Actual source code: ex20f90.F90

petsc-3.5.1 2014-07-24
Report Typos and Errors
  1: !
  2: !
  3: !/*T
  4: !   Concepts: vectors^using basic vector routines;
  5: !   Concepts: Fortran90^using basic vector routines;
  6: !   Processors: n
  7: !T*/
  8: !
  9: ! -----------------------------------------------------------------------

 11:       program main

 13: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 14: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 15: !
 16: !
 17: !     This examples uses Fortran 90 MODULES instead of include files
 18: !   see the manual page UsingFortran
 19: !
 20: #define PETSC_USE_FORTRAN_MODULES
 21: #include <finclude/petscsysdef.h>
 22: #include <finclude/petscvecdef.h>
 23: #if defined(PETSC_USE_FORTRAN_MODULES)
 24:       use petscvec
 25: #endif
 26:       implicit none
 27: #if !defined(PETSC_USE_FORTRAN_MODULES)
 28: #include <finclude/petscsys.h>
 29: #include <finclude/petscvec.h>
 30: #include <finclude/petscvec.h90>

 32: #endif
 33: !
 34: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 35: !                   Variable declarations
 36: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 37: !
 38: !  Variables:
 39: !     x, y, w - vectors
 40: !     z       - array of vectors
 41: !
 42: #if defined(PETSC_USE_FORTRAN_DATATYPES)
 43:       type(Vec)       x,y,w
 44:       type(Vec), pointer :: z(:)
 45: #else
 46:       Vec              x,y,w
 47:       Vec, pointer :: z(:)
 48: #endif
 49:       PetscReal norm,v,v1,v2
 50:       PetscInt  n,ithree
 51:       PetscErrorCode ierr
 52:       PetscMPIInt  rank
 53:       PetscBool       flg
 54:       PetscScalar      one,two,three
 55:       PetscScalar      dots(3),dot

 57: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 58: !                 Beginning of program
 59: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

 61:       call PetscInitialize(PETSC_NULL_CHARACTER,ierr)
 62:       one   = 1.0
 63:       two   = 2.0
 64:       three = 3.0
 65:       n     = 20
 66:       ithree = 3

 68:       call PetscOptionsGetInt(PETSC_NULL_CHARACTER,'-n',n,flg,ierr)
 69:       call MPI_Comm_rank(PETSC_COMM_WORLD,rank,ierr)

 71: !  Create a vector, specifying only its global dimension.
 72: !  When using VecCreate(), VecSetSizes() and VecSetFromOptions(),
 73: !  the vector format (currently parallel
 74: !  or sequential) is determined at runtime.  Also, the parallel
 75: !  partitioning of the vector is determined by PETSc at runtime.
 76: !
 77: !  Routines for creating particular vector types directly are:
 78: !     VecCreateSeq() - uniprocessor vector
 79: !     VecCreateMPI() - distributed vector, where the user can
 80: !                      determine the parallel partitioning

 82:       call VecCreate(PETSC_COMM_WORLD,x,ierr)
 83:       call VecSetSizes(x,PETSC_DECIDE,n,ierr)
 84:       call VecSetFromOptions(x,ierr)

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

 89:       call VecDuplicate(x,y,ierr)
 90:       call VecDuplicate(x,w,ierr)

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

 97:       call VecDuplicateVecsF90(x,ithree,z,ierr)

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

101:       call VecSet(x,one,ierr)
102:       call VecSet(y,two,ierr)
103:       call VecSet(z(1),one,ierr)
104:       call VecSet(z(2),two,ierr)
105:       call VecSet(z(3),three,ierr)

107: !  Demonstrate various basic vector routines.

