Actual source code: ex20f90.F90
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: !
19: #include <petsc/finclude/petscvec.h>
20: use petscvec
21: implicit none
23: !
24: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
25: ! Variable declarations
26: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
27: !
28: ! Variables:
29: ! x, y, w - vectors
30: ! z - array of vectors
31: !
32: type(tVec) x,y,w
33: type(tVec), pointer :: z(:)
35: PetscReal norm,v,v1,v2,tol
36: PetscInt n,ithree
37: PetscErrorCode ierr
38: PetscMPIInt rank
39: PetscBool flg
40: PetscScalar one,two,three
41: PetscScalar dots(3),dot
42: PetscReal nfloat
44: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
45: ! Beginning of program
46: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
48: call PetscInitialize(PETSC_NULL_CHARACTER,ierr)
49: if (ierr .ne. 0) then
50: print*,'Unable to initialize PETSc'
51: stop
52: endif
54: tol = 1.e-10_PETSC_REAL_KIND
55: one = 1.0
56: two = 2.0
57: three = 3.0
58: n = 20
59: ithree = 3
61: call PetscOptionsGetInt(PETSC_NULL_OPTIONS,PETSC_NULL_CHARACTER,'-n',n,flg,ierr);CHKERRA(ierr)
62: nfloat = n
63: call MPI_Comm_rank(PETSC_COMM_WORLD,rank,ierr);CHKERRA(ierr)
65: ! Create a vector, specifying only its global dimension.
66: ! When using VecCreate(), VecSetSizes() and VecSetFromOptions(),
67: ! the vector format (currently parallel
68: ! or sequential) is determined at runtime. Also, the parallel
69: ! partitioning of the vector is determined by PETSc at runtime.
70: !
71: ! Routines for creating particular vector types directly are:
72: ! VecCreateSeq() - uniprocessor vector
73: ! VecCreateMPI() - distributed vector, where the user can
74: ! determine the parallel partitioning
76: call VecCreate(PETSC_COMM_WORLD,x,ierr);CHKERRA(ierr)
77: call VecSetSizes(x,PETSC_DECIDE,n,ierr);CHKERRA(ierr)
78: call VecSetFromOptions(x,ierr);CHKERRA(ierr)
80: ! Duplicate some work vectors (of the same format and
81: ! partitioning as the initial vector).
83: call VecDuplicate(x,y,ierr);CHKERRA(ierr)
84: call VecDuplicate(x,w,ierr);CHKERRA(ierr)
86: ! Duplicate more work vectors (of the same format and
87: ! partitioning as the initial vector). Here we duplicate
88: ! an array of vectors, which is often more convenient than
89: ! duplicating individual ones.
91: call VecDuplicateVecsF90(x,ithree,z,ierr);CHKERRA(ierr)
93: ! Set the vectors to entries to a constant value.
95: call VecSet(x,one,ierr);CHKERRA(ierr)
96: call VecSet(y,two,ierr);CHKERRA(ierr)
97: call VecSet(z(1),one,ierr);CHKERRA(ierr)
98: call VecSet(z(2),two,ierr);CHKERRA(ierr)
99: call VecSet(z(3),three,ierr);CHKERRA(ierr)
101: ! Demonstrate various basic vector routines.
103: call VecDot(x,x,dot,ierr);CHKERRA(ierr)
104: call VecMDot(x,ithree,z,dots,ierr);CHKERRA(ierr)
106: ! Note: If using a complex numbers version of PETSc, then
107: ! PETSC_USE_COMPLEX is defined in the makefiles; otherwise,
108: ! (when using real numbers) it is undefined.
