MatStructure

Indicates if two matrices have the same nonzero structure

Synopsis

typedef enum {
  DIFFERENT_NONZERO_PATTERN,
  SUBSET_NONZERO_PATTERN,
  SAME_NONZERO_PATTERN,
  UNKNOWN_NONZERO_PATTERN
} MatStructure;

Values

• SAME_NONZERO_PATTERN - the two matrices have identical nonzero patterns

• DIFFERENT_NONZERO_PATTERN - the two matrices may have different nonzero patterns

• SUBSET_NONZERO_PATTERN - the nonzero pattern of the second matrix is a subset of the nonzero pattern of the first matrix

• UNKNOWN_NONZERO_PATTERN - there is no known relationship between the nonzero patterns. In this case the implementations may try to detect a relationship to optimize the operation

Note

Certain matrix operations (such as MatAXPY()) can run much faster if the sparsity pattern of the matrices are the same. But actually determining if the patterns are the same may be costly. This provides a way for users who know something about the sparsity patterns to provide this information to certain PETSc routines.

See Also

Matrices, Mat, MatCopy(), MatAXPY(), MatAYPX()

Level

beginner

Location

include/petscmat.h

Examples

src/ksp/ksp/tutorials/ex19.c
src/ksp/ksp/tutorials/ex79.c
src/mat/tutorials/ex9.c
src/tao/unconstrained/tutorials/spectraladjointassimilation.c
src/ksp/ksp/tutorials/ex34.c
src/tao/pde_constrained/tutorials/hyperbolic.c
src/tao/tutorials/ex4.c
src/ksp/ksp/tutorials/ex29.c

Examples

src/ksp/ksp/tutorials/ex76.c
src/ksp/pc/tutorials/ex4.c
src/tao/pde_constrained/tutorials/hyperbolic.c

Examples

src/ksp/ksp/tutorials/ex77.c
src/ts/tutorials/ex50.c
src/tao/pde_constrained/tutorials/parabolic.c
src/ksp/ksp/tutorials/ex76.c
src/tao/unconstrained/tutorials/burgers_spectral.c
src/tao/pde_constrained/tutorials/hyperbolic.c
src/ksp/ksp/tutorials/ex79.c
src/ksp/ksp/tutorials/ex21.c
src/tao/pde_constrained/tutorials/elliptic.c

Examples

src/ksp/ksp/tutorials/ex76.c

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