1c4762a1bSJed Brown 2c4762a1bSJed Brown static char help[] = "Reads in a binary file, extracts a submatrix from it, and writes to another binary file.\n\ 3c4762a1bSJed Brown Options:\n\ 4c4762a1bSJed Brown -fin <mat> : input matrix file\n\ 5c4762a1bSJed Brown -fout <mat> : output marrix file\n\ 6c4762a1bSJed Brown -start <row> : the row from where the submat should be extracted\n\ 7c4762a1bSJed Brown -m <sx> : the size of the submatrix\n"; 8c4762a1bSJed Brown 9c4762a1bSJed Brown #include <petscmat.h> 10c4762a1bSJed Brown #include <petscvec.h> 11c4762a1bSJed Brown 12c4762a1bSJed Brown int main(int argc,char **args) 13c4762a1bSJed Brown { 14c4762a1bSJed Brown char fin[PETSC_MAX_PATH_LEN],fout[PETSC_MAX_PATH_LEN] ="default.mat"; 15c4762a1bSJed Brown PetscViewer fdin,fdout; 16c4762a1bSJed Brown Vec b; 17c4762a1bSJed Brown MatType mtype = MATSEQBAIJ; 18c4762a1bSJed Brown Mat A,*B; 19c4762a1bSJed Brown PetscInt start=0; 20c4762a1bSJed Brown PetscInt m; 21c4762a1bSJed Brown IS isrow,iscol; 22c4762a1bSJed Brown PetscBool flg; 23c4762a1bSJed Brown 24*9566063dSJacob Faibussowitsch PetscCall(PetscInitialize(&argc,&args,(char*)0,help)); 25*9566063dSJacob Faibussowitsch PetscCall(PetscOptionsGetString(NULL,NULL,"-fin",fin,sizeof(fin),&flg)); 2628b400f6SJacob Faibussowitsch PetscCheck(flg,PETSC_COMM_WORLD,PETSC_ERR_USER,"Must indicate binary file with the -fin option"); 27*9566063dSJacob Faibussowitsch PetscCall(PetscViewerBinaryOpen(PETSC_COMM_SELF,fin,FILE_MODE_READ,&fdin)); 28c4762a1bSJed Brown 29*9566063dSJacob Faibussowitsch PetscCall(PetscOptionsGetString(NULL,NULL,"-fout",fout,sizeof(fout),&flg)); 30*9566063dSJacob Faibussowitsch if (!flg) PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Writing submatrix to file : %s\n",fout)); 31*9566063dSJacob Faibussowitsch PetscCall(PetscViewerBinaryOpen(PETSC_COMM_SELF,fout,FILE_MODE_WRITE,&fdout)); 32c4762a1bSJed Brown 33*9566063dSJacob Faibussowitsch PetscCall(MatCreate(PETSC_COMM_SELF,&A)); 34*9566063dSJacob Faibussowitsch PetscCall(MatSetType(A,mtype)); 35*9566063dSJacob Faibussowitsch PetscCall(MatLoad(A,fdin)); 36*9566063dSJacob Faibussowitsch PetscCall(PetscViewerDestroy(&fdin)); 37c4762a1bSJed Brown 38*9566063dSJacob Faibussowitsch PetscCall(MatGetSize(A,&m,&m)); 39c4762a1bSJed Brown m /= 2; 40*9566063dSJacob Faibussowitsch PetscCall(PetscOptionsGetInt(NULL,NULL,"-start",&start,NULL)); 41*9566063dSJacob Faibussowitsch PetscCall(PetscOptionsGetInt(NULL,NULL,"-m",&m,NULL)); 42c4762a1bSJed Brown 43*9566063dSJacob Faibussowitsch PetscCall(ISCreateStride(PETSC_COMM_SELF,m,start,1,&isrow)); 44*9566063dSJacob Faibussowitsch PetscCall(ISCreateStride(PETSC_COMM_SELF,m,start,1,&iscol)); 45*9566063dSJacob Faibussowitsch PetscCall(MatCreateSubMatrices(A,1,&isrow,&iscol,MAT_INITIAL_MATRIX,&B)); 46*9566063dSJacob Faibussowitsch PetscCall(MatView(B[0],fdout)); 47c4762a1bSJed Brown 48*9566063dSJacob Faibussowitsch PetscCall(VecCreate(PETSC_COMM_SELF,&b)); 49*9566063dSJacob Faibussowitsch PetscCall(VecSetSizes(b,PETSC_DECIDE,m)); 50*9566063dSJacob Faibussowitsch PetscCall(VecSetFromOptions(b)); 51*9566063dSJacob Faibussowitsch PetscCall(MatView(B[0],fdout)); 52*9566063dSJacob Faibussowitsch PetscCall(PetscViewerDestroy(&fdout)); 53c4762a1bSJed Brown 54*9566063dSJacob Faibussowitsch PetscCall(MatDestroy(&A)); 55*9566063dSJacob Faibussowitsch PetscCall(MatDestroy(&B[0])); 56*9566063dSJacob Faibussowitsch PetscCall(VecDestroy(&b)); 57*9566063dSJacob Faibussowitsch PetscCall(PetscFree(B)); 58*9566063dSJacob Faibussowitsch PetscCall(ISDestroy(&iscol)); 59*9566063dSJacob Faibussowitsch PetscCall(ISDestroy(&isrow)); 60*9566063dSJacob Faibussowitsch PetscCall(PetscFinalize()); 61b122ec5aSJacob Faibussowitsch return 0; 62c4762a1bSJed Brown } 63c4762a1bSJed Brown 64c4762a1bSJed Brown /*TEST 65c4762a1bSJed Brown 66c4762a1bSJed Brown test: 67c4762a1bSJed Brown args: -fin ${DATAFILESPATH}/matrices/small -fout joe -start 2 -m 4 68dfd57a17SPierre Jolivet requires: datafilespath double !complex !defined(PETSC_USE_64BIT_INDICES) 69c4762a1bSJed Brown 70c4762a1bSJed Brown TEST*/ 71