STSetMatStructure

Sets an internal MatStructure attribute to indicate which is the relation of the sparsity pattern of the two matrices A and B constituting the generalized eigenvalue problem. This function has no effect in the case of standard eigenproblems.

Synopsis

#include "slepcst.h" 
PetscErrorCode STSetMatStructure(ST st,MatStructure str)
Collective on ST

Input Parameters

st - the spectral transformation context
str - either SAME_NONZERO_PATTERN, DIFFERENT_NONZERO_PATTERN or SUBSET_NONZERO_PATTERN

Options Database Key

-st_matstructure <str> - Indicates the structure flag, where <str> is one of 'same' (A and B have the same nonzero pattern), 'different' (A and B have different nonzero pattern) or 'subset' (B's nonzero pattern is a subset of A's).

Note

By default, the sparsity patterns are assumed to be different. If the patterns are equal or a subset then it is recommended to set this attribute for efficiency reasons (in particular, for internal MatAXPY() operations).

See Also

STSetOperators(), MatAXPY()

Location: src/st/interface/stset.c
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