Actual source code: ex1f.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
19: Vec :: x,y,w
20: Vec, dimension(5) :: z
21: PetscReal :: norm,v,v1,v2
22: PetscInt, parameter :: &
23: ithree = 3, &
24: n = 20
25: PetscBool :: flg
26: PetscErrorCode :: ierr
27: PetscMPIInt :: rank
28: PetscScalar, parameter :: &
29: one = 1.0, &
30: two = 2.0, &
31: three = 3.0
32: PetscScalar :: dot
33: PetscScalar, dimension(3) :: dots
34: character(len=PETSC_MAX_PATH_LEN) :: name
35: PetscReal :: nfloat
37: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
38: ! Beginning of program
39: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
41: call PetscInitialize(PETSC_NULL_CHARACTER,ierr)
42: if (ierr /= 0) then
43: print*,'Unable to initialize PETSc'
44: stop
45: endif
46: call PetscOptionsGetInt(PETSC_NULL_OPTIONS,PETSC_NULL_CHARACTER,'-n',n,flg,ierr)
47: nfloat = n
48: call 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: ! Routines for creating particular vector types directly are:
57: ! VecCreateSeq() - uniprocessor vector
58: ! VecCreateMPI() - distributed vector, where the user can
59: ! determine the parallel partitioning
60: ! VecCreateShared() - parallel vector that uses shared memory
61: ! (available only on the SGI); otherwise,
62: ! is the same as VecCreateMPI()
63: !
64: ! VecCreate(), VecSetSizes() and VecSetFromOptions() allows one
65: ! to determine at runtime which version to use
66: ! with the options -vec_type mpi or -vec_type shared
67: !
68: call VecCreate(PETSC_COMM_WORLD,x,ierr)
69: call VecSetSizes(x,PETSC_DECIDE,n,ierr)
70: call VecSetFromOptions(x,ierr)
71: call VecGetType(x,name,ierr)
73: ! Duplicate some work vectors (of the same format and
74: ! partitioning as the initial vector).
76: call VecDuplicate(x,y,ierr)
77: call VecDuplicate(x,w,ierr)
79: ! Duplicate more work vectors (of the same format and
80: ! partitioning as the initial vector). Here we duplicate
81: ! an array of vectors, which is often more convenient than
82: ! duplicating individual ones.
84: call VecDuplicateVecs(x,ithree,z,ierr)
86: ! Set the vectors to entries to a constant value.
88: call VecSet(x,one,ierr)
90: call VecSet(y,two,ierr)
91: call VecSet(z(1),one,ierr)
92: call VecSet(z(2),two,ierr)
93: call VecSet(z(3),three,ierr)
95: ! Demonstrate various basic vector routines.
97: call VecDot(x,x,dot,ierr)
98: call VecMDot(x,ithree,z,dots,ierr)
100: ! Note: If using a complex numbers version of PETSc, then
101: ! PETSC_USE_COMPLEX is defined in the makefiles; otherwise,
102: ! (when using real numbers) it is undefined.
104: if (rank .eq. 0) then
105: #if defined(PETSC_USE_COMPLEX)
106: write(6,100) int(PetscRealPart(dot))
107: write(6,110) int(PetscRealPart(dots(1))),int(PetscRealPart(dots(2))),int(PetscRealPart(dots(3)))
108: #else
109: write(6,100) int(dot)
110: write(6,110) int(dots(1)),int(dots(2)),int(dots(3))
111: #endif
112: write(6,120)
113: endif
114: 100 format ('Vector length ',i6)
115: 110 format ('Vector length ',3(i6))
116: 120 format ('All other values should be near zero')
118: call VecScale(x,two,ierr)
119: call VecNorm(x,NORM_2,norm,ierr)
