Actual source code: ex1f90.F90

  1: !
  2: !
  3: !
  4: ! -----------------------------------------------------------------------

  6:       program main
  7: #include <petsc/finclude/petscvec.h>
  8:       use petscvec
  9:       implicit none

 11: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 12: !                   Variable declarations
 13: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 14: !
 15: !  Variables:
 16: !     x, y, w - vectors
 17: !     z       - array of vectors
 18: !
 19:       Vec              x,y,w
 20:       Vec, pointer :: z(:)
 21:       PetscReal norm,v,v1,v2
 22:       PetscInt         n,ithree
 23:       PetscErrorCode   ierr
 24:       PetscMPIInt      rank
 25:       PetscBool        flg
 26:       PetscScalar      one,two,three
 27:       PetscScalar      dots(3),dot
 28:       PetscReal        nfloat

 30: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 31: !                 Beginning of program
 32: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

 34:       PetscCallA(PetscInitialize(ierr))
 35:       one   = 1.0
 36:       two   = 2.0
 37:       three = 3.0
 38:       n     = 20
 39:       ithree = 3

 41:       PetscCallA(PetscOptionsGetInt(PETSC_NULL_OPTIONS,PETSC_NULL_CHARACTER,'-n',n,flg,ierr))
 42:       nfloat = n
 43:       PetscCallMPIA(MPI_Comm_rank(PETSC_COMM_WORLD,rank,ierr))

 45: !  Create a vector, specifying only its global dimension.
 46: !  When using VecCreate(), VecSetSizes() and VecSetFromOptions(),
 47: !  the vector format (currently parallel
 48: !  or sequential) is determined at runtime.  Also, the parallel
 49: !  partitioning of the vector is determined by PETSc at runtime.
 50: !
 51: !  Routines for creating particular vector types directly are:
 52: !     VecCreateSeq() - uniprocessor vector
 53: !     VecCreateMPI() - distributed vector, where the user can
 54: !                      determine the parallel partitioning

 56:       PetscCallA(VecCreate(PETSC_COMM_WORLD,x,ierr))
 57:       PetscCallA(VecSetSizes(x,PETSC_DECIDE,n,ierr))
 58:       PetscCallA(VecSetFromOptions(x,ierr))

 60: !  Duplicate some work vectors (of the same format and
 61: !  partitioning as the initial vector).

 63:       PetscCallA(VecDuplicate(x,y,ierr))
 64:       PetscCallA(VecDuplicate(x,w,ierr))

 66: !  Duplicate more work vectors (of the same format and
 67: !  partitioning as the initial vector).  Here we duplicate
 68: !  an array of vectors, which is often more convenient than
 69: !  duplicating individual ones.

 71:       PetscCallA(VecDuplicateVecsF90(x,ithree,z,ierr))

 73: !  Set the vectors to entries to a constant value.

 75:       PetscCallA(VecSet(x,one,ierr))
 76:       PetscCallA(VecSet(y,two,ierr))
 77:       PetscCallA(VecSet(z(1),one,ierr))
 78:       PetscCallA(VecSet(z(2),two,ierr))
 79:       PetscCallA(VecSet(z(3),three,ierr))

 81: !  Demonstrate various basic vector routines.

 83:       PetscCallA(VecDot(x,x,dot,ierr))
 84:       PetscCallA(VecMDot(x,ithree,z,dots,ierr))

 86: !  Note: If using a complex numbers version of PETSc, then
 87: !  PETSC_USE_COMPLEX is defined in the makefiles; otherwise,
 88: !  (when using real numbers) it is undefined.

 90:       if (rank .eq. 0) then
 91: #if defined(PETSC_USE_COMPLEX)
 92:          write(6,100) int(PetscRealPart(dot))
 93:          write(6,110) int(PetscRealPart(dots(1))),int(PetscRealPart(dots(2))),int(PetscRealPart(dots(3)))
 94: #else
 95:          write(6,100) int(dot)
 96:          write(6,110) int(dots(1)),int(dots(2)),int(dots(3))
 97: #endif
 98:          write(6,120)
 99:       endif
100:  100  format ('Vector length ',i6)
101:  110  format ('Vector length ',3(i6))
102:  120  format ('All other values should be near zero')

104:       PetscCallA(VecScale(x,two,ierr))
105:       PetscCallA(VecNorm(x,NORM_2,norm,ierr))
106:       v = abs(norm-2.0*sqrt(nfloat))
107:       if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0
108:       if (rank .eq. 0) write(6,130) v
109:  130  format ('VecScale ',1pe9.2)

