# MatLMVMIsAllocated
Returns a boolean flag that shows whether the necessary data structures for the underlying matrix is allocated. 
## Synopsis
```
#include "petscksp.h" 
PetscErrorCode MatLMVMIsAllocated(Mat B, PetscBool *flg)
```

## Input Parameters

- ***B -*** An LMVM-type matrix



## Output Parameter

- ***flg -*** `PETSC_TRUE` if allocated, `PETSC_FALSE` otherwise





## See Also
 [](chapter_ksp), [LMVM Matrices](sec_matlmvm), `MATLMVM`, `MatLMVMAllocate()`, `MatLMVMReset()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/utils/lmvm/lmvmutils.c.html#MatLMVMIsAllocated">src/ksp/ksp/utils/lmvm/lmvmutils.c</A>


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