C gnuplot无法读取.dat文件

2天以来，我一直被这个错误“gnuplot:无法读取数据.dat”所困扰

我已经把文件路径也，但仍然是错误的到来。我搜索了互联网，我没有得到它

多谢各位

void plotgraph(float *xvals, float *yvals, float *x1vals, int NUM_POINTS)
{

 int NUM_COMMANDS = 4;
//char * commandsForGnuplot[] = { "set title \"Concatenated Coding+OFDM[QPSK]\"", "set ylabel 'BER'", "set xlabel 'SNR'", "plot '\C:\\Users\\shreyasn\\Documents\\Visual Studio 2013\\Projects\\Project1\\Project1\\data.temp\' with lines" };
//FILE * temp = fopen_s(&temp, "%temp%\\data.temp", "w");
//char *commandsForGnuplot[] = { "set title \"Concatenated Coding+OFDM[QPSK]\"", "set ylabel 'BER'", "set xlabel 'SNR'", "set logscale y", "set nologscale x", "plot 'data.temp' with lines title 'After coding' , \ 'data.temp1' with lines title 'Before coding'" };
// double xvals[NUM_POINTS] = {1.0, 2.0, 3.0, 4.0, 5.0};
//double yvals[NUM_POINTS] = {5.0 ,3.0, 1.0, 3.0, 5.0};
int i;
for (i = 0; i < NUM_POINTS; i++)
{
    printf("time: %f decod: %f encod: %f \n", xvals[i], x1vals[i], yvals[i]); //Write the data to a temporary file
}

errno_t err;
FILE *pipe;
FILE *temp9;
if ((err = fopen_s(&temp9, "data.dat", "w+")) != 0)
    printf("File not opened\n");
if (temp9 == NULL) { 
    printf("Error\n");
}

char * commandsForGnuplot[] = { "set title \"Concatenated Coding+OFDM[QPSK]\"", "set ylabel 'BER'", "set xlabel 'SNR'","plot '\C:\\Users\\shreyasn\\Documents\\Visual Studio 2013\\Projects\\Project1\\Project1\\data.dat\' using 1:2 with lines" };
//char * commandsForGnuplot[] = { "set title \"Concatenated Coding+OFDM[QPSK]\"", "set ylabel 'BER'", "set xlabel 'SNR'", "plot 'data.dat' with lines" };
//FILE * temp1 = fopen_s(&temp1,"data.temp1", "w");
//char *path = "C:\\Program Files (x86)\\gnuplot\\bin";
pipe = _popen("\"C:\\gnuplot\\binary\\gnuplot.exe\" -persistent", "w");
//Opens an interface that one can use to send commands as if they were typing into the
//    gnuplot command line.  "The -persistent" keeps the plot open even after your
//    C program terminates.
//




for (i = 0; i < NUM_POINTS; i++)
{
    fprintf(temp9, "%f %f \n", xvals[i], yvals[i]); //Write the data to a temporary file
    //fprintf(temp1, "%lf %lf \n", xvals[i], x1vals[i]); //Write the data to a temporary file
}

fclose(temp9);
fflush(temp9);

for (i = 0; i < NUM_COMMANDS; i++)
{
    fprintf(pipe, "%s \n", commandsForGnuplot[i]); //Send commands to gnuplot one by one.
}
fflush(pipe);

}

void绘图仪（浮点*xVAL、浮点*yVAL、浮点*x1VAL、整数点）
{
int NUM_命令=4；
//char*commandsForGnuplot[]={“set title\”级联编码+OFDM[QPSK]\，“set ylabel'BER'，“set xlabel'SNR'，“plot'\C:\\Users\\shryasn\\Documents\\visualstudio 2013\\Projects\\Project1\\Project1\\data.temp\'带行“}；
//文件*temp=fopen_s（&temp，“%temp%\\data.temp”，“w”）；
//char*commandsForGnuplot[]={“set title\”级联编码+OFDM[QPSK]\”，“set ylabel'BER'”，“set xlabel'SNR'”，“set logscale y y”，“set nologscale x”，“plot'data.temp'带有行标题'After Coding'，“data.temp1'带有行标题'Before Coding'”；
//双xvals[NUM_POINTS]={1.0,2.0,3.0,4.0,5.0}；
//双yvals[NUM_POINTS]={5.0,3.0,1.0,3.0,5.0}；
int i；
对于（i=0；i

注：fd[0]设置为读取，fd[1]设置为写入

数组中的第一个整数（元素0）被设置并打开以进行读取，而第二个整数（元素1）被设置并打开以进行写入。从视觉上讲，fd1的输出成为fd0的输入。同样，通过管道传输的所有数据都会通过内核

    #include <stdio.h>
    #include <unistd.h>
    #include <sys/types.h>

    main()
    {
            int     fd[2];

            pipe(fd);
            .
            .
    }

#包括
#包括
#包括
main（）
{
int-fd[2]；
管道（fd）；
.
.
}

fopen上的文档说明了有关模式字符串的以下内容： （还有其他允许的模式字符串，但以下内容似乎是 （最有用）

“r+” 为阅读和写作打开。（文件必须存在。）

“w+” 打开一个空文件进行读取和写入。 如果文件存在，其内容将被销毁

So I suggest using the "r+" mode string rather than the "w+" mode string

the failure to open suggests that the user does not have
permission to overwrite the file.

---

“pipe”是C中的一个系统调用，请使用不同的名称如果文件没有打开，那么我怀疑程序应该退出，而不是继续下一个语句在文件关闭后不能刷新文件。（并且关闭会执行刷新）此线段：“char*commandsForGnuplot[]”可能应该是：“char**commandsForGnuplot[][]”，并且实际的命令应该相应地格式化。即{“command1”}、{“command2”}、…}；文件名中的第一个字符是错误的反斜杠，不需要转义单引号。应该是

“plot'C:\\Users…”

。然后如何获得权限

So I suggest using the "r+" mode string rather than the "w+" mode string

the failure to open suggests that the user does not have
permission to overwrite the file.