147c6ae99SBarry Smith #define PETSCDM_DLL 247c6ae99SBarry Smith 347c6ae99SBarry Smith /* 447c6ae99SBarry Smith Code for manipulating distributed regular arrays in parallel. 547c6ae99SBarry Smith */ 647c6ae99SBarry Smith 7e1589f56SBarry Smith #include "private/daimpl.h" /*I "petscdm.h" I*/ 847c6ae99SBarry Smith 947c6ae99SBarry Smith #undef __FUNCT__ 10aa219208SBarry Smith #define __FUNCT__ "DMDAGetGhostCorners" 1147c6ae99SBarry Smith /*@ 12aa219208SBarry Smith DMDAGetGhostCorners - Returns the global (x,y,z) indices of the lower left 1347c6ae99SBarry Smith corner of the local region, including ghost points. 1447c6ae99SBarry Smith 1547c6ae99SBarry Smith Not Collective 1647c6ae99SBarry Smith 1747c6ae99SBarry Smith Input Parameter: 1847c6ae99SBarry Smith . da - the distributed array 1947c6ae99SBarry Smith 2047c6ae99SBarry Smith Output Parameters: 2147c6ae99SBarry Smith + x,y,z - the corner indices (where y and z are optional; these are used 2247c6ae99SBarry Smith for 2D and 3D problems) 2347c6ae99SBarry Smith - m,n,p - widths in the corresponding directions (where n and p are optional; 2447c6ae99SBarry Smith these are used for 2D and 3D problems) 2547c6ae99SBarry Smith 2647c6ae99SBarry Smith Level: beginner 2747c6ae99SBarry Smith 2847c6ae99SBarry Smith Note: 2947c6ae99SBarry Smith The corner information is independent of the number of degrees of 30aa219208SBarry Smith freedom per node set with the DMDACreateXX() routine. Thus the x, y, z, and 3147c6ae99SBarry Smith m, n, p can be thought of as coordinates on a logical grid, where each 3247c6ae99SBarry Smith grid point has (potentially) several degrees of freedom. 3347c6ae99SBarry Smith Any of y, z, n, and p can be passed in as PETSC_NULL if not needed. 3447c6ae99SBarry Smith 3547c6ae99SBarry Smith .keywords: distributed array, get, ghost, corners, nodes, local indices 3647c6ae99SBarry Smith 37aa219208SBarry Smith .seealso: DMDAGetCorners(), DMDACreate1d(), DMDACreate2d(), DMDACreate3d(), DMDAGetOwnershipRanges() 3847c6ae99SBarry Smith 3947c6ae99SBarry Smith @*/ 40*7087cfbeSBarry Smith PetscErrorCode DMDAGetGhostCorners(DM da,PetscInt *x,PetscInt *y,PetscInt *z,PetscInt *m,PetscInt *n,PetscInt *p) 4147c6ae99SBarry Smith { 4247c6ae99SBarry Smith PetscInt w; 4347c6ae99SBarry Smith DM_DA *dd = (DM_DA*)da->data; 4447c6ae99SBarry Smith 4547c6ae99SBarry Smith PetscFunctionBegin; 4647c6ae99SBarry Smith PetscValidHeaderSpecific(da,DM_CLASSID,1); 4747c6ae99SBarry Smith /* since the xs, xe ... have all been multiplied by the number of degrees 4847c6ae99SBarry Smith of freedom per cell, w = dd->w, we divide that out before returning.*/ 4947c6ae99SBarry Smith w = dd->w; 5047c6ae99SBarry Smith if (x) *x = dd->Xs/w; if (m) *m = (dd->Xe - dd->Xs)/w; 5147c6ae99SBarry Smith if (y) *y = dd->Ys; if (n) *n = (dd->Ye - dd->Ys); 5247c6ae99SBarry Smith if (z) *z = dd->Zs; if (p) *p = (dd->Ze - dd->Zs); 5347c6ae99SBarry Smith PetscFunctionReturn(0); 5447c6ae99SBarry Smith } 5547c6ae99SBarry Smith 56