Hello all:
I'm trying to solve a linear system (9 by 9 full matrix) by pdgesv in c. I use the example code (http://icl.cs.utk.edu/lapack-forum/viewtopic.php?f=2&t=1683&sid=26b4f253...) and compiling is ok. However, there is a error info after calling pdgesv:
“On entry to PDGESV parameter number 602 had an illegal value”.
According to the PDGESV source code, it means the 2th element of the 6th argument was wrong, which means the descA[1] is wrong?
However, descA[1] (ictxt) is rewrited by Cblacs_gridinit(&ictxt, "Row", nprow, npcol).
after printf ictxt, I find all ictxt = 0. IS this reason lead to the error message?
I really need to solve a large dense(full) matrix, can someone help me or give me some advice?
The following is my C code:
PS: I've called MPI_Init(&argc,&argv) before entering Scalapack(int argc, char ** argv) and called MPI_Finalize() after leaving Scalapack(int argc, char ** argv).
#include <mpi.h>
#include <iostream>
#include <vector>
#include <cmath>
#include <cstdlib>
#include "Scalapack.h"
#include <mkl.h>
#include <mkl_scalapack.h>
#include "mkl_lapacke.h"
#include <mkl_cblas.h>
#define mat(matriz,coluna,i,j) (matriz[i*coluna+j])
#define p_of_i(i,bs,p) ( MKL_INT((i-1)/bs)%p)
#define l_of_i(i,bs,p) ( MKL_INT((i-1)/(p*bs)))
#define x_of_i(i,bs,p) (((i-1)%bs)+1)
#define numroc_ NUMROC
using namespace std;
extern "C"
{
/* BLACS C interface */
void Cblacs_pinfo(int* mypnum, int* nprocs);
void Cblacs_get( MKL_INT context, MKL_INT request, MKL_INT* value);
int Cblacs_gridinit( MKL_INT* context, char * order, MKL_INT np_row, MKL_INT np_col);
void Cblacs_gridinfo( MKL_INT context, MKL_INT* np_row, MKL_INT* np_col, MKL_INT* my_row,
MKL_INT* my_col);
int numroc_( MKL_INT *n, MKL_INT *nb, MKL_INT *iproc, MKL_INT *isrcproc, MKL_INT *nprocs);
void Cblacs_gridexit(MKL_INT ictxt);
void Cblacs_barrier(MKL_INT ictxt, char * order);
}
void find_nps(MKL_INT np, MKL_INT &nprow, MKL_INT & npcol);
int getIndex(MKL_INT row, MKL_INT col,MKL_INT NCOLS) {return row*NCOLS+col;}
CTEST_Scalapack::CTEST_Scalapack(void)
{
}
CTEST_Scalapack::~CTEST_Scalapack(void)
{
}
int CTEST_Scalapack::Scalapack(int argc, char ** argv)
{
int nprocs = 0;//MPI::COMM_WORLD.Get_size();
int rank = 0;//MPI::COMM_WORLD.Get_rank();
MPI_Comm_size(MPI_COMM_WORLD,&nprocs);
MPI_Comm_rank(MPI_COMM_WORLD,&rank);
std::cout<<"Returned: "<<"";
std::cout << "Hello World! I am "<< rank << " of "<< nprocs <<
std::endl;
srand(1);
MKL_INT myrow=0;
MKL_INT mycol=0;
MKL_INT ictxt=0;
MKL_INT nprow=0,npcol=0;
MKL_INT BLOCK_SIZE =2; //this gonna be tricky - should be 64, but cannot be larger than the original matrix
MKL_INT locR=0, locC=0;
MKL_INT block = BLOCK_SIZE;
MKL_INT izero = 0;
MKL_INT matrix_size = 9;
MKL_INT myone = 1;
MKL_INT nrhs = 1;
MKL_INT info=0;
int i=0,j=0;
double mone=(-1.e0),pone=(1.e0);
double AnormF=0.e0, XnormF=0.e0, RnormF=0.e0, BnormF=0.e0, residF=0.e0,eps=0.e0;
find_nps(nprocs,nprow,npcol);
Cblacs_pinfo( &rank, &nprocs ) ;
Cblacs_get(-1, 0, &ictxt);
Cblacs_gridinit(&ictxt, "Row", nprow, npcol);
Cblacs_gridinfo(ictxt, &nprow, &npcol, &myrow, &mycol);
locR = numroc_(&matrix_size, &block, &myrow, &izero, &nprow);
locC = numroc_(&matrix_size, &block, &mycol, &izero, &npcol);
////GLOBAL
double * A = new double[matrix_size*matrix_size]();
double * B = new double[matrix_size]();
double * Acpy = new double[matrix_size*matrix_size]();
double * Bcpy = new double[matrix_size]();
//LOCAL
double * local_know_vector = new double[locR]();
double * local_matrix = new double[locR*locC]();
MKL_INT* ipiv = new MKL_INT [locC*locR*block+1000000]();
B[2] = 1;
B[3] = 0;
B[4] = 0;
B[5] = 0;
A[0] = 19;
A[1] = 3;
A[2] = 1;
A[3] = 12;
A[4] = 1;
