10925cdddSBarry Smith #ifdef PETSC_RCS_HEADER 2*98a79cdbSBarry Smith static char vcid[] = "$Id: getcolv.c,v 1.3 1998/04/13 17:43:46 bsmith Exp bsmith $"; 30925cdddSBarry Smith #endif 40925cdddSBarry Smith 50925cdddSBarry Smith #include "src/mat/matimpl.h" /*I "mat.h" I*/ 60925cdddSBarry Smith 70925cdddSBarry Smith #undef __FUNC__ 882bf6240SBarry Smith #define __FUNC__ "MatGetColumnVector" 90925cdddSBarry Smith /*@ 1082bf6240SBarry Smith MatGetColumnVector - Gets the values from a given column of a matrix. 110925cdddSBarry Smith 12fee21e36SBarry Smith Collective on Mat and Vec 13fee21e36SBarry Smith 14*98a79cdbSBarry Smith Input Parameters: 15*98a79cdbSBarry Smith + X - the matrix 16*98a79cdbSBarry Smith . v - the vector 17*98a79cdbSBarry Smith - c - the column requested 18*98a79cdbSBarry Smith 1982bf6240SBarry Smith Contributed by: Denis Vanderstraeten 200925cdddSBarry Smith 2182bf6240SBarry Smith .keywords: matrix, column, get 220925cdddSBarry Smith 230925cdddSBarry Smith @*/ 2482bf6240SBarry Smith int MatGetColumnVector(Mat A, Vec yy, int col) 250925cdddSBarry Smith { 2682bf6240SBarry Smith Scalar *y,*v,zero = 0.0; 2782bf6240SBarry Smith int ierr,i,j,nz,*idx,M,N,Mv,Rs,Re,rs,re; 280925cdddSBarry Smith 290925cdddSBarry Smith PetscFunctionBegin; 3082bf6240SBarry Smith PetscValidHeaderSpecific(A,MAT_COOKIE); 3182bf6240SBarry Smith PetscValidHeaderSpecific(yy,VEC_COOKIE); 320925cdddSBarry Smith 3382bf6240SBarry Smith if (col < 0) SETERRQ(1,1,"Requested negative column"); 3482bf6240SBarry Smith ierr = MatGetSize(A,&M,&N); CHKERRQ(ierr); 3582bf6240SBarry Smith if (col >= N) SETERRQ(1,1,"Requested column larger than number columns in matrix"); 360925cdddSBarry Smith 3782bf6240SBarry Smith ierr = VecGetSize(yy,&Mv); CHKERRQ(ierr); 3882bf6240SBarry Smith if (M != Mv) SETERRQ(1,1,"Matrix does not have same number of columns as vector"); 3982bf6240SBarry Smith 4082bf6240SBarry Smith ierr = MatGetOwnershipRange(A,&Rs,&Re);CHKERRQ(ierr); 4182bf6240SBarry Smith ierr = VecGetOwnershipRange(yy,&rs,&re);CHKERRQ(ierr); 4282bf6240SBarry Smith if (Rs != rs || Re != re) SETERRQ(1,1,"Matrix does not have same ownership range as vector"); 4382bf6240SBarry Smith 4482bf6240SBarry Smith ierr = VecSet(&zero,yy);CHKERRQ(ierr); 4582bf6240SBarry Smith ierr = VecGetArray(yy,&y);CHKERRQ(ierr); 4682bf6240SBarry Smith 4782bf6240SBarry Smith for ( i=Rs; i<Re; i++ ) { 4882bf6240SBarry Smith ierr = MatGetRow(A,i,&nz,&idx,&v);CHKERRQ(ierr); 4982bf6240SBarry Smith if (nz && idx[0] <= col) { 5082bf6240SBarry Smith /* 5182bf6240SBarry Smith Should use faster search here 5282bf6240SBarry Smith */ 5382bf6240SBarry Smith for ( j=0; j<nz; j++ ) { 5482bf6240SBarry Smith if (idx[j] >= col) { 5582bf6240SBarry Smith if (idx[j] == col) y[i-rs] = v[j]; 5682bf6240SBarry Smith break; 570925cdddSBarry Smith } 580925cdddSBarry Smith } 590925cdddSBarry Smith } 6082bf6240SBarry Smith ierr = MatRestoreRow(A,i,&nz,&idx,&v);CHKERRQ(ierr); 610925cdddSBarry Smith } 620925cdddSBarry Smith 6382bf6240SBarry Smith ierr = VecRestoreArray(yy,&y);CHKERRQ(ierr); 640925cdddSBarry Smith PetscFunctionReturn(0); 650925cdddSBarry Smith } 66