LAPACKE / GNU C ++:LAPACKE_zheevx()函数中的奇怪错误

时间:2016-06-21 00:41:13

标签: c++ g++ codeblocks lapack lapacke

这里是我在使用LAPACKE函数LAPACKE_zheevx()时遇到的奇怪错误的描述。计算四个特征值/向量中的三个的简单测试代码(来自英特尔网站的示例)运行良好并提供正确的输出。但是,如果我在源代码中引入任何字符串的声明(例如std :: string OutputFIlename;),编译进展顺利但在执行时我得到分段错误SIGSEGV !!!

首先,我将列出有效的代码:

//===========================
#include <iostream>
#include <string>
#include <fstream>  
#include <cassert>  

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

#include "Headers_LAPACKE\lapacke.h"
#include "Headers_LAPACKE\lapacke_config.h"
#include "Headers_LAPACKE\lapacke_mangling.h"
#include "Headers_LAPACKE\lapacke_utils.h"

void print_matrix( char* desc, lapack_int m, lapack_int n, lapack_complex_double* a, lapack_int lda );

int main()
{
    std::cout << "Start..." << std::endl;
    //std::string fn_VALS; 

    // --------------- LAPACKE --- define variables ----------------------------------------------------------------
    //

    // Define arguments for LAPACKE_zheevx() routine:
    int matrix_layout;  // = LAPACK_ROW_MAJOR or LAPACK_COL_MAJOR

    char jobz;          // It is ="V" to calculate EigenVECTORS and
                        // ="N" if you don't do it.

    char range;         // ="A" for ALL values (don't want this),
                        // ="V" for values in in the half-open interval (vl,vu],
                        // ="I" for EigenVALUES indexed from il through iu (this is what you want).

    char uplo;          // ="U" for Upper Triangle of the matrix, or
                        // ="L" for the Lower triangle of the matrix.

    lapack_int n;       // the order of matrix "a" to be diagonalized.

    lapack_complex_double* a;   // complex array of dimension (lda,n).
                                // On entry it is Hermitian matrix "a".
                                // uplo="U" means the leading n-by-n upper triangular part of "a" contain the upper triangular part of the Hermitial matrix to be diagonalized.
                                // uplo="L" means equivalent for the lower triangular part.
                                // On exit, this content is destroyed.

    lapack_int lda;     // leading dimension of "a": lda >= max(1,n).

    double    vl;         // taken into account only if range="V": vl<vu. Not referenced if range="I" or range="A".
    double    vu;         // taken into account only if range="V": vl<vu. Not referenced if range="I" or range="A".

    lapack_int il;      // taken into account only if range="I": il<iu. Indices in ascending order of SMALLEST EigenVALUE to be returned. Not referenced if range="v" or range="A".
    lapack_int iu;      // taken into account only if range="I": il<iu. Indices in ascending order of LARGEST EigenVALUE to be returned.  Not referenced if range="v" or range="A".

    double    abstol;     // The absolute error tolerance for EigenVALUES. If abstop =<0, then EPS*|T| is used. If you get info>0 (some eigenvalues did not converge) then try abstol=2*DLAMCH('S').
    lapack_int* m;      // total number of EigenVALUES found: 0 =< m =< n, If range="A" then m=n, if range="I" then m = iu-il+1.
    double* w;          // double precision array of dimension n. On normal exit, the first m elements contain the selected EigenVALUES in ASCENDING ORDER.
    lapack_complex_double* z; // double precision array of dimension (ldz, max(1,m)). If jobz="V" and info=0, the first m-columns of z contain normalized EigenVECTORS of a, corresponding to the selected EigenVALUES, with i-th column of z contains the Eigenvectro corresponding to w(i) eigenvalue.
    lapack_int ldz;     // leading dimension of array z. ldz>=1 and if jobz="V" then ldz >= max(1,n).

        // following are  used only with LAPACKE_zheevx_work() routine:.
        //lapack_complex_double* work;    // array of dimension max(1,lwork).
        //lapack_int lwork;               // lwork=-1 means workspace query. Othewise it has to be length of the array work: lwork=2*n for n>1, and lwork >=1 for N=<1.
        //double* rwork;                  // array dimension is 7*n;
        //lapack_int* iwork;              // array dimension is 5*n;

    lapack_int* ifail;  // jobz="V" and info=0: first m elemens of ifail are zero. jobz="V" and info>0: ifail contain indices of the eigenvectors that failed to converge.
    lapack_int info;    //info=0 means successful exit. info>0 means eigenvectors failed to converge, their indices are in ifail. info<0, info=-i means i-th argument had an illegal value.
    //
    // ------------------------------------------------------------------------------------------------------------

