1: program main

  3: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  4: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  5: !
  6: !
  7: !     This examples uses Fortran 90 MODULES instead of include files
  8: !
  9: #include <petsc/finclude/petscvec.h>
 10:   use petscvec
 11:   implicit none

 13: !
 14: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 15: !                   Variable declarations
 16: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 17: !
 18: !  Variables:
 19: !     x, y, w - vectors
 20: !     z       - array of vectors
 21: !
 22:   type(tVec) x, y, w
 23:   type(tVec), pointer :: z(:)

 25:   PetscReal norm, v, v1, v2, tol
 26:   PetscInt n, ithree
 27:   PetscErrorCode ierr
 28:   PetscMPIInt rank
 29:   PetscBool flg
 30:   PetscScalar one, two, three
 31:   PetscScalar dots(3), dot
 32:   PetscReal nfloat

 34: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 35: !                 Beginning of program
 36: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

 38:   PetscCallA(PetscInitialize(ierr))
 39:   tol = 1.e-10_PETSC_REAL_KIND
 40:   one = 1.0
 41:   two = 2.0
 42:   three = 3.0
 43:   n = 20
 44:   ithree = 3

 46:   PetscCallA(PetscOptionsGetInt(PETSC_NULL_OPTIONS, PETSC_NULL_CHARACTER, '-n', n, flg, ierr))
 47:   nfloat = n
 48:   PetscCallMPIA(MPI_Comm_rank(PETSC_COMM_WORLD, rank, ierr))

 50: !  Create a vector, specifying only its global dimension.
 51: !  When using VecCreate(), VecSetSizes() and VecSetFromOptions(),
 52: !  the vector format (currently parallel
 53: !  or sequential) is determined at runtime.  Also, the parallel
 54: !  partitioning of the vector is determined by PETSc at runtime.
 55: !
 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(VecDuplicateVecs(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 == 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:   end if
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 > -tol .and. v < tol) v = 0.0
108:   if (rank == 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 > -tol .and. v < tol) v = 0.0
115:   if (rank == 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 > -tol .and. v < tol) v = 0.0
122:   if (rank == 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 > -tol .and. v < tol) v = 0.0
129:   if (rank == 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 > -tol .and. v < tol) v = 0.0
136:   if (rank == 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 > -tol .and. v < tol) v = 0.0
142:   if (rank == 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 > -tol .and. v < tol) v = 0.0
149:   if (rank == 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 > -tol .and. v < tol) v = 0.0
156:   if (rank == 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 > -tol .and. v < tol) v = 0.0
163:   if (rank == 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 > -tol .and. v < tol) v = 0.0
174:   PetscCallA(VecNorm(z(2), NORM_2, norm, ierr))
175:   v1 = abs(norm - 2.0*sqrt(nfloat))
176:   if (v1 > -tol .and. v1 < tol) v1 = 0.0
177:   PetscCallA(VecNorm(z(3), NORM_2, norm, ierr))
178:   v2 = abs(norm - 3.0*sqrt(nfloat))
179:   if (v2 > -tol .and. v2 < tol) v2 = 0.0
180:   if (rank == 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(VecDestroyVecs(ithree, z, ierr))
190:   PetscCallA(PetscFinalize(ierr))

192: end

194: !/*TEST
195: !
196: !     test:
197: !
198: !TEST*/