1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
<center><a href="https://gitlab.com/petsc/petsc/-/blob/9fe822445bcdd45fb93170ff68fa7403d3f52f09/include/petscsectiontypes.h">Actual source code: petscsectiontypes.h</a></center><br>
<html>
<head>
<title></title>
<meta name="generator" content="c2html 0.9.6">
<meta name="date" content="2025-03-28T21:10:41+00:00">
</head>
<body bgcolor="#FFFFFF">
<pre width=80>
<a name="line1"> 1: </a><font color="#A020F0">#pragma once</font>
<a name="line3"> 3: </a><font color="#B22222">/* SUBMANSEC = <a href="../manualpages/PetscSection/PetscSection.html">PetscSection</a> */</font>
<a name="line5"> 5: </a><font color="#B22222">/*S</font>
<a name="line6"> 6: </a><font color="#B22222"> <a href="../manualpages/PetscSection/PetscSection.html">PetscSection</a> - Mapping from integers in a designated range to contiguous sets of integers.</font>
<a name="line8"> 8: </a><font color="#B22222"> The range of a `<a href="../manualpages/PetscSection/PetscSection.html">PetscSection</a>` is in the space of</font>
<a name="line9"> 9: </a><font color="#B22222"> contiguous sets of integers. These ranges are frequently interpreted as domains of other array-like objects,</font>
<a name="line10"> 10: </a><font color="#B22222"> especially other `<a href="../manualpages/PetscSection/PetscSection.html">PetscSection</a>`, `<a href="../manualpages/Vec/Vec.html">Vec</a>`s, and `<a href="../manualpages/IS/IS.html">IS</a>`s. The domain is set with `<a href="../manualpages/PetscSection/PetscSectionSetChart.html">PetscSectionSetChart</a>()` and does not need to</font>
<a name="line11"> 11: </a><font color="#B22222"> start at 0. For each point in the domain of a `<a href="../manualpages/PetscSection/PetscSection.html">PetscSection</a>`, the output set is represented through an offset and a</font>
<a name="line12"> 12: </a><font color="#B22222"> count, which are set using `<a href="../manualpages/PetscSection/PetscSectionSetOffset.html">PetscSectionSetOffset</a>()` and `<a href="../manualpages/PetscSection/PetscSectionSetDof.html">PetscSectionSetDof</a>()` respectively. Lookup is typically using</font>
<a name="line13"> 13: </a><font color="#B22222"> accessors or routines like `<a href="../manualpages/Vec/VecGetValuesSection.html">VecGetValuesSection</a>()`.</font>
<a name="line15"> 15: </a><font color="#B22222"> The `<a href="../manualpages/PetscSection/PetscSection.html">PetscSection</a>` object and methods are intended to be used in the PETSc `<a href="../manualpages/Vec/Vec.html">Vec</a>` and `<a href="../manualpages/Mat/Mat.html">Mat</a>` implementations. The indices returned by the `<a href="../manualpages/PetscSection/PetscSection.html">PetscSection</a>`</font>
<a name="line16"> 16: </a><font color="#B22222"> are appropriate for the kind of `<a href="../manualpages/Vec/Vec.html">Vec</a>` it is associated with. For example, if the vector being indexed is a local vector, we call the section a</font>
<a name="line17"> 17: </a><font color="#B22222"> local section. If the section indexes a global vector, we call it a global section. For parallel vectors, like global vectors, we use negative</font>
<a name="line18"> 18: </a><font color="#B22222"> indices to indicate dofs owned by other processes.</font>
<a name="line20"> 20: </a><font color="#B22222"> Level: beginner</font>
<a name="line22"> 22: </a><font color="#B22222">.seealso: [<a href="../manualpages/PetscSection/PetscSection.html">PetscSection</a>](ch_petscsection), `<a href="../manualpages/PetscSection/PetscSectionCreate.html">PetscSectionCreate</a>()`, `<a href="../manualpages/PetscSection/PetscSectionDestroy.html">PetscSectionDestroy</a>()`, `<a href="../manualpages/PetscSection/PetscSectionSym.html">PetscSectionSym</a>`</font>
<a name="line23"> 23: </a><font color="#B22222">S*/</font>
<a name="line24"> 24: </a><font color="#4169E1">typedef struct _p_PetscSection *<a href="../manualpages/PetscSection/PetscSection.html">PetscSection</a>;</font>
<a name="line26"> 26: </a><font color="#B22222">/*S</font>
