/[escript]/trunk/doc/examples/cookbook/example09a.py
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Contents of /trunk/doc/examples/cookbook/example09a.py

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Revision 3195 - (show annotations)
Wed Sep 22 00:28:04 2010 UTC (9 years ago) by ahallam
File MIME type: text/x-python
File size: 6438 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/example09"
53 mkDir(savepath)
54 #Geometric and material property related variables.
55 mx = 200. # model lenght
56 my = 200. # model width
57 mz=100.0
58 step=10.0 # the element size
59 ndx = int(mx/step) # steps in x direction
60 ndy = int(my/step) # steps in y direction
61 ndz = int(mz/step)
62
63 vel2=1800.; vel1=3000.
64 rho2=2300.; rho1=3100. #density
65 mu2=vel2**2.*rho2/4.; mu1=vel1**2.*rho1/4. #bulk modulus
66 lam2=vel2**2.*rho2/2.; lam1=vel1**2.*rho1/2. #lames constant
67
68 # Time related variables.
69 testing=True
70 if testing:
71 print 'The testing end time is curerntly sellected this severely limits the number of time iterations.'
72 print "Try changing testing to False for more iterations."
73 tend=0.001
74 else:
75 tend=0.1 # end time
76
77 h=0.0001 # time step
78 # data recording times
79 rtime=0.0 # first time to record
80 rtime_inc=tend/50.0 # time increment to record
81 #Check to make sure number of time steps is not too large.
82 print "Time step size= ",h, "Expected number of outputs= ",tend/h
83
84 U0=0.1 # amplitude of point source
85 ls=500 # length of the source
86 source=np.zeros(ls,'float') # source array
87 decay1=np.zeros(ls,'float') # decay curve one
88 decay2=np.zeros(ls,'float') # decay curve two
89 time=np.zeros(ls,'float') # time values
90 g=np.log(0.01)/ls
91
92 dfeq=50 #Dominant Frequency
93 a = 2.0 * (np.pi * dfeq)**2.0
94 t0 = 5.0 / (2.0 * np.pi * dfeq)
95 srclength = 5. * t0
96 ls = int(srclength/h)
97 print 'source length',ls
98 source=np.zeros(ls,'float') # source array
99 ampmax=0
100 for it in range(0,ls):
101 t = it*h
102 tt = t-t0
103 dum1 = np.exp(-a * tt * tt)
104 source[it] = -2. * a * tt * dum1
105 if (abs(source[it]) > ampmax):
106 ampmax = abs(source[it])
107 time[t]=t*h
108 #tdecay=decay1*decay2*U0
109 #decay1=decay1*U0; decay2=decay2*U0
110 #pl.clf();
111 #pl.plot(source)
112 #pl.plot(time,decay1);pl.plot(time,decay2);
113 #pl.plot(time,tdecay)
114 #pl.savefig(os.path.join(savepath,'source.png'))
115
116 # will introduce a spherical source at middle left of bottom face
117 xc=[50,50,0]
118
119 ####################################################DOMAIN CONSTRUCTION
120 domain=ReadMesh(os.path.join(savepath,'example09m.fly')) # create the domain
121 x=domain.getX() # get the locations of the nodes in the domain
122
123 lam=Scalar(0,Function(domain))
124 lam.setTaggedValue("vintfa",lam1)
125 lam.setTaggedValue("vintfb",lam2)
126 mu=Scalar(0,Function(domain))
127 mu.setTaggedValue("vintfa",mu1)
128 mu.setTaggedValue("vintfb",mu2)
129 rho=Scalar(0,Function(domain))
130 rho.setTaggedValue("vintfa",rho1)
131 rho.setTaggedValue("vintfb",rho2)
132
133 ##########################################################ESTABLISH PDE
134 mypde=LinearPDE(domain) # create pde
135 mypde.setSymmetryOn() # turn symmetry on
136 # turn lumping on for more efficient solving
137 #mypde.getSolverOptions().setSolverMethod(mypde.getSolverOptions().LUMPING)
138 kmat = kronecker(domain) # create the kronecker delta function of the domain
139 mypde.setValue(D=rho*kmat) #set the general form value D
140
141 ############################################FIRST TIME STEPS AND SOURCE
142 # define small radius around point xc
143 src_length = 20; print "src_length = ",src_length
144 # set initial values for first two time steps with source terms
145 xb=FunctionOnBoundary(domain).getX()
146 #sy=source[0]*(cos(length(xb-xc)*3.1415/src_length)+1)*whereNegative(length(xb-src_length))
147 y=Vector(0.0,FunctionOnBoundary(domain))
148
149 src_dir=numpy.array([0.,0.,1.0]) # defines direction of point source as down
150
151 #sy=sy*src_dir
152 #sy.setTaggedValue("stop")
153 y.setTaggedValue("stop",src_dir*source[0])#)*(cos(length(xb-xc)*3.1415/src_length)+1))
154 mypde.setValue(y=y) #set the source as a function on the boundary
155 # initial value of displacement at point source is constant (U0=0.01)
156 # for first two time steps
157 u=[0.0,0.0,0.0]*wherePositive(x)
158 u_m1=u
159
160 ####################################################ITERATION VARIABLES
161 n=0 # iteration counter
162 t=0 # time counter
163 ##############################################################ITERATION
164 while t<tend:
165 # get current stress
166 g=grad(u); stress=lam*trace(g)*kmat+mu*(g+transpose(g))#*abc
167 mypde.setValue(X=-stress) # set PDE values
168 accel = mypde.getSolution() #get PDE solution for accelleration
169 u_p1=(2.*u-u_m1)+h*h*accel #calculate displacement
170 u_p1=u_p1#*abc # apply boundary conditions
171 u_m1=u; u=u_p1 # shift values by 1
172 # save current displacement, acceleration and pressure
173 if (t >= rtime):
174 saveVTK(os.path.join(savepath,"ex09.%05d.vtu"%n),displacement=length(u),\
175 acceleration=length(accel),tensor=stress)
176 rtime=rtime+rtime_inc #increment data save time
177 # increment loop values
178 t=t+h; n=n+1
179 if (n < ls):
180 y.setTaggedValue("stop",source[n]*src_dir)
181 mypde.setValue(y=y) #set the source as a function on the boundary
182 print n,"-th time step t ",t

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