Actual source code: vecutil.c
slepc-3.10.1 2018-10-23
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      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-2018, 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: */

     11: #include <slepc/private/vecimplslepc.h>       /*I "slepcvec.h" I*/

     13: /*@
     14:    VecNormalizeComplex - Normalizes a possibly complex vector by the 2-norm.

     16:    Collective on Vec

     18:    Input parameters:
     19: +  xr - the real part of the vector (overwritten on output)
     20: .  xi - the imaginary part of the vector (not referenced if iscomplex is false)
     21: -  iscomplex - a flag indicating if the vector is complex

     23:    Output parameter:
     24: .  norm - the vector norm before normalization (can be set to NULL)

     26:    Level: developer
     27: @*/
     28: PetscErrorCode VecNormalizeComplex(Vec xr,Vec xi,PetscBool iscomplex,PetscReal *norm)
     29: {
     31: #if !defined(PETSC_USE_COMPLEX)
     32:   PetscReal      normr,normi,alpha;
     33: #endif

     37: #if !defined(PETSC_USE_COMPLEX)
     38:   if (iscomplex) {
     40:     VecNormBegin(xr,NORM_2,&normr);
     41:     VecNormBegin(xi,NORM_2,&normi);
     42:     VecNormEnd(xr,NORM_2,&normr);
     43:     VecNormEnd(xi,NORM_2,&normi);
     44:     alpha = SlepcAbsEigenvalue(normr,normi);
     45:     if (norm) *norm = alpha;
     46:     alpha = 1.0 / alpha;
     47:     VecScale(xr,alpha);
     48:     VecScale(xi,alpha);
     49:   } else
     50: #endif
     51:   {
     52:     VecNormalize(xr,norm);
     53:   }
     54:   return(0);
     55: }

     57: /*@C
     58:    VecCheckOrthogonality - Checks (or prints) the level of orthogonality
     59:    of a set of vectors.

     61:    Collective on Vec

     63:    Input parameters:
     64: +  V  - a set of vectors
     65: .  nv - number of V vectors
     66: .  W  - an alternative set of vectors (optional)
     67: .  nw - number of W vectors
     68: .  B  - matrix defining the inner product (optional)
     69: -  viewer - optional visualization context

     71:    Output parameter:
     72: .  lev - level of orthogonality (optional)

     74:    Notes:
     75:    This function computes W'*V and prints the result. It is intended to check
     76:    the level of bi-orthogonality of the vectors in the two sets. If W is equal
     77:    to NULL then V is used, thus checking the orthogonality of the V vectors.

     79:    If matrix B is provided then the check uses the B-inner product, W'*B*V.

     81:    If lev is not NULL, it will contain the maximum entry of matrix
     82:    W'*V - I (in absolute value). Otherwise, the matrix W'*V is printed.

     84:    Level: developer
     85: @*/
     86: PetscErrorCode VecCheckOrthogonality(Vec *V,PetscInt nv,Vec *W,PetscInt nw,Mat B,PetscViewer viewer,PetscReal *lev)
     87: {
     89:   PetscInt       i,j;
     90:   PetscScalar    *vals;
     91:   PetscBool      isascii;
     92:   Vec            w;

     95:   if (nv<=0 || nw<=0) return(0);
     98:   if (!lev) {
     99:     if (!viewer) viewer = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)*V));
    102:     PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isascii);
    103:     if (!isascii) return(0);
    104:   }

    106:   PetscMalloc1(nv,&vals);
    107:   if (B) {
    108:     VecDuplicate(V[0],&w);
    109:   }
    110:   if (lev) *lev = 0.0;
    111:   for (i=0;i<nw;i++) {
    112:     if (B) {
    113:       if (W) {
    114:         MatMultTranspose(B,W[i],w);
    115:       } else {
    116:         MatMultTranspose(B,V[i],w);
    117:       }
    118:     } else {
    119:       if (W) w = W[i];
    120:       else w = V[i];
    121:     }
    122:     VecMDot(w,nv,V,vals);
    123:     for (j=0;j<nv;j++) {
    124:       if (lev) *lev = PetscMax(*lev,PetscAbsScalar((j==i)? (vals[j]-1.0): vals[j]));
    125:       else {
    126: #if !defined(PETSC_USE_COMPLEX)
    127:         PetscViewerASCIIPrintf(viewer," %12g  ",(double)vals[j]);
    128: #else
    129:         PetscViewerASCIIPrintf(viewer," %12g%+12gi ",(double)PetscRealPart(vals[j]),(double)PetscImaginaryPart(vals[j]));
    130: #endif
    131:       }
    132:     }
    133:     if (!lev) { PetscViewerASCIIPrintf(viewer,"\n"); }
    134:   }
    135:   PetscFree(vals);
    136:   if (B) {
    137:     VecDestroy(&w);
    138:   }
    139:   return(0);
    140: }

    142: /*@
    143:    VecDuplicateEmpty - Creates a new vector of the same type as an existing vector,
    144:    but without internal array.

    146:    Collective on Vec

    148:    Input parameters:
    149: .  v - a vector to mimic

    151:    Output parameter:
    152: .  newv - location to put new vector

    154:    Note:
    155:    This is similar to VecDuplicate(), but the new vector does not have an internal
    156:    array, so the intended usage is with VecPlaceArray().

    158:    Level: developer
    159: @*/
    160: PetscErrorCode VecDuplicateEmpty(Vec v,Vec *newv)
    161: {
    163:   PetscBool      sup,cuda,mpi;
    164:   PetscInt       N,nloc,bs;

    171:   PetscObjectTypeCompareAny((PetscObject)v,&sup,VECSEQ,VECMPI,VECSEQCUDA,VECMPICUDA,"");
    172:   if (!sup) SETERRQ1(PetscObjectComm((PetscObject)v),PETSC_ERR_SUP,"Vector type %s not supported",((PetscObject)v)->type_name);
    173:   PetscObjectTypeCompareAny((PetscObject)v,&cuda,VECSEQCUDA,VECMPICUDA,"");
    174:   PetscObjectTypeCompareAny((PetscObject)v,&mpi,VECMPI,VECMPICUDA,"");
    175:   VecGetLocalSize(v,&nloc);
    176:   VecGetSize(v,&N);
    177:   VecGetBlockSize(v,&bs);

    179:   if (cuda) {
    180: #if defined(PETSC_HAVE_VECCUDA)
    181:     if (mpi) {
    182:       VecCreateMPICUDAWithArray(PetscObjectComm((PetscObject)v),bs,nloc,N,NULL,newv);
    183:     } else {
    184:       VecCreateSeqCUDAWithArray(PetscObjectComm((PetscObject)v),bs,N,NULL,newv);
    185:     }
    186: #endif
    187:   } else {
    188:     if (mpi) {
    189:       VecCreateMPIWithArray(PetscObjectComm((PetscObject)v),bs,nloc,N,NULL,newv);
    190:     } else {
    191:       VecCreateSeqWithArray(PetscObjectComm((PetscObject)v),bs,N,NULL,newv);
    192:     }
    193:   }
    194:   return(0);
    195: }