A[5] = 16;
A[6] = 1;
A[7] = 3;
A[8] = 11;
A[9] = -19;
A[10] = 3;
A[11] = 1;
A[12] = 12;
A[13] = 1;
A[14] = 16;
A[15] = 1;
A[16] = 3;
A[17] = 11;
A[18] = -19;
A[19] = -3;
A[20] = 1;
A[21] = 12;
A[22] = 1;
A[23] = 16;
A[24] = 1;
A[25] = 3;
A[26] = 11;
A[27] = -19;
A[28] = -3;
A[29] = -1;
A[30] = 12;
A[31] = 1;
A[32] = 16;
A[33] = 1;
A[34] = 3;
A[35] = 11;
A[36] = -19;
A[37] = -3;
A[38] = -1;
A[39] = -12;
A[40] = 1;
A[41] = 16;
A[42] = 1;
A[43] = 3;
A[44] = 11;
A[45] = -19;
A[46] = -3;
A[47] = -1;
A[48] = -12;
A[49] = -1;
A[50] = 16;
A[51] = 1;
A[52] = 3;
A[53] = 11;
A[54] = -19;
A[55] = -3;
A[56] = -1;
A[57] = -12;
A[58] = -1;
A[59] = -16;
A[60] = 1;
A[61] = 3;
A[62] = 11;
A[63] = -19;
A[64] = -3;
A[65] = -1;
A[66] = -12;
A[67] = -1;
A[68] = -16;
A[69] = -1;
A[70] = 3;
A[71] = 11;
A[72] = -19;
A[73] = -3;
A[74] = -1;
A[75] = -12;
A[76] = -1;
A[77] = -16;
A[78] = -1;
A[79] = -3;
A[80] = 11;
MKL_INT* descA = new MKL_INT[9]();
MKL_INT* descB = new MKL_INT[9]();
descA[0] = 1; // descriptor type
descA[1] = ictxt; // blacs context
descA[2] = matrix_size; // global number of rows
descA[3] = matrix_size; // global number of columns
descA[4] = block; // row block size
descA[5] = block; // column block size (DEFINED EQUAL THAN ROW BLOCK SIZE)
descA[6] = 0; // initial process row(DEFINED 0)
descA[7] = 0; // initial process column (DEFINED 0)
descA[8] = locR; // leading dimension of local array
descB[0] = 1; // descriptor type
descB[1] = ictxt; // blacs context
descB[2] = matrix_size; // global number of rows
descB[3] = 1; // global number of columns
descB[4] = block; // row block size
descB[5] = block; // column block size (DEFINED EQUAL THAN ROW BLOCK SIZE)
descB[6] = 0; // initial process row(DEFINED 0)
descB[7] = 0; // initial process column (DEFINED 0)
descB[8] = locR; // leading dimension of local array
int il=0, jl=0;
for(i=1; i< matrix_size+1; i++)
{
for(j=1; j< matrix_size+1; j++)
{
int pi = p_of_i(i,block,nprow);
int li = l_of_i(i,block,nprow);
int xi = x_of_i(i,block,nprow);
//printf("i = %d, j = %d, pi = %d, li = %d\n",i,j,pi,li);;fflush(stdout);
int pj = p_of_i(j,block,npcol);
int lj = l_of_i(j,block,npcol);
int xj = x_of_i(j,block,npcol);
//printf("i = %d, j = %d, pj = %d, lj = %d, xj = %d\n",i,j,pj,lj,xj);;fflush(stdout);
if( (pi == myrow) && (pj == mycol))
{
il = li*block+xi;
jl = lj*block+xj;
local_matrix[getIndex(il-1, jl-1, locC)] = A[getIndex(i-1,j-1,matrix_size)];
}
if( (pi == myrow) &&(mycol==0) )
{
local_know_vector[il-1] = B[i-1];
}
}
}
////STARTING PDGESV
pdgesv_(&matrix_size, &nrhs, local_matrix, &myone, &myone, descA, ipiv, local_know_vector, &myone, &myone, descB, &info);
if(rank==0)
{
if(info != 0) cout <<"PDGESV problem! Info "<<info<<endl;
}
for(i=0; i< locR; i++)
{
cout<<"**\n"<<"rank "<<rank<<" answer: "<<local_know_vector[i]<<endl;
}
if(NULL!=descA) {delete [] descA; descA=NULL;}
if(NULL!=descB) {delete [] descB; descB=NULL;}
if(NULL!=local_know_vector) {delete [] local_know_vector; local_know_vector=NULL;}
if(NULL!=local_matrix) {delete [] local_matrix; local_matrix=NULL;}
if(NULL!=Acpy) {delete [] Acpy; Acpy=NULL;}
if(NULL!=Bcpy) {delete [] Bcpy; Bcpy=NULL;}
if(NULL!=A) {delete [] A; A=NULL;}
if(NULL!=B) {delete [] B; B=NULL;}
Cblacs_gridexit(ictxt);
return 0;
}
void find_nps(MKL_INT np, MKL_INT &nprow, MKL_INT & npcol)
{
MKL_INT min_nprow=100000;
MKL_INT min_npcol=100000;
nprow = np;
npcol = np;
while(1) {
npcol--;
if(np%2==0 ) {
if(npcol ==1){
nprow --;
npcol = nprow;
}
}else {
if(npcol ==0){
nprow --;
npcol = nprow;
}
}
if(nprow*npcol == np) {
min_npcol = npcol;
if(nprow < min_nprow) min_nprow = nprow;
}
if(nprow ==1 ) break;
}
nprow = min_nprow;
npcol = min_npcol;
}
