/[escript]/trunk/doc/examples/cookbook/example09b.py
ViewVC logotype

Contents of /trunk/doc/examples/cookbook/example09b.py

Parent Directory Parent Directory | Revision Log Revision Log


Revision 3892 - (show annotations)
Tue Apr 10 08:57:23 2012 UTC (6 years, 9 months ago) by jfenwick
File MIME type: text/x-python
File size: 6501 byte(s)
Merged changes across from the attempt2 branch.
This version builds and passes python2 tests.
It also passes most python3 tests.



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. Layercake example.
27
28 #######################################################EXTERNAL MODULES
29 from esys.escript import *
30 from esys.finley import Rectangle
31 from esys.weipa import saveVTK
32 import os
33 # smoothing operator
34 from esys.escript.pdetools import Projector, Locator
35 from esys.escript.unitsSI import *
36 import numpy as np
37 import matplotlib
38 matplotlib.use('agg') #It's just here for automated testing
39
40 import pylab as pl
41 import matplotlib.cm as cm
42 from esys.escript.linearPDEs import LinearPDE
43 from esys.finley import ReadMesh
44
45 ########################################################MPI WORLD CHECK
46 if getMPISizeWorld() > 1:
47 import sys
48 print("This example will not run in an MPI world.")
49 sys.exit(0)
50
51 #################################################ESTABLISHING VARIABLES
52 # where to save output data
53 savepath = "data/example09b"
54 meshpath = "data/example09m"
55 mkDir(savepath)
56 #Geometric and material property related variables.
57 step=4.0 # the element size
58
59 vel=1800. #starting velocity
60 rhoc=2000. #starting density
61 nlayers=9 #number of layers in layercake model.
62
63 ####################################################TESTING SWITCH
64 testing=True
65 if testing:
66 print('The testing end time is currently selected. This severely limits the number of time iterations.')
67 print("Try changing testing to False for more iterations.")
68 tend=0.001
69 #Model Parameters
70 mx=40.
71 my=40.
72 mz=20.
73 outputs=5
74 else:
75 tend=0.1 # end time
76 #Model Parameters
77 mx=100.0 #x width of model
78 my=100.0 #y width of model
79 mz=50.0 #depth of model
80 outputs=200
81
82 ####################################################TIME RELATED VARIABLES
83 h=0.00001 # time step
84 # data recording times
85 rtime=0.0 # first time to record
86 rtime_inc=tend/outputs # time increment to record
87 #Check to make sure number of time steps is not too large.
88 print("Time step size= ",h, "Expected number of outputs= ",tend/h)
89
90 ####################################################CREATING THE SOURCE FUNCTION
91 U0=0.1 # amplitude of point source
92 ls=500 # length of the source
93 source=np.zeros(ls,'float') # source array
94 decay1=np.zeros(ls,'float') # decay curve one
95 decay2=np.zeros(ls,'float') # decay curve two
96 time=np.zeros(ls,'float') # time values
97 g=np.log(0.01)/ls
98
99 dfeq=50 #Dominant Frequency
100 a = 2.0 * (np.pi * dfeq)**2.0
101 t0 = 5.0 / (2.0 * np.pi * dfeq)
102 srclength = 5. * t0
103 ls = int(srclength/h)
104 print('source length',ls)
105 source=np.zeros(ls,'float') # source array
106 ampmax=0
107 for it in range(0,ls):
108 t = it*h
109 tt = t-t0
110 dum1 = np.exp(-a * tt * tt)
111 source[it] = -2. * a * tt * dum1
112 if (abs(source[it]) > ampmax):
113 ampmax = abs(source[it])
114 time[t]=t*h
115
116 # will introduce a spherical source at middle left of bottom face
117 xc=[mx/2,my/2,0]
118
119 ####################################################DOMAIN CONSTRUCTION
120 domain=ReadMesh(os.path.join(meshpath,'example09lc.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 mu=Scalar(0,Function(domain))
125 rho=Scalar(0,Function(domain))
126
127 #Setting parameters for each layer in the model.
128 for i in range(0,nlayers):
129 rho.setTaggedValue("volume_%d"%i,rhoc+i*100.)
130 lamc=(vel+i*100.)**2.*(rhoc+i*100.)/2.
131 muc=(vel+i*100.)**2.*(rhoc+i*100.)/4.
132 lam.setTaggedValue("volume_%d"%i,lamc)
133 mu.setTaggedValue("volume_%d"%i,muc)
134
135 ##########################################################ESTABLISH PDE
136 mypde=LinearPDE(domain) # create pde
137 mypde.setSymmetryOn() # turn symmetry on
138 # turn lumping on for more efficient solving
139 #mypde.getSolverOptions().setSolverMethod(mypde.getSolverOptions().HRZ_LUMPING)
140 kmat = kronecker(domain) # create the kronecker delta function of the domain
141 mypde.setValue(D=rho*kmat) #set the general form value D
142
143 ############################################FIRST TIME STEPS AND SOURCE
144 # define small radius around point xc
145 src_rad = 20; print("src radius= ",src_rad)
146 # set initial values for first two time steps with source terms
147 xb=FunctionOnBoundary(domain).getX()
148 yx=(cos(length(xb-xc)*3.1415/src_rad)+1)*whereNegative(length(xb-xc)-src_rad)
149 stop=Scalar(0.0,FunctionOnBoundary(domain))
150 stop.setTaggedValue("intface_0",1.0)
151 src_dir=numpy.array([0.,0.,1.0]) # defines direction of point source as down
152
153 mypde.setValue(y=source[0]*yx*src_dir*stop) #set the source as a function on the boundary
154 # initial value of displacement at point source is constant (U0=0.01)
155 # for first two time steps
156 u=[0.0,0.0,0.0]*wherePositive(x)
157 u_m1=u
158
159 ####################################################ITERATION VARIABLES
160 n=0 # iteration counter
161 t=0 # time counter
162 ##############################################################ITERATION
163 while t<tend:
164 # get current stress
165 g=grad(u); stress=lam*trace(g)*kmat+mu*(g+transpose(g))#*abc
166 mypde.setValue(X=-stress) # set PDE values
167 accel = mypde.getSolution() #get PDE solution for accelleration
168 u_p1=(2.*u-u_m1)+h*h*accel #calculate displacement
169 u_p1=u_p1#*abc # apply boundary conditions
170 u_m1=u; u=u_p1 # shift values by 1
171 # save current displacement, acceleration and pressure
172 if (t >= rtime):
173 saveVTK(os.path.join(savepath,"ex09b.%05d.vtu"%n),displacement=length(u),\
174 acceleration=length(accel),tensor=stress)
175 rtime=rtime+rtime_inc #increment data save time
176 # increment loop values
177 t=t+h; n=n+1
178 if (n < ls):
179 mypde.setValue(y=source[n]*yx*src_dir*stop) #set the source as a function on the boundary
180 print(n,"-th time step t ",t)

  ViewVC Help
Powered by ViewVC 1.1.26