111:       PetscCallA(VecCopy(x,w,ierr))
112:       PetscCallA(VecNorm(w,NORM_2,norm,ierr))
113:       v = abs(norm-2.0*sqrt(nfloat))
114:       if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0
115:       if (rank .eq. 0) write(6,140) v
116:  140  format ('VecCopy ',1pe9.2)

118:       PetscCallA(VecAXPY(y,three,x,ierr))
119:       PetscCallA(VecNorm(y,NORM_2,norm,ierr))
120:       v = abs(norm-8.0*sqrt(nfloat))
121:       if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0
122:       if (rank .eq. 0) write(6,150) v
123:  150  format ('VecAXPY ',1pe9.2)

125:       PetscCallA(VecAYPX(y,two,x,ierr))
126:       PetscCallA(VecNorm(y,NORM_2,norm,ierr))
127:       v = abs(norm-18.0*sqrt(nfloat))
128:       if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0
129:       if (rank .eq. 0) write(6,160) v
130:  160  format ('VecAYXP ',1pe9.2)

132:       PetscCallA(VecSwap(x,y,ierr))
133:       PetscCallA(VecNorm(y,NORM_2,norm,ierr))
134:       v = abs(norm-2.0*sqrt(nfloat))
135:       if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0
136:       if (rank .eq. 0) write(6,170) v
137:  170  format ('VecSwap ',1pe9.2)

139:       PetscCallA(VecNorm(x,NORM_2,norm,ierr))
140:       v = abs(norm-18.0*sqrt(nfloat))
141:       if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0
142:       if (rank .eq. 0) write(6,180) v
143:  180  format ('VecSwap ',1pe9.2)

145:       PetscCallA(VecWAXPY(w,two,x,y,ierr))
146:       PetscCallA(VecNorm(w,NORM_2,norm,ierr))
147:       v = abs(norm-38.0*sqrt(nfloat))
148:       if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0
149:       if (rank .eq. 0) write(6,190) v
150:  190  format ('VecWAXPY ',1pe9.2)

152:       PetscCallA(VecPointwiseMult(w,y,x,ierr))
153:       PetscCallA(VecNorm(w,NORM_2,norm,ierr))
154:       v = abs(norm-36.0*sqrt(nfloat))
155:       if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0
156:       if (rank .eq. 0) write(6,200) v
157:  200  format ('VecPointwiseMult ',1pe9.2)

159:       PetscCallA(VecPointwiseDivide(w,x,y,ierr))
160:       PetscCallA(VecNorm(w,NORM_2,norm,ierr))
161:       v = abs(norm-9.0*sqrt(nfloat))
162:       if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0
163:       if (rank .eq. 0) write(6,210) v
164:  210  format ('VecPointwiseDivide ',1pe9.2)

166:       dots(1) = one
167:       dots(2) = three
168:       dots(3) = two
169:       PetscCallA(VecSet(x,one,ierr))
170:       PetscCallA(VecMAXPY(x,ithree,dots,z,ierr))
171:       PetscCallA(VecNorm(z(1),NORM_2,norm,ierr))
172:       v = abs(norm-sqrt(nfloat))
173:       if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0
174:       PetscCallA(VecNorm(z(2),NORM_2,norm,ierr))
175:       v1 = abs(norm-2.0*sqrt(nfloat))
176:       if (v1 .gt. -1.d-10 .and. v1 .lt. 1.d-10) v1 = 0.0
177:       PetscCallA(VecNorm(z(3),NORM_2,norm,ierr))
178:       v2 = abs(norm-3.0*sqrt(nfloat))
179:       if (v2 .gt. -1.d-10 .and. v2 .lt. 1.d-10) v2 = 0.0
180:       if (rank .eq. 0) write(6,220) v,v1,v2
181:  220  format ('VecMAXPY ',3(1pe9.2))

183: !  Free work space.  All PETSc objects should be destroyed when they
184: !  are no longer needed.

186:       PetscCallA(VecDestroy(x,ierr))
187:       PetscCallA(VecDestroy(y,ierr))
188:       PetscCallA(VecDestroy(w,ierr))
189:       PetscCallA(VecDestroyVecsF90(ithree,z,ierr))
190:       PetscCallA(PetscFinalize(ierr))

192:       end

194: !
195: !/*TEST
196: !
197: !     test:
198: !       nsize: 2
199: !
200: !TEST*/