/[escript]/trunk/escript/py_src/flows.py
ViewVC logotype

Contents of /trunk/escript/py_src/flows.py

Parent Directory Parent Directory | Revision Log Revision Log


Revision 1517 - (show annotations)
Fri Apr 18 02:36:37 2008 UTC (11 years, 5 months ago) by artak
File MIME type: text/x-python
File size: 4735 byte(s)
stopping criteriums are combined for GMRES,MINRES and TFQMR in stoppingcriterium2
1 # $Id:$
2 #
3 #######################################################
4 #
5 # Copyright 2008 by University of Queensland
6 #
7 # http://esscc.uq.edu.au
8 # Primary Business: Queensland, Australia
9 # Licensed under the Open Software License version 3.0
10 # http://www.opensource.org/licenses/osl-3.0.php
11 #
12 #######################################################
13 #
14
15 """
16 Some models for flow
17
18 @var __author__: name of author
19 @var __copyright__: copyrights
20 @var __license__: licence agreement
21 @var __url__: url entry point on documentation
22 @var __version__: version
23 @var __date__: date of the version
24 """
25
26 __author__="Lutz Gross, l.gross@uq.edu.au"
27 __copyright__=""" Copyright (c) 2008 by ACcESS MNRF
28 http://www.access.edu.au
29 Primary Business: Queensland, Australia"""
30 __license__="""Licensed under the Open Software License version 3.0
31 http://www.opensource.org/licenses/osl-3.0.php"""
32 __url__="http://www.iservo.edu.au/esys"
33 __version__="$Revision:$"
34 __date__="$Date:$"
35
36 from escript import *
37 import util
38 from linearPDEs import LinearPDE
39 from pdetools import HomogeneousSaddlePointProblem
40
41 class StokesProblemCartesian(HomogeneousSaddlePointProblem):
42 """
43 solves
44
45 -(eta*(u_{i,j}+u_{j,i}))_j - p_i = f_i
46 u_{i,i}=0
47
48 u=0 where fixed_u_mask>0
49 eta*(u_{i,j}+u_{j,i})*n_j=surface_stress
50
51 if surface_stress is not give 0 is assumed.
52
53 typical usage:
54
55 sp=StokesProblemCartesian(domain)
56 sp.setTolerance()
57 sp.initialize(...)
58 v,p=sp.solve(v0,p0)
59 """
60 def __init__(self,domain,**kwargs):
61 HomogeneousSaddlePointProblem.__init__(self,**kwargs)
62 self.domain=domain
63 self.vol=util.integrate(1.,Function(self.domain))
64 self.__pde_u=LinearPDE(domain,numEquations=self.domain.getDim(),numSolutions=self.domain.getDim())
65 self.__pde_u.setSymmetryOn()
66 # self.__pde_u.setSolverMethod(preconditioner=LinearPDE.ILU0)
67
68 self.__pde_prec=LinearPDE(domain)
69 self.__pde_prec.setReducedOrderOn()
70 self.__pde_prec.setSymmetryOn()
71
72 self.__pde_proj=LinearPDE(domain)
73 self.__pde_proj.setReducedOrderOn()
74 self.__pde_proj.setSymmetryOn()
75 self.__pde_proj.setValue(D=1.)
76
77 def initialize(self,f=Data(),fixed_u_mask=Data(),eta=1,surface_stress=Data()):
78 self.eta=eta
79 A =self.__pde_u.createCoefficientOfGeneralPDE("A")
80 self.__pde_u.setValue(A=Data())
81 for i in range(self.domain.getDim()):
82 for j in range(self.domain.getDim()):
83 A[i,j,j,i] += 1.
84 A[i,j,i,j] += 1.
85 self.__pde_prec.setValue(D=1./self.eta)
86 self.__pde_u.setValue(A=A*self.eta,q=fixed_u_mask,Y=f,y=surface_stress)
87
88 def B(self,arg):
89 d=util.div(arg)
90 self.__pde_proj.setValue(Y=d)
91 self.__pde_proj.setTolerance(self.getSubProblemTolerance())
92 return self.__pde_proj.getSolution(verbose=self.show_details)
93
94 def inner(self,p0,p1):
95 s0=util.interpolate(p0,Function(self.domain))
96 s1=util.interpolate(p1,Function(self.domain))
97 return util.integrate(s0*s1)
98
99 def getStress(self,u):
100 mg=util.grad(u)
101 return 2.*self.eta*util.symmetric(mg)
102
103 def solve_A(self,u,p):
104 """
105 solves Av=f-Au-B^*p (v=0 on fixed_u_mask)
106 """
107 self.__pde_u.setTolerance(self.getSubProblemTolerance())
108 self.__pde_u.setValue(X=-self.getStress(u)-p*util.kronecker(self.domain))
109 return self.__pde_u.getSolution(verbose=self.show_details)
110
111 def solve_prec(self,p):
112 self.__pde_prec.setTolerance(self.getSubProblemTolerance())
113 self.__pde_prec.setValue(Y=p)
114 q=self.__pde_prec.getSolution(verbose=self.show_details)
115 return q
116 def stoppingcriterium(self,Bv,v,p):
117 n_r=util.sqrt(self.inner(Bv,Bv))
118 n_v=util.Lsup(v)
119 if self.verbose: print "PCG step %s: L2(div(v)) = %s, Lsup(v)=%s"%(self.iter,n_r,n_v)
120 self.iter+=1
121 if n_r <= self.vol**(1./2.-1./self.domain.getDim())*n_v*self.getTolerance():
122 if self.verbose: print "PCG terminated after %s steps."%self.iter
123 return True
124 else:
125 return False
126 def stoppingcriterium2(self,norm_r,norm_b,solver='GMRES'):
127 if self.verbose: print "%s step %s: L2(r) = %s, L2(b)*TOL=%s"%(solver,self.iter,norm_r,norm_b*self.getTolerance())
128 self.iter+=1
129 if norm_r <= norm_b*self.getTolerance():
130 if self.verbose: print "%s terminated after %s steps."%(solver,self.iter)
131 return True
132 else:
133 return False
134
135

  ViewVC Help
Powered by ViewVC 1.1.26