:orphan:
# MatCreate
Creates a matrix where the type is determined from either a call to `MatSetType()` or from the options database with a call to `MatSetFromOptions()`. The default matrix type is `MATAIJ`, using the routines `MatCreateSeqAIJ()` or `MatCreateAIJ()` if you do not set a type in the options database. If you never call `MatSetType()` or `MatSetFromOptions()` it will generate an error when you try to use the matrix. 
## Synopsis
```
#include "petscmat.h"  
PetscErrorCode MatCreate(MPI_Comm comm, Mat *A)
```
Collective


## Input Parameter

- ***comm -*** MPI communicator



## Output Parameter

- ***A -*** the matrix



## Options Database Keys

- ***-mat_type seqaij   -*** `MATSEQAIJ` type, uses `MatCreateSeqAIJ()`
- ***-mat_type mpiaij   -*** `MATMPIAIJ` type, uses `MatCreateAIJ()`
- ***-mat_type seqdense -*** `MATSEQDENSE`, uses `MatCreateSeqDense()`
- ***-mat_type mpidense -*** `MATMPIDENSE` type, uses `MatCreateDense()`
- ***-mat_type seqbaij  -*** `MATSEQBAIJ` type, uses `MatCreateSeqBAIJ()`
- ***-mat_type mpibaij  -*** `MATMPIBAIJ` type, uses `MatCreateBAIJ()`


See the manpages for particular formats (e.g., `MATSEQAIJ`)
for additional format-specific options.




## See Also
 [](ch_matrices), `Mat`, `MatCreateSeqAIJ()`, `MatCreateAIJ()`,
`MatCreateSeqDense()`, `MatCreateDense()`,
`MatCreateSeqBAIJ()`, `MatCreateBAIJ()`,
`MatCreateSeqSBAIJ()`, `MatCreateSBAIJ()`,
`MatConvert()`

## Level
beginner

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/utils/gcreate.c.html#MatCreate">src/mat/utils/gcreate.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/bench_kspsolve.c.html">src/ksp/ksp/tutorials/bench_kspsolve.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex1.c.html">src/ksp/ksp/tutorials/ex1.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex10.c.html">src/ksp/ksp/tutorials/ex10.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex100.c.html">src/ksp/ksp/tutorials/ex100.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex100f.F90.html">src/ksp/ksp/tutorials/ex100f.F90</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex11.c.html">src/ksp/ksp/tutorials/ex11.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex11f.F90.html">src/ksp/ksp/tutorials/ex11f.F90</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex12.c.html">src/ksp/ksp/tutorials/ex12.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex15.c.html">src/ksp/ksp/tutorials/ex15.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex15f.F90.html">src/ksp/ksp/tutorials/ex15f.F90</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex16.c.html">src/ksp/ksp/tutorials/ex16.c</A><BR>

