf",&temp &con); 行(底部附近的for环(

/* Preprocessor directives */
#include <stdio.h>
#include <math.h>
#define inputfile "c:\engr 200\thermal.txt"
#define outputfile "c:\engr 200\results.txt"
/*Main function*/
int main (void)
{
    /*Declare and intialize variables*/
    double temp, sumtemp = 0.0, con, sumcon = 0.0, tem_con, sumtem_con =
        0.0, tsq, sumtsq = 0.0;
    int i, ndata;
    FILE *therm, *res;
    /*Open files*/
    therm = fopen (inputfile, "r");
    res = fopen (outputfile, "w");
    /*Print output headings*/
    printf ("******************************************");
    printf ("nTEMPERATURE vs THERMAL CONDUCTIVITY");
    printf ("nby ");
    printf ("nnTemp    Conduct    Temp Sqrd    Temp*Conduct");
    /* Verify input file and read control number */
    // NOTE: unmatched 'else' followed, presuming a
    //       test for 'therm'
    if (!therm)
    {
        printf ("nnnn   ERROR OPENING INPUT FILE.");
        printf ("nn   PROGRAM TERMINATED.nnn");
        return 0;
    }
    else
    {
        /* Read control number */
        fscanf (therm, "%i", &ndata);
        /* Compute temp and conductivity data and print results */
        for (i = 1; i <= ndata; i++) {
            fscanf (therm, "%lf %lf", &temp & con);
            sumtemp = sumtemp + temp;
            sumcon = sumcon + con;
            sumtsq = sumtsq + pow (temp, 2);
            sumtem_con = sumtem_con + temp * con;
            printf ("n%3.0f   %5.1f   %6.1f  %6.1f", sumtemp, sumcon, sumtsq,
                    sumtem_con);
            fprintf (res, "%3.0f   %5.1f   %6.1f  %6.1f", sumtemp, sumcon,
                    sumtsq, sumtem_con);
        }
    }
    /*Close the input file*/
    fclose (therm);
    fclose (res);
    /*Exit the program*/
    return 0;
}

你能帮我诊断这个错误吗？

Answer 1

您错过了两个变量之间的逗号，并且 if 语句也丢失了。

fscanf(therm, "%lf %lf", &temp &con);

这应该是

fscanf(therm, "%lf %lf", &temp, &con);

应该有一个 if 语句。

/* Verify input file and read control number */