    matrix_layout = LAPACK_ROW_MAJOR;
    jobz = 'V'; vl = 0.0; vu =100.0;
    il = 1; iu=4; // are ignored now.
    range = 'V';
    uplo ='U';
    n = 4;
    lda = n;
    ldz = n;

    z = new lapack_complex_double [ldz*n];
    w = new double [n];
    a = new lapack_complex_double [lda*n];
    a[0] =lapack_complex_double{6.51,0.0}; a[1] =lapack_make_complex_double(-5.92, 9.53); a[2]=lapack_complex_double{-2.46,2.91}; a[3]=lapack_complex_double{8.84,3.21};
    a[4] =lapack_complex_double{0.0,0.0};  a[5] =lapack_make_complex_double(-1.73,0.0);   a[6]=lapack_complex_double{6.5,2.09};    a[7]=lapack_complex_double{1.32, 8.81};
    a[8] =lapack_complex_double{0.0,0.0};  a[9] =lapack_make_complex_double(0.0,0.0);     a[10]=lapack_complex_double{6.90,0.0};   a[11]=lapack_complex_double{-0.59,2.47};
    a[12]=lapack_complex_double{0.0,0.0};  a[13]=lapack_make_complex_double(0.0,0.0);     a[14]=lapack_complex_double{0.0,0.0};    a[15]=lapack_complex_double{-2.85,0.0};

    ifail = new lapack_int [n];
    abstol = -1;  // set default tolerance for calcuation of EigVals in the assigned interval.

    print_matrix( "Entry Matrix A:", n, n, a, lda );
    std::cout << std::endl;

    info = LAPACKE_zheevx(matrix_layout, jobz, range, uplo, n, a, lda,  vl,  vu,  il, iu,  abstol, m, w, z, ldz, ifail);

    if (info>0)
    {
        std::cout << "Error: ZHEEVX failed to compute eigenvalues/vectors.";
        exit(1);
    }
    std::cout << "info = " << info << std::endl;

    std::cout << "Number of eigvals found: " << *m << std::endl;
    for (int i_e =0; i_e<*m; i_e++)
    {
         std::cout << "Eigval. " << i_e << " is " << w[i_e] << std::endl;
    }

    print_matrix( "Selected EigVECTORS (column-wise):", n, n, z, ldz );
    std::cout << std::endl;


    std::cout << "Done :-) !!!" <<std::endl;

    return 0;
}


////////////////////////////////////////////////////////* Auxiliary routine: printing a matrix */
void print_matrix( char* desc, lapack_int m, lapack_int n, lapack_complex_double* a, lapack_int lda )
{
        lapack_int i, j;
        printf( "\n %s\n", desc );
        for( i = 0; i < m; i++ )
        {
            for( j = 0; j < n; j++ )
            {
                printf( " (%6.2f,%6.2f)", lapack_complex_double_real(a[i*lda+j]), lapack_complex_double_imag(a[i*lda+j]) );
            }
            printf( "\n" );
        }
}
//=======================================

现在,如果在main()中删除第2行的注释符号(//):// std :: string fn_VALS;这将成为std :: string fn_VALS;有了这个,源代码将编译,但它在运行时失败,出现分段错误SIGSEGV。

更多信息:

我使用的是Windows 7 Pro和Code :: Blocks,LAPACKE标题和dll是在2016年6月15日下载的。 从控制台:进程返回-1073741819(0xC0000005) 从Code :: Blocks

中的Call Stack窗口

.......... main()调用LAPACKE_zheevx()[lapacke.dll]

.......... LAPACKE_zheevx()调用LAPACKE_zheevx_work()[lapacke.dll]

.......... LAPACKE_zheevx_work()调用zheevx_()[lapack.dll]

请帮忙。

1 个答案:

答案 0 :(得分:1)

我尝试通过输入来编译您生成的程序:

g++ main.cpp -o main -llapacke -llapack -lblas -lm -Wall

标志-Wall启用所有警告。其中一个警告很有意思:

  

警告:'m'在此函数中未初始化使用[-Wuninitialized]

指针lapack_int* m;未初始化,因为LAPACKE_zheevx(..., m, ...);被调用。因此,它可以指向内存中的任何位置。期望指针m承载函数的输出参数,并且LAPACKE_zheevx()或后续函数可能取消引用指针m。它会导致未定义的行为:取决于m指向的位置,它可以保持不被注意,也可以触发分段错误。

您可以尝试lapack_int* m[1];代替lapack_int* m;吗?

This example from intel没有同样的问题,因为m被解除为MKL_INT并通过参数传递给函数(&m)。是你开始的吗?