## Implementations

<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/da/hypre/mhyp.c.html#MatCreate_HYPREStruct">MatCreate_HYPREStruct in src/dm/impls/da/hypre/mhyp.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/impls/da/hypre/mhyp.c.html#MatCreate_HYPRESStruct">MatCreate_HYPRESStruct in src/dm/impls/da/hypre/mhyp.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/adj/mpi/mpiadj.c.html#MatCreate_MPIAdj">MatCreate_MPIAdj in src/mat/impls/adj/mpi/mpiadj.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/mpi/aijmkl/mpiaijmkl.c.html#MatCreate_MPIAIJMKL">MatCreate_MPIAIJMKL in src/mat/impls/aij/mpi/aijmkl/mpiaijmkl.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/mpi/aijperm/mpiaijperm.c.html#MatCreate_MPIAIJPERM">MatCreate_MPIAIJPERM in src/mat/impls/aij/mpi/aijperm/mpiaijperm.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/mpi/aijsell/mpiaijsell.c.html#MatCreate_MPIAIJSELL">MatCreate_MPIAIJSELL in src/mat/impls/aij/mpi/aijsell/mpiaijsell.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/mpi/crl/mcrl.c.html#MatCreate_MPIAIJCRL">MatCreate_MPIAIJCRL in src/mat/impls/aij/mpi/crl/mcrl.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/mpi/kokkos/mpiaijkok.kokkos.cxx.html#MatCreate_MPIAIJKokkos">MatCreate_MPIAIJKokkos in src/mat/impls/aij/mpi/kokkos/mpiaijkok.kokkos.cxx</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/mpi/mpiaij.c.html#MatCreate_MPIAIJ">MatCreate_MPIAIJ in src/mat/impls/aij/mpi/mpiaij.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/mpi/mpicusparse/mpiaijcusparse.cu.html#MatCreate_MPIAIJCUSPARSE">MatCreate_MPIAIJCUSPARSE in src/mat/impls/aij/mpi/mpicusparse/mpiaijcusparse.cu</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/mpi/mpihipsparse/mpiaijhipsparse.hip.c.html#MatCreate_MPIAIJHIPSPARSE">MatCreate_MPIAIJHIPSPARSE in src/mat/impls/aij/mpi/mpihipsparse/mpiaijhipsparse.hip.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/mpi/mpiviennacl/mpiaijviennacl.cxx.html#MatCreate_MPIAIJViennaCL">MatCreate_MPIAIJViennaCL in src/mat/impls/aij/mpi/mpiviennacl/mpiaijviennacl.cxx</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/seq/aij.c.html#MatCreate_SeqAIJ">MatCreate_SeqAIJ in src/mat/impls/aij/seq/aij.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/seq/aijmkl/aijmkl.c.html#MatCreate_SeqAIJMKL">MatCreate_SeqAIJMKL in src/mat/impls/aij/seq/aijmkl/aijmkl.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/seq/aijperm/aijperm.c.html#MatCreate_SeqAIJPERM">MatCreate_SeqAIJPERM in src/mat/impls/aij/seq/aijperm/aijperm.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/seq/aijsell/aijsell.c.html#MatCreate_SeqAIJSELL">MatCreate_SeqAIJSELL in src/mat/impls/aij/seq/aijsell/aijsell.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/seq/crl/crl.c.html#MatCreate_SeqAIJCRL">MatCreate_SeqAIJCRL in src/mat/impls/aij/seq/crl/crl.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/seq/kokkos/aijkok.kokkos.cxx.html#MatCreate_SeqAIJKokkos">MatCreate_SeqAIJKokkos in src/mat/impls/aij/seq/kokkos/aijkok.kokkos.cxx</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/seq/seqcusparse/aijcusparse.cu.html#MatCreate_SeqAIJCUSPARSE">MatCreate_SeqAIJCUSPARSE in src/mat/impls/aij/seq/seqcusparse/aijcusparse.cu</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/seq/seqhipsparse/aijhipsparse.hip.c.html#MatCreate_SeqAIJHIPSPARSE">MatCreate_SeqAIJHIPSPARSE in src/mat/impls/aij/seq/seqhipsparse/aijhipsparse.hip.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/seq/seqviennacl/aijviennacl.cxx.html#MatCreate_SeqAIJViennaCL">MatCreate_SeqAIJViennaCL in src/mat/impls/aij/seq/seqviennacl/aijviennacl.cxx</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/baij/mpi/baijmkl/mpibaijmkl.c.html#MatCreate_MPIBAIJMKL">MatCreate_MPIBAIJMKL in src/mat/impls/baij/mpi/baijmkl/mpibaijmkl.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/baij/mpi/mpibaij.c.html#MatCreate_MPIBAIJ">MatCreate_MPIBAIJ in src/mat/impls/baij/mpi/mpibaij.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/baij/seq/baij.c.html#MatCreate_SeqBAIJ">MatCreate_SeqBAIJ in src/mat/impls/baij/seq/baij.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/baij/seq/baijmkl/baijmkl.c.html#MatCreate_SeqBAIJMKL">MatCreate_SeqBAIJMKL in src/mat/impls/baij/seq/baijmkl/baijmkl.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/blockmat/seq/blockmat.c.html#MatCreate_BlockMat">MatCreate_BlockMat in src/mat/impls/blockmat/seq/blockmat.