1 #ifndef lint 2 static char vcid[] = "$Id: axpy.c,v 1.14 1996/03/04 05:16:31 bsmith Exp bsmith $"; 3 #endif 4 5 #include "matimpl.h" /*I "mat.h" I*/ 6 7 /*@ 8 MatAXPY - Computes Y = a*X + Y 9 10 Input Parameters: 11 . X,Y - the matrices 12 . a - the scalar multiplier 13 14 .keywords: matrix, add 15 @*/ 16 int MatAXPY(Scalar *a,Mat X,Mat Y) 17 { 18 int m1,m2,n1,n2,i,*row,start,end,j,ncols,ierr; 19 Scalar *val,*vals; 20 21 PetscValidHeaderSpecific(X,MAT_COOKIE); PetscValidHeaderSpecific(Y,MAT_COOKIE); 22 MatGetSize(X,&m1,&n1); MatGetSize(X,&m2,&n2); 23 if (m1 != m2 || n1 != n2) SETERRQ(1,"MatAXPY:Non conforming matrix add"); 24 25 if (X->ops.axpy) { 26 ierr = (*X->ops.axpy)(a,X,Y); CHKERRQ(ierr); 27 } 28 else { 29 vals = (Scalar *) PetscMalloc( n1*sizeof(Scalar) ); CHKPTRQ(vals); 30 MatGetOwnershipRange(X,&start,&end); 31 for ( i=start; i<end; i++ ) { 32 MatGetRow(X,i,&ncols,&row,&val); 33 for ( j=0; j<ncols; j++ ) { 34 vals[j] = (*a)*val[j]; 35 } 36 ierr = MatSetValues(Y,1,&i,ncols,row,vals,ADD_VALUES); CHKERRQ(ierr); 37 MatRestoreRow(X,i,&ncols,&row,&val); 38 } 39 PetscFree(vals); 40 ierr = MatAssemblyBegin(Y,FINAL_ASSEMBLY); CHKERRQ(ierr); 41 ierr = MatAssemblyEnd(Y,FINAL_ASSEMBLY); CHKERRQ(ierr); 42 } 43 return 0; 44 } 45 46 /*@ 47 MatShift - Computes Y = Y + a I 48 49 Input Parameters: 50 . Y - the matrices 51 . a - the scalar 52 53 .seealso: MatDiagonalShift() 54 55 .keywords: matrix, add, shift 56 @*/ 57 int MatShift(Scalar *a,Mat Y) 58 { 59 int i,start,end,ierr; 60 61 PetscValidHeaderSpecific(Y,MAT_COOKIE); 62 if (Y->ops.shift) { 63 ierr = (*Y->ops.shift)(a,Y); CHKERRQ(ierr); 64 } 65 else { 66 MatGetOwnershipRange(Y,&start,&end); 67 for ( i=start; i<end; i++ ) { 68 ierr = MatSetValues(Y,1,&i,1,&i,a,ADD_VALUES); CHKERRQ(ierr); 69 } 70 ierr = MatAssemblyBegin(Y,FINAL_ASSEMBLY); CHKERRQ(ierr); 71 ierr = MatAssemblyEnd(Y,FINAL_ASSEMBLY); CHKERRQ(ierr); 72 } 73 return 0; 74 } 75 76 /*@ 77 MatDiagonalShift - Computes Y = Y + D. Where D is a diagonal matrix 78 represented as a vector. 79 80 Input Parameters: 81 . Y - the matrices 82 . D - the diagonal matrix, represented as a vector 83 84 .seealso: MatDiagonalShift() 85 86 .keywords: matrix, add, shift 87 @*/ 88 int MatDiagonalShift(Mat Y,Vec D) 89 { 90 int i,start,end,ierr; 91 92 PetscValidHeaderSpecific(Y,MAT_COOKIE); 93 if (Y->ops.shift) { 94 ierr = (*Y->ops.diagonalshift)(D,Y); CHKERRQ(ierr); 95 } 96 else { 97 int vstart,vend; 98 Scalar *v; 99 ierr = VecGetOwnershipRange(D,&vstart,&vend); CHKERRQ(ierr); 100 ierr = MatGetOwnershipRange(Y,&start,&end); CHKERRQ(ierr); 101 if (vstart != start || vend != end) 102 SETERRQ(1,"MatDiagonalShift:Vector shift not compatible with matrix"); 103 104 ierr = VecGetArray(D,&v); CHKERRQ(ierr); 105 for ( i=start; i<end; i++ ) { 106 ierr = MatSetValues(Y,1,&i,1,&i,v+i-start,ADD_VALUES); CHKERRQ(ierr); 107 } 108 ierr = MatAssemblyBegin(Y,FINAL_ASSEMBLY); CHKERRQ(ierr); 109 ierr = MatAssemblyEnd(Y,FINAL_ASSEMBLY); CHKERRQ(ierr); 110 } 111 return 0; 112 } 113