<a name="line27"> 27: </a><font color="#B22222"> <a href="../manualpages/PetscSection/PetscSectionSym.html">PetscSectionSym</a> - Symmetries of the data referenced by a `<a href="../manualpages/PetscSection/PetscSection.html">PetscSection</a>`.</font>
<a name="line29"> 29: </a><font color="#B22222"> Often the order of data index by a `<a href="../manualpages/PetscSection/PetscSection.html">PetscSection</a>` is meaningful, and describes additional structure, such as points on a</font>
<a name="line30"> 30: </a><font color="#B22222"> line, grid, or lattice. If the data is accessed from a different "orientation", then the image of the data under</font>
<a name="line31"> 31: </a><font color="#B22222"> access then undergoes a symmetry transformation. A `<a href="../manualpages/PetscSection/PetscSectionSym.html">PetscSectionSym</a>` specifies these symmetries. The types of</font>
<a name="line32"> 32: </a><font color="#B22222"> symmetries that can be specified are of the form R * P, where R is a diagonal matrix of scalars, and P is a permutation.</font>
<a name="line34"> 34: </a><font color="#B22222"> Level: developer</font>
<a name="line36"> 36: </a><font color="#B22222">.seealso: [<a href="../manualpages/PetscSection/PetscSection.html">PetscSection</a>](ch_petscsection), `<a href="../manualpages/PetscSection/PetscSection.html">PetscSection</a>`, `<a href="../manualpages/PetscSection/PetscSectionSymCreate.html">PetscSectionSymCreate</a>()`, `<a href="../manualpages/PetscSection/PetscSectionSymDestroy.html">PetscSectionSymDestroy</a>()`, `<a href="../manualpages/PetscSection/PetscSectionSetSym.html">PetscSectionSetSym</a>()`, `<a href="../manualpages/PetscSection/PetscSectionGetSym.html">PetscSectionGetSym</a>()`, `<a href="../manualpages/PetscSection/PetscSectionSetFieldSym.html">PetscSectionSetFieldSym</a>()`,</font>
<a name="line37"> 37: </a><font color="#B22222"> `<a href="../manualpages/PetscSection/PetscSectionGetFieldSym.html">PetscSectionGetFieldSym</a>()`, `PetscSectionGetSymPoints()`, `<a href="../manualpages/PetscSection/PetscSectionSymType.html">PetscSectionSymType</a>`, `<a href="../manualpages/PetscSection/PetscSectionSymSetType.html">PetscSectionSymSetType</a>()`, `<a href="../manualpages/PetscSection/PetscSectionSymGetType.html">PetscSectionSymGetType</a>()`</font>
<a name="line38"> 38: </a><font color="#B22222">S*/</font>
<a name="line39"> 39: </a><font color="#4169E1">typedef struct _p_PetscSectionSym *<a href="../manualpages/PetscSection/PetscSectionSym.html">PetscSectionSym</a>;</font>
<a name="line41"> 41: </a><font color="#B22222">/*J</font>
<a name="line42"> 42: </a><font color="#B22222"> <a href="../manualpages/PetscSection/PetscSectionSymType.html">PetscSectionSymType</a> - String with the name of a `<a href="../manualpages/PetscSection/PetscSectionSym.html">PetscSectionSym</a>` type.</font>
<a name="line44"> 44: </a><font color="#B22222"> Level: developer</font>
<a name="line46"> 46: </a><font color="#B22222"> Note:</font>
<a name="line47"> 47: </a><font color="#B22222"> `<a href="../manualpages/PetscSection/PetscSectionSym.html">PetscSectionSym</a>` has no default implementation, but is used by `<a href="../manualpages/DM/DM.html">DM</a>` in `<a href="../manualpages/DMLabel/PetscSectionSymCreateLabel.html">PetscSectionSymCreateLabel</a>()`.</font>
<a name="line49"> 49: </a><font color="#B22222">.seealso: [<a href="../manualpages/PetscSection/PetscSection.html">PetscSection</a>](ch_petscsection), `<a href="../manualpages/PetscSection/PetscSectionSymSetType.html">PetscSectionSymSetType</a>()`, `<a href="../manualpages/PetscSection/PetscSectionSymGetType.html">PetscSectionSymGetType</a>()`, `<a href="../manualpages/PetscSection/PetscSectionSym.html">PetscSectionSym</a>`, `<a href="../manualpages/PetscSection/PetscSectionSymCreate.html">PetscSectionSymCreate</a>()`, `<a href="../manualpages/PetscSection/PetscSectionSymRegister.html">PetscSectionSymRegister</a>()`</font>
<a name="line50"> 50: </a><font color="#B22222">J*/</font>
<a name="line51"> 51: </a><font color="#4169E1">typedef const char *<a href="../manualpages/PetscSection/PetscSectionSymType.html">PetscSectionSymType</a>;</font>
</pre>
</body>
</html>
|