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/cdiagonal/cdiagonal.c.html#MatCreate_ConstantDiagonal">MatCreate_ConstantDiagonal in src/mat/impls/cdiagonal/cdiagonal.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/composite/mcomposite.c.html#MatCreate_Composite">MatCreate_Composite in src/mat/impls/composite/mcomposite.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/dense/mpi/cupm/cuda/matmpidensecuda.cu.html#MatCreate_MPIDenseCUDA">MatCreate_MPIDenseCUDA in src/mat/impls/dense/mpi/cupm/cuda/matmpidensecuda.cu</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/dense/mpi/cupm/hip/matmpidensehip.hip.c.html#MatCreate_MPIDenseHIP">MatCreate_MPIDenseHIP in src/mat/impls/dense/mpi/cupm/hip/matmpidensehip.hip.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/dense/mpi/mpidense.c.html#MatCreate_MPIDense">MatCreate_MPIDense in src/mat/impls/dense/mpi/mpidense.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/dense/seq/cupm/cuda/matseqdensecuda.cu.html#MatCreate_SeqDenseCUDA">MatCreate_SeqDenseCUDA in src/mat/impls/dense/seq/cupm/cuda/matseqdensecuda.cu</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/dense/seq/cupm/hip/matseqdensehip.hip.c.html#MatCreate_SeqDenseHIP">MatCreate_SeqDenseHIP in src/mat/impls/dense/seq/cupm/hip/matseqdensehip.hip.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/dense/seq/dense.c.html#MatCreate_SeqDense">MatCreate_SeqDense in src/mat/impls/dense/seq/dense.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/dummy/matdummy.c.html#MatCreate_Dummy">MatCreate_Dummy in src/mat/impls/dummy/matdummy.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/elemental/matelem.cxx.html#MatCreate_Elemental">MatCreate_Elemental in src/mat/impls/elemental/matelem.cxx</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/fft/fftw/fftw.c.html#MatCreate_FFTW">MatCreate_FFTW in src/mat/impls/fft/fftw/fftw.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/h2opus/cuda/math2opus.cu.html#MatCreate_H2OPUS">MatCreate_H2OPUS in src/mat/impls/h2opus/cuda/math2opus.cu</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/htool/htool.cxx.html#MatCreate_Htool">MatCreate_Htool in src/mat/impls/htool/htool.cxx</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/hypre/mhypre.c.html#MatCreate_HYPRE">MatCreate_HYPRE in src/mat/impls/hypre/mhypre.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/is/matis.c.html#MatCreate_IS">MatCreate_IS in src/mat/impls/is/matis.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/kaij/kaij.c.html#MatCreate_KAIJ">MatCreate_KAIJ in src/mat/impls/kaij/kaij.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/maij/maij.c.html#MatCreate_MAIJ">MatCreate_MAIJ in src/mat/impls/maij/maij.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/mffd/mffd.c.html#MatCreate_MFFD">MatCreate_MFFD in src/mat/impls/mffd/mffd.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/nest/matnest.c.html#MatCreate_Nest">MatCreate_Nest in src/mat/impls/nest/matnest.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/preallocator/matpreallocator.c.html#MatCreate_Preallocator">MatCreate_Preallocator in src/mat/impls/preallocator/matpreallocator.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/sbaij/mpi/mpisbaij.c.html#MatCreate_MPISBAIJ">MatCreate_MPISBAIJ in src/mat/impls/sbaij/mpi/mpisbaij.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/sbaij/seq/sbaij.c.html#MatCreate_SeqSBAIJ">MatCreate_SeqSBAIJ in src/mat/impls/sbaij/seq/sbaij.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/scalapack/matscalapack.c.html#MatCreate_ScaLAPACK">MatCreate_ScaLAPACK in src/mat/impls/scalapack/matscalapack.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/scatter/mscatter.c.html#MatCreate_Scatter">MatCreate_Scatter in src/mat/impls/scatter/mscatter.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/sell/mpi/mpisell.c.html#MatCreate_MPISELL">MatCreate_MPISELL in src/mat/impls/sell/mpi/mpisell.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/sell/seq/sell.c.html#MatCreate_SeqSELL">MatCreate_SeqSELL in src/mat/impls/sell/seq/sell.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/shell/shell.c.html#MatCreate_Shell">MatCreate_Shell in src/mat/impls/shell/shell.c</A><BR>


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