Lines Matching refs:point

23 A **point** is a `PetscInt` that serves as an abstract "index" into arrays from iterable sets, such…
26 …(ndof, offset)`, where `ndof` is the number of values stored at that mesh point and `offset` is th…
27 So given the tuple for a mesh point, its data can be accessed by `array[offset + d]`, where `d` in …
38 …g the `(ndof, offset)` tuple for each mesh point generally first starts with setting the `ndof` fo…
39 …iates a set of degrees of freedom (dof), (a small space $\{e_k\}\ 0 < k < ndof$), with every point.
40 If `ndof` is not set for a mesh point, it is assumed to be 0.
42 The offset for each mesh point is usually set automatically by `PetscSectionSetUp()`.
43 This will concatenate each mesh point's dofs together in the order of the mesh points.
46 Alternatively, the offset for each mesh point can be set manually by `PetscSectionSetOffset()`, tho…
55 2. Specify the number of dofs per point with `PetscSectionSetDof()`. Any values not set will be zer…
61 For example, a dof attached to a cell point might represent pressure while dofs on vertices might r…
78 3. Set the number of dof for each point on each field with `PetscSectionSetFieldDof()`. Any values …
79 4. Set the **total** number of dof for each point with `PetscSectionSetDof()`. Thus value must be g…
80    `PetscSectionSetFieldDof()` at that point. Again, values not set will be zero.
85 … indexed by point in the outer dimension with a variable length inner dimension indexed by the dof…
89 In other words, will the array be laid out in a point-major or field-major fashion.
91 Point-major ordering corresponds to $v[\mathrm{pStart} <= point < \mathrm{pEnd}][0 <= field < \math…
92 All the dofs for each mesh point are stored contiguously, meaning the fields are **interlaced**.
93 Field-major ordering corresponds to $v[0 <= field < \mathrm{num\_fields}][\mathrm{pStart} <= point …
96 …0 to 2). Let the 0th field have `ndof=1` for each point and the 1st field have `ndof=2` for each p…
97 Denote each array entry $(p_i, f_i, d_i)$ for $p_i$ being the ith point, $f_i$ being the ith field,…
113 …ering is done with `PetscSectionSetPointMajor()`, where `PETSC_TRUE` sets point-major and `PETSC_F…
115 **NOTE:** The current default is for point-major, and many operations on `DMPlex` will only work wi…
133 PetscSectionGetOffset(PetscSection, PetscInt point, PetscInt &offset);
139 PetscSectionGetFieldOffset(PetscSection, PetscInt point, PetscInt field, PetscInt &offset);
157 For each shared mesh point, appoint one process to be the owner of that mesh point.
158 To describe this parallel mesh point layout, we use a `PetscSF` and call it the `pointSF`.
159 …s which processes "own" which mesh points and which process is the owner of each shared mesh point.
164 The global section returns $-(dof+1)$ for the number of dofs on an unowned (ghost) point, and tradi…
184 …of constrained dofs for a given point, and `PetscSectionSetConstraintIndices()` to indicate which …
196 …xample, the DoFs associated with grid point 0 appear directly before grid point 1, which appears b…
204 …l `PetscSectionPermute()` to generate a new `PetscSection` with the desired grid point permutation.
206 To just change the array layout without changing the grid point indexing, call `PetscSectionSetPerm…
207 …fore `PetscSectionSetUp()` and will only affect the calculation of the offsets for each grid point.
213 …e underlying data; it doesn't describe how DoFs attached to a single grid point are ordered or how…
223     point in the space, and just divide up points between processes.
224 …Conversely, `PetscSection` associates multiple unit vectors with every mesh point (one for each do…