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

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Revision 3195 - (show annotations)
Wed Sep 22 00:28:04 2010 UTC (8 years, 11 months ago) by ahallam
File MIME type: text/x-python
File size: 6369 byte(s)
Shortened runtime of cookbook examples to aid testing.
1
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 import matplotlib
37 matplotlib.use('agg') #It's just here for automated testing
38
39 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 step=4.0 # the element size
60 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 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 h=0.00005 # time step
79 # data recording times
80 rtime=0.0 # first time to record
81 rtime_inc=tend/200.0 # time increment to record
82 #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 src_dir=numpy.array([0.,1.,0.0]) # defines direction of point source as down
151
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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