**petsc-master 2020-11-28**

# PetscSection

Mapping from integers in a designated range to contiguous sets of integers.
### Synopsis

typedef struct _p_PetscSection *PetscSection;

In contrast to IS, which maps from integers to single integers, the range of a PetscSection is in the space of
contiguous sets of integers. These ranges are frequently interpreted as domains of other array-like objects,
especially other PetscSections, Vecs, and ISs. The domain is set with PetscSectionSetChart() and does not need to
start at 0. For each point in the domain of a PetscSection, the output set is represented through an offset and a
count, which are set using PetscSectionSetOffset() and PetscSectionSetDof() respectively. Lookup is typically using
accessors or routines like VecGetValuesSection().

### See Also

PetscSectionCreate(), PetscSectionDestroy(), PetscSectionSym

### Level

beginner

### Location

src/vec/is/section/../../../../include/petscsectiontypes.h
### Examples

src/dm/impls/stag/tutorials/ex1.c.html

src/ts/tutorials/ex11.c.html

### Implementations

_p_PetscSection in include/petsc/private/sectionimpl.h

Index of all PetscSection routines

Table of Contents for all manual pages

Index of all manual pages