110: if (rank .eq. 0) then
111: #if defined(PETSC_USE_COMPLEX)
112: write(6,100) int(PetscRealPart(dot))
113: write(6,110) int(PetscRealPart(dots(1))),int(PetscRealPart(dots(2))),int(PetscRealPart(dots(3)))
114: #else
115: write(6,100) int(dot)
116: write(6,110) int(dots(1)),int(dots(2)),int(dots(3))
117: #endif
118: write(6,120)
119: endif
120: 100 format ('Vector length ',i6)
121: 110 format ('Vector length ',3(i6))
122: 120 format ('All other values should be near zero')
124: call VecScale(x,two,ierr);CHKERRA(ierr)
125: call VecNorm(x,NORM_2,norm,ierr);CHKERRA(ierr)
126: v = abs(norm-2.0*sqrt(nfloat))
127: if (v .gt. -tol .and. v .lt. tol) v = 0.0
128: if (rank .eq. 0) write(6,130) v
129: 130 format ('VecScale ',1pe9.2)
131: call VecCopy(x,w,ierr);CHKERRA(ierr)
132: call VecNorm(w,NORM_2,norm,ierr);CHKERRA(ierr)
133: v = abs(norm-2.0*sqrt(nfloat))
134: if (v .gt. -tol .and. v .lt. tol) v = 0.0
135: if (rank .eq. 0) write(6,140) v
136: 140 format ('VecCopy ',1pe9.2)
138: call VecAXPY(y,three,x,ierr);CHKERRA(ierr)
139: call VecNorm(y,NORM_2,norm,ierr);CHKERRA(ierr)
140: v = abs(norm-8.0*sqrt(nfloat))
141: if (v .gt. -tol .and. v .lt. tol) v = 0.0
142: if (rank .eq. 0) write(6,150) v
143: 150 format ('VecAXPY ',1pe9.2)
145: call VecAYPX(y,two,x,ierr);CHKERRA(ierr)
146: call VecNorm(y,NORM_2,norm,ierr);CHKERRA(ierr)
147: v = abs(norm-18.0*sqrt(nfloat))
148: if (v .gt. -tol .and. v .lt. tol) v = 0.0
149: if (rank .eq. 0) write(6,160) v
150: 160 format ('VecAYXP ',1pe9.2)
152: call VecSwap(x,y,ierr);CHKERRA(ierr)
153: call VecNorm(y,NORM_2,norm,ierr);CHKERRA(ierr)
154: v = abs(norm-2.0*sqrt(nfloat))
155: if (v .gt. -tol .and. v .lt. tol) v = 0.0
156: if (rank .eq. 0) write(6,170) v
157: 170 format ('VecSwap ',1pe9.2)
159: call VecNorm(x,NORM_2,norm,ierr);CHKERRA(ierr)
160: v = abs(norm-18.0*sqrt(nfloat))
161: if (v .gt. -tol .and. v .lt. tol) v = 0.0
162: if (rank .eq. 0) write(6,180) v
163: 180 format ('VecSwap ',1pe9.2)
165: call VecWAXPY(w,two,x,y,ierr);CHKERRA(ierr)
166: call VecNorm(w,NORM_2,norm,ierr);CHKERRA(ierr)
167: v = abs(norm-38.0*sqrt(nfloat))
168: if (v .gt. -tol .and. v .lt. tol) v = 0.0
169: if (rank .eq. 0) write(6,190) v
170: 190 format ('VecWAXPY ',1pe9.2)
172: call VecPointwiseMult(w,y,x,ierr);CHKERRA(ierr)
173: call VecNorm(w,NORM_2,norm,ierr);CHKERRA(ierr)
174: v = abs(norm-36.0*sqrt(nfloat))
175: if (v .gt. -tol .and. v .lt. tol) v = 0.0
176: if (rank .eq. 0) write(6,200) v
177: 200 format ('VecPointwiseMult ',1pe9.2)
179: call VecPointwiseDivide(w,x,y,ierr);CHKERRA(ierr)
180: call VecNorm(w,NORM_2,norm,ierr);CHKERRA(ierr)
181: v = abs(norm-9.0*sqrt(nfloat))
182: if (v .gt. -tol .and. v .lt. tol) v = 0.0
183: if (rank .eq. 0) write(6,210) v
184: 210 format ('VecPointwiseDivide ',1pe9.2)
187: dots(1) = one
188: dots(2) = three
189: dots(3) = two
190: call VecSet(x,one,ierr);CHKERRA(ierr)
191: call VecMAXPY(x,ithree,dots,z,ierr);CHKERRA(ierr)
192: call VecNorm(z(1),NORM_2,norm,ierr);CHKERRA(ierr)
193: v = abs(norm-sqrt(nfloat))
194: if (v .gt. -tol .and. v .lt. tol) v = 0.0
195: call VecNorm(z(2),NORM_2,norm,ierr);CHKERRA(ierr)
196: v1 = abs(norm-2.0*sqrt(nfloat))
197: if (v1 .gt. -tol .and. v1 .lt. tol) v1 = 0.0
198: call VecNorm(z(3),NORM_2,norm,ierr);CHKERRA(ierr)
199: v2 = abs(norm-3.0*sqrt(nfloat))
200: if (v2 .gt. -tol .and. v2 .lt. tol) v2 = 0.0
201: if (rank .eq. 0) write(6,220) v,v1,v2
202: 220 format ('VecMAXPY ',3(1pe9.2))
205: ! Free work space. All PETSc objects should be destroyed when they
206: ! are no longer needed.
208: call VecDestroy(x,ierr);CHKERRA(ierr)
209: call VecDestroy(y,ierr);CHKERRA(ierr)
210: call VecDestroy(w,ierr);CHKERRA(ierr)
211: call VecDestroyVecsF90(ithree,z,ierr);CHKERRA(ierr)
212: call PetscFinalize(ierr)
214: end
216: !/*TEST
217: !
218: ! test:
219: !
220: !TEST*/