109:       call VecDot(x,x,dot,ierr)
110:       call VecMDot(x,ithree,z,dots,ierr)

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

116:       if (rank .eq. 0) then
117: #if defined(PETSC_USE_COMPLEX)
118:          write(6,100) int(PetscRealPart(dot))
119:          write(6,110) int(PetscRealPart(dots(1))),                               &
120:      &                int(PetscRealPart(dots(2))),                               &
121:      &                int(PetscRealPart(dots(3)))
122: #else
123:          write(6,100) int(dot)
124:          write(6,110) int(dots(1)),int(dots(2)),int(dots(3))
125: #endif
126:          write(6,120)
127:       endif
128:  100  format ("Vector length ",i6)
129:  110  format ("Vector length ",3(i6))
130:  120  format ("All other values should be near zero")

132:       call VecScale(x,two,ierr)
133:       call VecNorm(x,NORM_2,norm,ierr)
134:       v = norm-2.0*sqrt(dble(n))
135:       if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0
136:       if (rank .eq. 0) write(6,130) v
137:  130  format ("VecScale ",1pe8.2)

139:       call VecCopy(x,w,ierr)
140:       call VecNorm(w,NORM_2,norm,ierr)
141:       v = norm-2.0*sqrt(dble(n))
142:       if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0
143:       if (rank .eq. 0) write(6,140) v
144:  140  format ("VecCopy ",1pe8.2)

146:       call VecAXPY(y,three,x,ierr)
147:       call VecNorm(y,NORM_2,norm,ierr)
148:       v = norm-8.0*sqrt(dble(n))
149:       if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0
150:       if (rank .eq. 0) write(6,150) v
151:  150  format ("VecAXPY ",1pe8.2)

153:       call VecAYPX(y,two,x,ierr)
154:       call VecNorm(y,NORM_2,norm,ierr)
155:       v = norm-18.0*sqrt(dble(n))
156:       if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0
157:       if (rank .eq. 0) write(6,160) v
158:  160  format ("VecAYXP ",1pe8.2)

160:       call VecSwap(x,y,ierr)
161:       call VecNorm(y,NORM_2,norm,ierr)
162:       v = norm-2.0*sqrt(dble(n))
163:       if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0
164:       if (rank .eq. 0) write(6,170) v
165:  170  format ("VecSwap ",1pe8.2)

167:       call VecNorm(x,NORM_2,norm,ierr)
168:       v = norm-18.0*sqrt(dble(n))
169:       if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0
170:       if (rank .eq. 0) write(6,180) v
171:  180  format ("VecSwap ",1pe8.2)

173:       call VecWAXPY(w,two,x,y,ierr)
174:       call VecNorm(w,NORM_2,norm,ierr)
175:       v = norm-38.0*sqrt(dble(n))
176:       if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0
177:       if (rank .eq. 0) write(6,190) v
178:  190  format ("VecWAXPY ",1pe8.2)

180:       call VecPointwiseMult(w,y,x,ierr)
181:       call VecNorm(w,NORM_2,norm,ierr)
182:       v = norm-36.0*sqrt(dble(n))
183:       if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0
184:       if (rank .eq. 0) write(6,200) v
185:  200  format ("VecPointwiseMult ",1pe8.2)

187:       call VecPointwiseDivide(w,x,y,ierr)
188:       call VecNorm(w,NORM_2,norm,ierr)
189:       v = norm-9.0*sqrt(dble(n))
190:       if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0
191:       if (rank .eq. 0) write(6,210) v
192:  210  format ("VecPointwiseDivide ",1pe8.2)


195:       dots(1) = one
196:       dots(2) = three
197:       dots(3) = two
198:       call VecSet(x,one,ierr)
199:       call VecMAXPY(x,ithree,dots,z,ierr)
200:       call VecNorm(z(1),NORM_2,norm,ierr)
201:       v = norm-sqrt(dble(n))
202:       if (v .gt. -1.d-10 .and. v .lt. 1.d-10) v = 0.0
203:       call VecNorm(z(2),NORM_2,norm,ierr)
204:       v1 = norm-2.0*sqrt(dble(n))
205:       if (v1 .gt. -1.d-10 .and. v1 .lt. 1.d-10) v1 = 0.0
206:       call VecNorm(z(3),NORM_2,norm,ierr)
207:       v2 = norm-3.0*sqrt(dble(n))
208:       if (v2 .gt. -1.d-10 .and. v2 .lt. 1.d-10) v2 = 0.0
209:       if (rank .eq. 0) write(6,220) v,v1,v2
210:  220  format ("VecMAXPY ",3(1pe8.2))


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

216:       call VecDestroy(x,ierr)
217:       call VecDestroy(y,ierr)
218:       call VecDestroy(w,ierr)
219:       call VecDestroyVecsF90(ithree,z,ierr)
220:       call PetscFinalize(ierr)

222:       end