python solver example

utils/solvers/python/pend.py

+#!/usr/bin/env python
+#coding=utf-8
+
+import onelab
+import math, os
+
+def exportMsh(le1,le2):
+   mshFile = open(onelab.path(__file__, "pend.msh"),'w')
+   mshFile.write('$MeshFormat\n2.2 0 8\n$EndMeshFormat\n')
+   mshFile.write('$Nodes\n3\n1 0 0 0\n2 0 %s 0\n3 0 %s 0\n$EndNodes\n' %(-le1, -le1-le2))
+   mshFile.write('$Elements\n3\n1 1 2 0 1 1 2\n2 1 2 0 1 2 3\n3 15 2 0 2 3\n$EndElements\n')
+   mshFile.close()
+
+def exportMshOpt():
+   optFile = open(onelab.path(__file__, "pend.msh.opt"),'w')
+   optFile.write('n = PostProcessing.NbViews - 1;\n')
+   optFile.write('If(n >= 0)\nView[n].ShowScale = 0;\nView[n].VectorType = 5;\n')
+   optFile.write('View[n].ExternalView = 0;\nView[n].DisplacementFactor = 1 ;\n')
+   optFile.write('View[n].PointType = 1;\nView[n].PointSize = 5;\n')
+   optFile.write('View[n].LineWidth = 2;\nEndIf\n')
+   optFile.close()
+
+def exportIter(iter,t,x1,y1,x2,y2):
+   mshFile = open(onelab.path(__file__, "pend.msh"),'a')
+   mshFile.write('$NodeData\n1\n"motion"\n1\n\t%f\n3\n\t%d\n3\n' % (t, iter))
+   mshFile.write('\t3\n\t1 0 0 0\n\t2 %f %f 0\n\t3 %f %f 0\n$EndNodeData\n' %(x1,y1,x2,y2))
+   mshFile.close()
+
+OL = onelab.client()
+
+g = 9.8	# acceleration of gravity
+m = 0.3 # mass of pendulum balls
+
+l = OL.defineNumber('Geom/Length', value=1.0, label='Arm length [m]')
+time = OL.defineNumber('Dyna/time', label='time [s]')
+dt = OL.defineNumber('Dyna/dt', value=0.001, label='time step [s]')
+tmax = OL.defineNumber('Dyna/tmax', value=20, label='max time [s]')
+refresh = OL.defineNumber('Dyna/refresh', value=0.05, label='refresh interval [s]')
+theta0 = OL.defineNumber('Init/theta', value=10, label='Initial theta angle [deg]', 
+                         attributes={'Highlight':'Pink'})
+phi0 = OL.defineNumber('Init/phi', value=180, label='Initial phi angle [deg]',
+                       attributes={'Highlight':'Pink'})
+
+# we're done if we are in the "check" phase
+if OL.action == 'check' :
+   exit(0)
+
+l1 = l;
+l2 = l;
+m1 = m;
+m2 = m;
+theta = theta0 / 180.*math.pi;
+phi = phi0 / 180.*math.pi;
+theta_dot = 0.0
+phi_dot = 0.0
+time = 0.0
+refr = 0.0
+iter = 0
+
+while (time < tmax):
+   delta = phi - theta
+   sdelta = math.sin(delta)
+   cdelta = math.cos(delta)
+   theta_dot_dot = ( m2*l1*(theta_dot**2.0)*sdelta*cdelta
+                     + m2*g*math.sin(phi)*cdelta
+                     + m2*l2*(phi_dot**2.0)*sdelta
+                     - (m1+m2)*g*math.sin(theta) )
+   theta_dot_dot /= ( (m1+m2)*l1 - m2*l1*(cdelta)**2.0 )
+   
+   phi_dot_dot = ( -m2*l2*(phi_dot**2.0)*sdelta*cdelta
+                    + (m1+m2)*(g*math.sin(theta)*cdelta
+                               - l1*(theta_dot**2.0)*sdelta
+                               - g*math.sin(phi)) )
+   phi_dot_dot /= ( (m1+m2)*l2 - m2*l2*(cdelta)**2.0 )
+   
+   theta_dot = theta_dot + theta_dot_dot*dt
+   phi_dot = phi_dot + phi_dot_dot*dt
+
+   theta = theta + theta_dot*dt
+   phi = phi + phi_dot*dt
+
+   x1 =  l1*math.sin(theta)
+   y1 = -l1*math.cos(theta)
+   x2 =  l1*math.sin(theta) + l2*math.sin(phi)
+   y2 = -l1*math.cos(theta) - l2*math.cos(phi)
+
+   time += dt
+   refr += dt
+
+   exportMshOpt()
+
+   if refr >= refresh:
+      refr = 0
+      OL.setNumber('python/Progress', value=time, min=0, max=tmax, visible=0)
+      OL.setNumber('Dyna/time', value=time)
+      OL.setNumber('Solu/phi', value=phi)
+      OL.setNumber('Solu/theta', value=theta)
+      OL.addNumberChoice('Solu/phi', phi)
+      OL.addNumberChoice('Solu/theta', theta)
+      OL.setNumber('Solu/phi_dot', value=phi_dot)
+      OL.setNumber('Solu/theta_dot', value=theta_dot)
+      OL.addNumberChoice('Solu/phi_dot', phi_dot)
+      OL.addNumberChoice('Solu/theta_dot', theta_dot)
+      OL.setString('Gmsh/Action', value='refresh')
+      if(OL.getString('python/Action') == 'stop'):
+         break;
+      exportMsh(l1, l2)
+      exportIter(iter, time, x1, y1+l1, x2, y2+l1+l2)
+      OL.mergeFile(onelab.path(__file__, 'pend.msh'))
+      iter += 1
+
+OL.setNumber('python/Progress', value=0)
+
+# comment the following lines out if you do not have gnuplot on your system
+# OL.preProcess(onelab.path(__file__,'pend.plt.ol'))
+# os.system('gnuplot pend.plt')
+
+# run a subclient
+# OL.run('subclient', './sub.py','')
+
+# A = OL.defineNumber('A', value=10)
+# B = OL.defineNumber('Group/B', value=0, min = -10, max = 10, step = 1)
+# C = OL.defineNumber('Group/C', value=2, choices = [0, 1, 2, 3], 
+#                     attributes={'Highlight':'Pink'})
+# D = OL.defineNumber('Group/D', value=3, labels = {0:'zero', 1:'un', 2:'deux', 
+#                     3:'trois'}, attributes={'Highlight':'Blue'})
+
+# UTF-8 is allowed everywhere (should be prefixed by 'u' in python 2, not 
+# required in python 3)
+# Omega = OL.getString(u'Ω', u'∫(∂φ/∂α)³dx', help=u'ask someone@universe.org',
+#                      choices = ['oui', 'non', u'peut-être'])