LAPACKE矩阵求逆分段故障C

Question

我正在尝试使用 lapacke 库编写代码来反转 C 中的复杂矩阵。但是我遇到了一个分段错误，它似乎取决于矩阵的大小 N。更重要的是，每次编译程序或触摸任何东西时，发生分段错误的大小都会有所不同。这让我觉得代码在某个地方试图访问分配不当或被禁止的内存。不幸的是，我不明白这是怎么发生的，因为它似乎与 LAPACKE 函数主题本身有关。事实上，当函数 /*MatrixComplexInv(invA,A,N);*/ （其中调用 LAPACKE 函数进行反转）被注释时，分段错误不会发生。下面是可以编译的工作代码和运行自己的代码。

 #include <stdio.h>
#include <lapacke.h>
#include <complex.h>
#include <stdlib.h>
#include <math.h>

void  Ctranspose( double complex *, double complex * ,int );
void MatrixComplexInv(double complex *, double complex *, int );


int main(int argc,  const char * * argv) {


 int  i,j,k,N = 4;/*if N> bigger than a small number 4,6,7.. it gives segmentation fault*/

double complex *A = calloc(N*N,sizeof(double complex)),
               *b = calloc(N*N,sizeof(double complex)),
               *Ap =calloc(N*N,sizeof(double complex));


    double complex *invA =calloc(N*N,sizeof(double complex));


        for(i=0;i<N;i++){
            for(j=0;j<N;j++){ 

            A[i*N+j] = 1+sin(i*j)*i+I*j;    
            Ap[i*N+j] = 1+sin(i*j)*i+I*j;   
            }
          }

    /*Segmentation fault in this function, due to 
     * 
    LAPACKE_zgetrf(LAPACK_ROW_MAJOR, n, n, tempA , n,&n);


    LAPACKE_zgetri(LAPACK_ROW_MAJOR, n, tempA , n, &n );
    * 
    * both.
    */
    MatrixComplexInv(invA,A,N);


    for(i=0;i<N;i++){
     for(j=0;j<N;j++){ 
         for(k = 0;k<N;k++){
            b[i*N+j]+=invA[i*N + k]*Ap[k*N + j];
         }


   printf("(%lf,%lf)\t", creal(b[i*N + j]),cimag(b[i*N + j]));/*tests that the result produces the inverse matrix A^{-1}A = 1*/


    }
     printf("\n");
    }

      return 0;
    }   


    void Ctranspose( double complex *Transposed, double complex *M ,int n)
    {

    int i,j;
    for(i=0;i<n;i++)

    for(j=0;j<n;j++) Transposed[i+n*j] = M[i*n+j];
    }


    void MatrixComplexInv(double complex *invA, double complex *A, int n)
    {

    double complex *tempA = (double complex*) malloc( n*n*sizeof(double complex) );


     Ctranspose(tempA,A,n);

    /*SEGMENTATION HAPPEN IN THESE TWO FUNCTIONS*/
    LAPACKE_zgetrf(LAPACK_ROW_MAJOR, n, n, tempA , n,&n);


    LAPACKE_zgetri(LAPACK_ROW_MAJOR, n, tempA , n, &n );


     Ctranspose(invA,tempA,n);


     free(tempA);

    }

Answer 1

在 LAPACKE_zgetrf(LAPACK_ROW_MAJOR, n, n, tempA , n,&n); 中，LAPACKE_zgetrf points to n, a single integer. On the contrary, the argument ipiv should be a pointer to an array of integer of dimension max(m,n), to store pivot indices 的最后一个参数这可以解释分段错误。

LAPACKE_zgetrf() 计算的 ipiv 也必须作为输入提供给 LAPACKE_zgetri()，以获得正确的逆矩阵。

LAPACKE矩阵求逆分段故障C

LAPACKE matrix inversion segmentation fault C

c

segmentation-fault

lapack

lapacke