/[escript]/trunk/doc/examples/cookbook/example09b.py
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Annotation of /trunk/doc/examples/cookbook/example09b.py

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Revision 3195 - (hide annotations)
Wed Sep 22 00:28:04 2010 UTC (9 years, 1 month ago) by ahallam
File MIME type: text/x-python
File size: 6369 byte(s)
Shortened runtime of cookbook examples to aid testing.
1 ahallam 3089
2     ########################################################
3     #
4     # Copyright (c) 2009-2010 by University of Queensland
5     # Earth Systems Science Computational Center (ESSCC)
6     # http://www.uq.edu.au/esscc
7     #
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     __copyright__="""Copyright (c) 2009-2010 by University of Queensland
15     Earth Systems Science Computational Center (ESSCC)
16     http://www.uq.edu.au/esscc
17     Primary Business: Queensland, Australia"""
18     __license__="""Licensed under the Open Software License version 3.0
19     http://www.opensource.org/licenses/osl-3.0.php"""
20     __url__="https://launchpad.net/escript-finley"
21    
22     ############################################################FILE HEADER
23     # example09.py
24     # Antony Hallam
25     # Seismic Wave Equation Simulation using acceleration solution.
26     # 3D model with multiple layers.
27    
28     #######################################################EXTERNAL MODULES
29     from esys.escript import *
30     from esys.finley import Rectangle
31     import os
32     # smoothing operator
33     from esys.escript.pdetools import Projector, Locator
34     from esys.escript.unitsSI import *
35     import numpy as np
36 jfenwick 3148 import matplotlib
37     matplotlib.use('agg') #It's just here for automated testing
38    
39 ahallam 3089 import pylab as pl
40     import matplotlib.cm as cm
41     from esys.escript.linearPDEs import LinearPDE
42     from esys.finley import ReadMesh
43    
44     ########################################################MPI WORLD CHECK
45     if getMPISizeWorld() > 1:
46     import sys
47     print "This example will not run in an MPI world."
48     sys.exit(0)
49    
50     #################################################ESTABLISHING VARIABLES
51     # where to save output data
52     savepath = "data/example09b2"
53     meshpath = "data/example09m"
54     mkDir(savepath)
55     #Geometric and material property related variables.
56     mx = 200. # model lenght
57     my = 200. # model width
58     mz=100.0
59 ahallam 3099 step=4.0 # the element size
60 ahallam 3089 ndx = int(mx/step) # steps in x direction
61     ndy = int(my/step) # steps in y direction
62     ndz = int(mz/step)
63    
64     vel2=1800.; vel1=3000.
65     rho2=2300.; rho1=3100. #density
66     mu2=vel2**2.*rho2/4.; mu1=vel1**2.*rho1/4. #bulk modulus
67     lam2=vel2**2.*rho2/2.; lam1=vel1**2.*rho1/2. #lames constant
68    
69     # Time related variables.
70 ahallam 3195 testing=True
71     if testing:
72     print 'The testing end time is curerntly sellected this severely limits the number of time iterations.'
73     print "Try changing testing to False for more iterations."
74     tend=0.001
75     else:
76     tend=0.1 # end time
77    
78 ahallam 3089 h=0.00005 # time step
79     # data recording times
80     rtime=0.0 # first time to record
81 ahallam 3099 rtime_inc=tend/200.0 # time increment to record
82 ahallam 3089 #Check to make sure number of time steps is not too large.
