c - gsl_matrix_fscanf(文件，矩阵)错误

Question

所以现在我只是想获取一个虚拟数据文件，

 1.30640 1
 0.91751 1
 0.49312 1
 0.49312 0
 1.79859 1
 1.86360 1
 0.12313 1
 0.12313 0
 -0.19091 1
 1.82377 1
 0.63205 1
 0.63205 0
 1.23357 1
 0.62110 1
 0.80438 1

目前将其存储为 gal_matrix 以供稍后操作。下面的代码现在很简单，给定一个数据文件名，找出它的长度(即行数)，初始化一个 gsl_matrix 结构，然后尝试将文本文件扫描到该矩阵中，称为链。

#include <stdio.h>          // Needed for printf() and feof()
#include <math.h>           // Needed for pow().   
#include <stdlib.h>         // Needed for exit() and atof()
#include <string.h>         // Needed for strcmp()
#include <gsl/gsl_matrix.h> // Needed for matrix manipulations

/*------------ Defines -----------------------------------------------------------------*/
#define MAX_SIZE  10000000   // Maximum size of the time series array
#define NUM_LAG   1000       // Number of lags to calculate for


/*
 *----------------------------------------------------------------------------------------
 * Main program
 *----------------------------------------------------------------------------------------
 */
int main(int argc, char* argv[]) {

//--------Initialization--------------------------------------------------------------
    double ac_value;      // computed autocorrelation value
    int i,j;              // Loop counter
    long int N;
    double mean, variance;
    gsl_matrix * chains;

    char filename[100];
    FILE* in_file;      // input file
    FILE* out_file;     // output file

    int no_params;      // number of parameters to calculate autocorrelation for
    int first_column;   // Which column first corresponds to a chain
    int ch;             // to determine number of samples in file

    printf("-------------------------------------------------------------------------\n");
    //--------Check that there are the correct number of arguments passed-----------------
    if(argc != 4) { 
        printf("usage: ./auto_corr chainfile no_params first_column \n");
        exit(1); // 0 means success typically, non-zero indicates an error
}

    //--------Extract arguments-----------------------------------------------------------
    sprintf(filename,"%s",argv[1]); // convert input file to string
    in_file = fopen(filename,"rb");  // open input file for reading

    no_params = atoi(argv[2]);      
    first_column = atoi(argv[3]);

    //--------What is the number of samples in chain file?--------------------------------
    N = 0; // Initialize count
    while(!feof(in_file)) {
        ch = fgetc(in_file);
        if(ch == '\n'){
            N++;
        }
    }
    printf("Number of samples: %li\n", N); // print number of samples
    if (N > MAX_SIZE) { // throw error if there are too many samples
        printf("ERROR - Too many samples! MAX_SIZE = %i", MAX_SIZE);
        exit(2);
    }

    //--------Generate a gsl matrix from the chains---------------------------------------
    printf("%i\n", no_params);
    chains = gsl_matrix_alloc(N, no_params); // allocate memory for gsl_matrix(rows, cols)
    // print the matrix (for testing)
    printf("Chain matrix \n");
    for (int m=0;m<N;m++) { //rows
        for (int n=0; n<no_params;n++) { // columns
            printf("%f  ",gsl_matrix_get(chains,m,n));
        }
        printf("\n");
    } 
    // gsl_matrix_fprintf(stdout,chains,"%f"); // easy way to print, no formatting though
    gsl_matrix_fscanf(in_file, chains);        // read in chains to the gsl_matrix
    fclose(in_file);

错误发生在 gsl_matrix_fscanf 行中，我看到的输出是

$ ./auto_corr auto_corr_test_data.dat 2 0
-------------------------------------------------------------------------
Number of samples: 15
2
Chain matrix
0.000000  0.000000
0.000000  0.000000
0.000000  0.000000
0.000000  0.000000
0.000000  0.000000
0.000000  0.000000
0.000000  0.000000
0.000000  0.000000
0.000000  0.000000
0.000000  0.000000
0.000000  0.000000
0.000000  0.000000
0.000000  0.000000
0.000000  0.000000
0.000000  0.000000
0.000000  0.000000
gsl: ./fprintf_source.c:165: ERROR: fscanf failed
Default GSL error handler invoked.
Abort trap: 6

Answer 1

在确定行数后，我忘记倒带输入文件。