带有 GSL 的稀疏矩阵 - 编译错误

Question

我正在测试 GNU Scientific Library (GSL)，我想用它创建一个稀疏矩阵。这是我的代码，直接来自https://www.gnu.org/software/gsl/manual/html_node/Sparse-Matrix-Examples.html:

#include <stdio.h>
#include <stdlib.h>

#include <gsl/gsl_spmatrix.h>

int
main()
{
    gsl_spmatrix *A = gsl_spmatrix_alloc(5, 4); /* triplet format */
    gsl_spmatrix *C;
    size_t i, j;

    /* build the sparse matrix */
    gsl_spmatrix_set(A, 0, 2, 3.1);
    gsl_spmatrix_set(A, 0, 3, 4.6);
    gsl_spmatrix_set(A, 1, 0, 1.0);
    gsl_spmatrix_set(A, 1, 2, 7.2);
    gsl_spmatrix_set(A, 3, 0, 2.1);
    gsl_spmatrix_set(A, 3, 1, 2.9);
    gsl_spmatrix_set(A, 3, 3, 8.5);
    gsl_spmatrix_set(A, 4, 0, 4.1);

    printf("printing all matrix elements:\n");
    for (i = 0; i < 5; ++i)
        for (j = 0; j < 4; ++j)
           printf("A(%zu,%zu) = %g\n", i, j,
           gsl_spmatrix_get(A, i, j));

    /* print out elements in triplet format */
    printf("matrix in triplet format (i,j,Aij):\n");
    for (i = 0; i < A->nz; ++i)
         printf("(%zu, %zu, %.1f)\n", A->i[i], A->p[i], A->data[i]);

    /* convert to compressed column format */
    C = gsl_spmatrix_compcol(A);

    printf("matrix in compressed column format:\n");
    printf("i = [ ");
    for (i = 0; i < C->nz; ++i)
        printf("%zu, ", C->i[i]);
    printf("]\n");

    printf("p = [ ");
    for (i = 0; i < C->size2 + 1; ++i)
         printf("%zu, ", C->p[i]);
    printf("]\n");

    printf("d = [ ");
    for (i = 0; i < C->nz; ++i)
         printf("%g, ", C->data[i]);
    printf("]\n");

    gsl_spmatrix_free(A);
    gsl_spmatrix_free(C);

    return 0;
}

我使用以下命令编译了这段代码：

 gcc test1.c -o test -lgsl -lgslcblas -lm

结果是：

 /tmp/ccyBfp0p.o: In function `main':
 test1.c:(.text+0x13): undefined reference to `gsl_spmatrix_alloc'
 test1.c:(.text+0x40): undefined reference to `gsl_spmatrix_set'
 test1.c:(.text+0x69): undefined reference to `gsl_spmatrix_set'
 test1.c:(.text+0x87): undefined reference to `gsl_spmatrix_set'
 test1.c:(.text+0xb0): undefined reference to `gsl_spmatrix_set'
 test1.c:(.text+0xd9): undefined reference to `gsl_spmatrix_set'
 /tmp/ccyBfp0p.o:test1.c:(.text+0x102): more undefined references to    `gsl_spmatrix_set' follow
 /tmp/ccyBfp0p.o: In function `main':
 test1.c:(.text+0x189): undefined reference to `gsl_spmatrix_get'
 test1.c:(.text+0x25d): undefined reference to `gsl_spmatrix_compcol'
 test1.c:(.text+0x39b): undefined reference to `gsl_spmatrix_free'
 test1.c:(.text+0x3a7): undefined reference to `gsl_spmatrix_free'
 collect2: error: ld returned 1 exit status

然后我尝试使用以下代码进行编译：

 gcc -I/usr/local/include/gsl -L/usr/local/lib -o test test1.c -lgsl -lgslcblas -lm

这编译代码没有错误，但是当我尝试运行它时出现以下错误：

 ./test: error while loading shared libraries: libgsl.so.19: cannot open shared object file: No such file or directory

但是当我这样做时：

 ls /usr/local/lib

我可以看到结果：

 libemon.a       libgslcblas.so        libgsl.so         python2.7
 libgsl.a        libgslcblas.so.0      libgsl.so.19      python3.4
 libgslcblas.a   libgslcblas.so.0.0.0  libgsl.so.19.1.0  site_ruby
 libgslcblas.la  libgsl.la             pkgconfig

我认为我的 GSL 安装有问题。但问题是，所有其他计算都可以正常工作！只有稀疏矩阵给了我这个问题。

Answer 1

如下更新$LD_LIBRARY_PATH 是否修复error while loading shared libraries？

export LD_LIBRARY_PATH=/usr/local/lib:$LD_LIBRARY_PATH