# PetscDualSpaceGetInteriorData
Get all quadrature points necessary to compute the interior degrees of freedom from this space, as well as the matrix that computes the degrees of freedom from the quadrature values.  Degrees of freedom are interior degrees of freedom if they belong (by `PetscDualSpaceGetSection()`) to interior points in the reference `DMPLEX`: complementary boundary degrees of freedom are marked as constrained in the section returned by `PetscDualSpaceGetSection()`). 
## Synopsis
```
#include "petscfe.h" 
PetscErrorCode PetscDualSpaceGetInteriorData(PetscDualSpace sp, PetscQuadrature *intNodes, Mat *intMat)
```

## Input Parameter

- ***sp -*** The dualspace



## Output Parameters

- ***intNodes -*** A `PetscQuadrature` object containing all evaluation points needed to evaluate interior degrees of freedom
- ***intMat   -*** A matrix that computes dual space values from point values: size [spdim0 x (npoints * nc)], where spdim0 is
the size of the constrained layout (`PetscSectionGetConstrainStorageSize()`) of the dual space section,
npoints is the number of points in intNodes and nc is `PetscDualSpaceGetNumComponents()`.





## See Also
 `PetscDualSpace`, `PetscQuadrature`, `Mat`, `PetscDualSpaceCreate()`, `PetscDualSpaceGetDimension()`, `PetscDualSpaceGetNumComponents()`, `PetscQuadratureGetData()`

## Level
advanced

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/dt/dualspace/interface/dualspace.c.html#PetscDualSpaceGetInteriorData">src/dm/dt/dualspace/interface/dualspace.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/dt/dualspace/impls/lagrange/tutorials/ex1.c.html">src/dm/dt/dualspace/impls/lagrange/tutorials/ex1.c.html</A><BR>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/dm/dt/dualspace/interface/dualspace.c)


[Index of all DUALSPACE routines](index.md)  
[Table of Contents for all manual pages](/docs/manualpages/index.md)  
[Index of all manual pages](/docs/manualpages/singleindex.md)  
