slepc-3.22.2 2024-12-02

DSSort

Sorts the result of DSSolve() according to a given sorting criterion.

Synopsis

#include "slepcds.h" 
PetscErrorCode DSSort(DS ds,PetscScalar eigr[],PetscScalar eigi[],PetscScalar rr[],PetscScalar ri[],PetscInt *k)

Logically Collective

Input Parameters

	ds	- the direct solver context
	rr	- (optional) array containing auxiliary values (real part)
	ri	- (optional) array containing auxiliary values (imaginary part)

Input/Output Parameters

	eigr	- array containing the computed eigenvalues (real part)
	eigi	- array containing the computed eigenvalues (imaginary part)
	k	- (optional) number of elements in the leading group

Notes

This routine sorts the arrays provided in eigr and eigi, and also sorts the dense system stored inside ds (assumed to be in condensed form). The sorting criterion is specified with DSSetSlepcSC().

If arrays rr and ri are provided, then a (partial) reordering based on these values rather than on the eigenvalues is performed. In symmetric problems a total order is obtained (parameter k is ignored), but otherwise the result is sorted only partially. In this latter case, it is only guaranteed that all the first k elements satisfy the comparison with any of the last n-k elements. The output value of parameter k is the final number of elements in the first set.

Level

intermediate

Location

src/sys/classes/ds/interface/dsops.c

Index of all DS routines
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Index of all manual pages