83     print "Time step size= ",h, "Expected number of outputs= ",tend/h
84    
85     U0=0.1 # amplitude of point source
86     ls=500 # length of the source
87     source=np.zeros(ls,'float') # source array
88     decay1=np.zeros(ls,'float') # decay curve one
89     decay2=np.zeros(ls,'float') # decay curve two
90     time=np.zeros(ls,'float') # time values
91     g=np.log(0.01)/ls
92    
93     dfeq=50 #Dominant Frequency
94     a = 2.0 * (np.pi * dfeq)**2.0
95     t0 = 5.0 / (2.0 * np.pi * dfeq)
96     srclength = 5. * t0
97     ls = int(srclength/h)
98     print 'source length',ls
99     source=np.zeros(ls,'float') # source array
100     ampmax=0
101     for it in range(0,ls):
102     t = it*h
103     tt = t-t0
104     dum1 = np.exp(-a * tt * tt)
105     source[it] = -2. * a * tt * dum1
106     if (abs(source[it]) > ampmax):
107     ampmax = abs(source[it])
108     time[t]=t*h
109     #tdecay=decay1*decay2*U0
110     #decay1=decay1*U0; decay2=decay2*U0
111     #pl.clf();
112     #pl.plot(source)
113     #pl.plot(time,decay1);pl.plot(time,decay2);
114     #pl.plot(time,tdecay)
115     #pl.savefig(os.path.join(savepath,'source.png'))
116    
117     # will introduce a spherical source at middle left of bottom face
118     xc=[mx/2,my/2,0]
119    
120     ####################################################DOMAIN CONSTRUCTION
121     domain=ReadMesh(os.path.join(meshpath,'example09m.fly')) # create the domain
122     x=domain.getX() # get the locations of the nodes in the domain
123    
124     lam=Scalar(0,Function(domain))
125     lam.setTaggedValue("vintfa",lam1)
126     lam.setTaggedValue("vintfb",lam2)
127     mu=Scalar(0,Function(domain))
128     mu.setTaggedValue("vintfa",mu1)
129     mu.setTaggedValue("vintfb",mu2)
130     rho=Scalar(0,Function(domain))
131     rho.setTaggedValue("vintfa",rho1)
132     rho.setTaggedValue("vintfb",rho2)
133    
134     ##########################################################ESTABLISH PDE
135     mypde=LinearPDE(domain) # create pde
136     mypde.setSymmetryOn() # turn symmetry on
137     # turn lumping on for more efficient solving
138     #mypde.getSolverOptions().setSolverMethod(mypde.getSolverOptions().LUMPING)
139     kmat = kronecker(domain) # create the kronecker delta function of the domain
140     mypde.setValue(D=rho*kmat) #set the general form value D
141    
142     ############################################FIRST TIME STEPS AND SOURCE
143     # define small radius around point xc
144     src_length = 20; print "src_length = ",src_length
145     # set initial values for first two time steps with source terms
146     xb=FunctionOnBoundary(domain).getX()
147     yx=(cos(length(xb-xc)*3.1415/src_length)+1)*whereNegative(length(xb-xc)-src_length)
148     stop=Scalar(0.0,FunctionOnBoundary(domain))
149     stop.setTaggedValue("stop",1.0)
150 ahallam 3099 src_dir=numpy.array([0.,1.,0.0]) # defines direction of point source as down
151 ahallam 3089
152     mypde.setValue(y=source[0]*yx*src_dir*stop) #set the source as a function on the boundary
153     # initial value of displacement at point source is constant (U0=0.01)
154     # for first two time steps
155     u=[0.0,0.0,0.0]*wherePositive(x)
156     u_m1=u
157    
158     ####################################################ITERATION VARIABLES
159     n=0 # iteration counter
160     t=0 # time counter
161     ##############################################################ITERATION
162     while t<tend:
163     # get current stress
164     g=grad(u); stress=lam*trace(g)*kmat+mu*(g+transpose(g))#*abc
165     mypde.setValue(X=-stress) # set PDE values
166     accel = mypde.getSolution() #get PDE solution for accelleration
167     u_p1=(2.*u-u_m1)+h*h*accel #calculate displacement
168     u_p1=u_p1#*abc # apply boundary conditions
169     u_m1=u; u=u_p1 # shift values by 1
170     # save current displacement, acceleration and pressure
171     if (t >= rtime):
172     saveVTK(os.path.join(savepath,"ex09b.%05d.vtu"%n),displacement=length(u),\
173     acceleration=length(accel),tensor=stress)
174     rtime=rtime+rtime_inc #increment data save time
175     # increment loop values
176     t=t+h; n=n+1
177     if (n < ls):
178     mypde.setValue(y=source[n]*yx*src_dir*stop) #set the source as a function on the boundary
179     print n,"-th time step t ",t

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