120: v = abs(norm-2.0*sqrt(nfloat))
121: if (v .gt. -PETSC_SMALL .and. v .lt. PETSC_SMALL) v = 0.0
122: if (rank == 0) write(6,130) v
123: 130 format ('VecScale ',1pe9.2)
125: call VecCopy(x,w,ierr)
126: call VecNorm(w,NORM_2,norm,ierr)
127: v = abs(norm-2.0*sqrt(nfloat))
128: if (v .gt. -PETSC_SMALL .and. v .lt. PETSC_SMALL) v = 0.0
129: if (rank == 0) write(6,140) v
130: 140 format ('VecCopy ',1pe9.2)
132: call VecAXPY(y,three,x,ierr)
133: call VecNorm(y,NORM_2,norm,ierr)
134: v = abs(norm-8.0*sqrt(nfloat))
135: if (v .gt. -PETSC_SMALL .and. v .lt. PETSC_SMALL) v = 0.0
136: if (rank == 0) write(6,150) v
137: 150 format ('VecAXPY ',1pe9.2)
139: call VecAYPX(y,two,x,ierr)
140: call VecNorm(y,NORM_2,norm,ierr)
141: v = abs(norm-18.0*sqrt(nfloat))
142: if (v .gt. -PETSC_SMALL .and. v .lt. PETSC_SMALL) v = 0.0
143: if (rank == 0) write(6,160) v
144: 160 format ('VecAYXP ',1pe9.2)
146: call VecSwap(x,y,ierr)
147: call VecNorm(y,NORM_2,norm,ierr)
148: v = abs(norm-2.0*sqrt(nfloat))
149: if (v .gt. -PETSC_SMALL .and. v .lt. PETSC_SMALL) v = 0.0
150: if (rank == 0) write(6,170) v
151: 170 format ('VecSwap ',1pe9.2)
153: call VecNorm(x,NORM_2,norm,ierr)
154: v = abs(norm-18.0*sqrt(nfloat))
155: if (v .gt. -PETSC_SMALL .and. v .lt. PETSC_SMALL) v = 0.0
156: if (rank == 0) write(6,180) v
157: 180 format ('VecSwap ',1pe9.2)
159: call VecWAXPY(w,two,x,y,ierr)
160: call VecNorm(w,NORM_2,norm,ierr)
161: v = abs(norm-38.0*sqrt(nfloat))
162: if (v .gt. -PETSC_SMALL .and. v .lt. PETSC_SMALL) v = 0.0
163: if (rank == 0) write(6,190) v
164: 190 format ('VecWAXPY ',1pe9.2)
166: call VecPointwiseMult(w,y,x,ierr)
167: call VecNorm(w,NORM_2,norm,ierr)
168: v = abs(norm-36.0*sqrt(nfloat))
169: if (v .gt. -PETSC_SMALL .and. v .lt. PETSC_SMALL) v = 0.0
170: if (rank == 0) write(6,200) v
171: 200 format ('VecPointwiseMult ',1pe9.2)
173: call VecPointwiseDivide(w,x,y,ierr)
174: call VecNorm(w,NORM_2,norm,ierr)
175: v = abs(norm-9.0*sqrt(nfloat))
176: if (v .gt. -PETSC_SMALL .and. v .lt. PETSC_SMALL) v = 0.0
177: if (rank == 0) write(6,210) v
178: 210 format ('VecPointwiseDivide ',1pe9.2)
180: dots(1) = one
181: dots(2) = three
182: dots(3) = two
183: call VecSet(x,one,ierr)
184: call VecMAXPY(x,ithree,dots,z,ierr)
185: call VecNorm(z(1),NORM_2,norm,ierr)
186: v = abs(norm-sqrt(nfloat))
187: if (v .gt. -PETSC_SMALL .and. v .lt. PETSC_SMALL) v = 0.0
188: call VecNorm(z(2),NORM_2,norm,ierr)
189: v1 = abs(norm-2.0*sqrt(nfloat))
190: if (v1 .gt. -PETSC_SMALL .and. v1 .lt. PETSC_SMALL) v1 = 0.0
191: call VecNorm(z(3),NORM_2,norm,ierr)
192: v2 = abs(norm-3.0*sqrt(nfloat))
193: if (v2 .gt. -PETSC_SMALL .and. v2 .lt. PETSC_SMALL) v2 = 0.0
194: if (rank .eq. 0) write(6,220) v,v1,v2
195: 220 format ('VecMAXPY ',3(2x,1pe9.2))
197: ! Free work space. All PETSc objects should be destroyed when they
198: ! are no longer needed.
200: call VecDestroy(x,ierr)
201: call VecDestroy(y,ierr)
202: call VecDestroy(w,ierr)
203: call VecDestroyVecs(ithree,z,ierr)
204: call PetscFinalize(ierr)
206: end
208: !
209: !/*TEST
210: !
211: ! test:
212: ! suffix: 1
213: !
214: ! test:
215: ! suffix: 2
216: ! nsize: 2
217: !
218: !TEST*/