Hi all,
I am using mkl pardiso to do Schur complement. So far I got it working for symmetric matrix. But for asymmetric matrix, I got crash at phase = 11. The error message is "... Access violation writing location ...."
Can anyone provide any guidance on what the possible root cause is? I am using mkl 2018 update 2. The source code is as below.
Thanks!
Hainan
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <mkl.h>
#include <iostream>
void main()
{
int n = 5;
double a[11] = { 2, 1.0,
1.0, 1.0,
6.0, 7.0,
2.5,
1.0, 1.0, 7.0, 3.5 };
int ia[6] = { 0, 2, 4, 6, 7, 11 };
int ja[11] = { 0, 4,
1, 4,
2, 4,
3,
0, 1, 2, 4 };
int matrix_order = LAPACK_ROW_MAJOR;
char uplo = 'U';
int mtype = 11; /* Real asymmetric matrix */
/* RHS and solution vectors. */
//double b[8], x[8];
int nrhs = 1; /* Number of right hand sides. */
/* Internal solver memory pointer pt, */
/* 32-bit: int pt[64]; 64-bit: long int pt[64] */
/* or void *pt[64] should be OK on both architectures */
void *pt[64];
/* Pardiso control parameters. */
int iparm[64];
int maxfct, mnum, phase, error, msglvl, info;
/* Auxiliary variables. */
int i, j;
double ddum; /* Double dummy */
int idum; /* Integer dummy. */
/* Schur data */
double schur[3] = { 0.0, 0.0,
0.0 };
int perm[5] = { 0, 0, 1, 1, 1 };
int ipiv[2];
int n_schur = 3; /* Schur complement solution size */
/* -------------------------------------------------------------------- */
/* .. Setup Pardiso control parameters. */
/* -------------------------------------------------------------------- */
for (i = 0; i < 64; i++)
{
iparm[i] = 0;
}
iparm[1 - 1] = 1; /* No solver default */
iparm[2 - 1] = 2; /* Fill-in reordering from METIS */
iparm[10 - 1] = 8; /* Perturb the pivot elements with 1E-13 */
iparm[11 - 1] = 0; /* Use nonsymmetric permutation and scaling MPS */
iparm[13 - 1] = 0; /* Maximum weighted matching algorithm is switched-off (default for symmetric). Try iparm[12] = 1 in case of inappropriate accuracy */
iparm[14 - 1] = 0; /* Output: Number of perturbed pivots */
iparm[18 - 1] = -1; /* Output: Number of nonzeros in the factor LU */
iparm[19 - 1] = -1; /* Output: Mflops for LU factorization */
iparm[35 - 1] = 1; /*0: one-base; 1: zero-base*/
iparm[36 - 1] = 1; /* Use Schur complement */
maxfct = 1; /* Maximum number of numerical factorizations. */
mnum = 1; /* Which factorization to use. */
msglvl = 1; /* Print statistical information in file */
error = 0; /* Initialize error flag */
/* -------------------------------------------------------------------- */
/* .. Initialize the internal solver memory pointer. This is only */
/* necessary for the FIRST call of the PARDISO solver. */
/* -------------------------------------------------------------------- */
for (i = 0; i < 64; i++)
{
pt[i] = 0;
}
/* -------------------------------------------------------------------- */
/* .. Reordering and Symbolic Factorization. This step also allocates */
/* all memory that is necessary for the factorization. */
/* -------------------------------------------------------------------- */
phase = 11;
pardiso(pt, &maxfct, &mnum, &mtype, &phase,
&n, a, ia, ja, perm, &nrhs, iparm, &msglvl, &ddum, &ddum, &error);
if (error != 0)
{
printf("\nERROR during symbolic factorization: %d", error);
exit(1);
}
}
