1: /*
  2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  4:    Copyright (c) 2002-, Universitat Politecnica de Valencia, Spain

  6:    This file is part of SLEPc.
  7:    SLEPc is distributed under a 2-clause BSD license (see LICENSE).
  8:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  9: */
 10: /*
 11:    Sorting criterion for various solvers
 12: */

 14: #pragma once

 16: #include <slepcsys.h>
 17: #include <slepcrgtypes.h>

 19: /* SUBMANSEC = sys */

 21: /*S
 22:   SlepcEigenvalueComparisonFn - A prototype of an eigenvalue comparison function that would be passed to EPSSetEigenvalueComparison() and analogue functions in other solver types

 24:   Calling Sequence:
 25: +   ar     - real part of the 1st eigenvalue
 26: .   ai     - imaginary part of the 1st eigenvalue
 27: .   br     - real part of the 2nd eigenvalue
 28: .   bi     - imaginary part of the 2nd eigenvalue
 29: .   res    - [output] result of comparison
 30: -   ctx    - [optional] user-defined context for private data for the
 31:              eigenvalue comparison routine (may be NULL)

 33:   Level: advanced

 35: .seealso: EPSSetEigenvalueComparison()
 36: S*/
 37: PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(SlepcEigenvalueComparisonFn)(PetscScalar ar,PetscScalar ai,PetscScalar br,PetscScalar bi,PetscInt *res,void *ctx);

 39: /*S
 40:   SlepcArbitrarySelectionFn - A prototype of an arbitrary selection function that would be passed to EPSSetArbitrarySelection() and analogue functions in other solver types

 42:   Calling Sequence:
 43: +   er     - real part of the current eigenvalue approximation
 44: .   ei     - imaginary part of the current eigenvalue approximation
 45: .   xr     - real part of the current eigenvector approximation
 46: .   xi     - imaginary part of the current eigenvector approximation
 47: .   rr     - result of evaluation (real part)
 48: .   ri     - result of evaluation (imaginary part)
 49: -   ctx    - [optional] user-defined context for private data for the
 50:              arbitrary selection routine (may be NULL)

 52:   Level: advanced

 54: .seealso: EPSSetArbitrarySelection()
 55: S*/
 56: PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(SlepcArbitrarySelectionFn)(PetscScalar er,PetscScalar ei,Vec xr,Vec xi,PetscScalar *rr,PetscScalar *ri,void *ctx);

 58: /*S
 59:     SlepcSC - Data structure (C struct) for storing information about
 60:         the sorting criterion used by different eigensolver objects.

 62:    Notes:
 63:    The SlepcSC structure contains a mapping function and a comparison
 64:    function (with associated contexts).
 65:    The mapping function usually calls ST's backtransform.
 66:    An optional region can also be used to give higher priority to values inside it.

 68:    The comparison function must have the following calling sequence

 70: $  comparison(PetscScalar ar,PetscScalar ai,PetscScalar br,PetscScalar bi,PetscInt *res,void *ctx)

 72: +  ar  - real part of the 1st eigenvalue
 73: .  ai  - imaginary part of the 1st eigenvalue
 74: .  br  - real part of the 2nd eigenvalue
 75: .  bi  - imaginary part of the 2nd eigenvalue
 76: .  res - result of comparison
 77: -  ctx - optional context, stored in comparisonctx

 79:    The returning parameter 'res' can be
 80: +  negative - if the 1st value is preferred to the 2st one
 81: .  zero     - if both values are equally preferred
 82: -  positive - if the 2st value is preferred to the 1st one

 84:    Fortran usage is not supported.

 86:    Level: developer

 88: .seealso: SlepcSCCompare()
 89: S*/
 90: struct _n_SlepcSC {
 91:   /* map values before sorting, typically a call to STBackTransform (mapctx=ST) */
 92:   PetscErrorCode (*map)(PetscObject,PetscInt,PetscScalar*,PetscScalar*);
 93:   PetscObject    mapobj;
 94:   /* comparison function such as SlepcCompareLargestMagnitude */
 95:   SlepcEigenvalueComparisonFn *comparison;
 96:   void           *comparisonctx;
 97:   /* optional region for filtering */
 98:   RG             rg;
 99: };
100: typedef struct _n_SlepcSC* SlepcSC;

102: SLEPC_EXTERN PetscErrorCode SlepcSCCompare(SlepcSC,PetscScalar,PetscScalar,PetscScalar,PetscScalar,PetscInt*);
103: SLEPC_EXTERN PetscErrorCode SlepcSortEigenvalues(SlepcSC,PetscInt n,PetscScalar *eigr,PetscScalar *eigi,PetscInt *perm);

105: SLEPC_EXTERN PetscErrorCode SlepcMap_ST(PetscObject,PetscInt,PetscScalar*,PetscScalar*);

107: SLEPC_EXTERN PetscErrorCode SlepcCompareLargestMagnitude(PetscScalar,PetscScalar,PetscScalar,PetscScalar,PetscInt*,void*);
108: SLEPC_EXTERN PetscErrorCode SlepcCompareSmallestMagnitude(PetscScalar,PetscScalar,PetscScalar,PetscScalar,PetscInt*,void*);
109: SLEPC_EXTERN PetscErrorCode SlepcCompareLargestReal(PetscScalar,PetscScalar,PetscScalar,PetscScalar,PetscInt*,void*);
110: SLEPC_EXTERN PetscErrorCode SlepcCompareSmallestReal(PetscScalar,PetscScalar,PetscScalar,PetscScalar,PetscInt*,void*);
111: SLEPC_EXTERN PetscErrorCode SlepcCompareLargestImaginary(PetscScalar,PetscScalar,PetscScalar,PetscScalar,PetscInt*,void*);
112: SLEPC_EXTERN PetscErrorCode SlepcCompareSmallestImaginary(PetscScalar,PetscScalar,PetscScalar,PetscScalar,PetscInt*,void*);
113: SLEPC_EXTERN PetscErrorCode SlepcCompareTargetMagnitude(PetscScalar,PetscScalar,PetscScalar,PetscScalar,PetscInt*,void*);
114: SLEPC_EXTERN PetscErrorCode SlepcCompareTargetReal(PetscScalar,PetscScalar,PetscScalar,PetscScalar,PetscInt*,void*);
115: #if defined(PETSC_USE_COMPLEX)
116: SLEPC_EXTERN PetscErrorCode SlepcCompareTargetImaginary(PetscScalar,PetscScalar,PetscScalar,PetscScalar,PetscInt*,void*);
117: #endif
118: SLEPC_EXTERN PetscErrorCode SlepcCompareSmallestPosReal(PetscScalar,PetscScalar,PetscScalar,PetscScalar,PetscInt*,void*);