def run_example(with_plots=True): global exp_mod, exp_sim #Define the rhs def f(t, y): ydot = -y[0] return N.array([ydot]) #Define an Assimulo problem exp_mod = Explicit_Problem(f, y0=4) exp_mod.name = 'Simple CVode Example' #Define an explicit solver exp_sim = CVode(exp_mod) #Create a CVode solver #Sets the parameters exp_sim.iter = 'Newton' #Default 'FixedPoint' exp_sim.discr = 'BDF' #Default 'Adams' exp_sim.atol = [1e-4] #Default 1e-6 exp_sim.rtol = 1e-4 #Default 1e-6 #Simulate t1, y1 = exp_sim.simulate(5, 100) #Simulate 5 seconds t2, y2 = exp_sim.simulate(7) #Simulate 2 seconds more #Basic test nose.tools.assert_almost_equal(y2[-1], 0.00347746, 5)
def _solve_cvode(f, t, y0, args, console=False, max_steps=1000, terminate=False): """Wrapper for Assimulo's CVODE-Sundials routine """ def rhs(t, u): return f(u, t, *args) prob = Explicit_Problem(rhs, y0) sim = CVode(prob) sim.rtol = 1e-15 sim.atol = 1e-12 sim.discr = 'BDF' sim.maxord = 5 sim.maxsteps = max_steps if not console: sim.verbosity = 50 else: sim.report_continuously = True t_end = t[-1] steps = len(t) try: print t_end, steps t, x = sim.simulate(t_end, steps) except CVodeError, e: raise ValueError("Something broke in CVode: %r" % e) return None, False
def run_example(with_plots=True): global exp_mod, exp_sim #Define the rhs def f(t,y): ydot = -y[0] return N.array([ydot]) #Define an Assimulo problem exp_mod = Explicit_Problem(f, y0=4) exp_mod.name = 'Simple CVode Example' #Define an explicit solver exp_sim = CVode(exp_mod) #Create a CVode solver #Sets the parameters exp_sim.iter = 'Newton' #Default 'FixedPoint' exp_sim.discr = 'BDF' #Default 'Adams' exp_sim.atol = [1e-4] #Default 1e-6 exp_sim.rtol = 1e-4 #Default 1e-6 #Simulate t1, y1 = exp_sim.simulate(5,100) #Simulate 5 seconds t2, y2 = exp_sim.simulate(7) #Simulate 2 seconds more #Basic test nose.tools.assert_almost_equal(y2[-1], 0.00347746, 5)
def run_example(with_plots=True): """ This is the same example from the Sundials package (cvsRoberts_FSA_dns.c) This simple example problem for CVode, due to Robertson, is from chemical kinetics, and consists of the following three equations:: dy1/dt = -p1*y1 + p2*y2*y3 dy2/dt = p1*y1 - p2*y2*y3 - p3*y2**2 dy3/dt = p3*(y2)^2 """ def f(t, y, p): yd_0 = -p[0]*y[0]+p[1]*y[1]*y[2] yd_1 = p[0]*y[0]-p[1]*y[1]*y[2]-p[2]*y[1]**2 yd_2 = p[2]*y[1]**2 return N.array([yd_0,yd_1,yd_2]) #The initial conditions y0 = [1.0,0.0,0.0] #Initial conditions for y #Create an Assimulo explicit problem exp_mod = Explicit_Problem(f,y0) #Sets the options to the problem exp_mod.p0 = [0.040, 1.0e4, 3.0e7] #Initial conditions for parameters exp_mod.pbar = [0.040, 1.0e4, 3.0e7] #Create an Assimulo explicit solver (CVode) exp_sim = CVode(exp_mod) #Sets the paramters exp_sim.iter = 'Newton' exp_sim.discr = 'BDF' exp_sim.rtol = 1.e-4 exp_sim.atol = N.array([1.0e-8, 1.0e-14, 1.0e-6]) exp_sim.sensmethod = 'SIMULTANEOUS' #Defines the sensitvity method used exp_sim.suppress_sens = False #Dont suppress the sensitivity variables in the error test. exp_sim.continuous_output = True #Simulate t, y = exp_sim.simulate(4,400) #Simulate 4 seconds with 400 communication points #Basic test nose.tools.assert_almost_equal(y[-1][0], 9.05518032e-01, 4) nose.tools.assert_almost_equal(y[-1][1], 2.24046805e-05, 4) nose.tools.assert_almost_equal(y[-1][2], 9.44595637e-02, 4) nose.tools.assert_almost_equal(exp_sim.p_sol[0][-1][0], -1.8761, 2) #Values taken from the example in Sundials nose.tools.assert_almost_equal(exp_sim.p_sol[1][-1][0], 2.9614e-06, 8) nose.tools.assert_almost_equal(exp_sim.p_sol[2][-1][0], -4.9334e-10, 12) #Plot if with_plots: P.plot(t, y) P.show()
def _setup_sim(self, **kwargs): """ Create a simulation interface to Assimulo using CVODE, given a problem definition """ # Create Assimulo interface sim = CVode(self.prob) sim.discr = 'BDF' sim.maxord = 5 # Setup some default arguments for the ODE solver, or override # if available. This is very hackish, but it's fine for now while # the number of anticipated tuning knobs is small. if 'maxh' in kwargs: sim.maxh = kwargs['maxh'] else: sim.maxh = np.min([0.1, self.output_dt]) if 'minh' in kwargs: sim.minh = kwargs['minh'] # else: sim.minh = 0.001 if "iter" in kwargs: sim.iter = kwargs['iter'] else: sim.iter = 'Newton' if "linear_solver" in kwargs: sim.linear_solver = kwargs['linear_solver'] if "max_steps" in kwargs: # DIFFERENT NAME!!!! sim.maxsteps = kwargs['max_steps'] else: sim.maxsteps = 1000 if "time_limit" in kwargs: sim.time_limit = kwargs['time_limit'] sim.report_continuously = True else: sim.time_limit = 0.0 # Don't save the [t_-, t_+] around events sim.store_event_points = False # Setup tolerances nr = self.args[0] sim.rtol = state_rtol sim.atol = state_atol + [1e-12]*nr if not self.console: sim.verbosity = 50 else: sim.verbosity = 40 # sim.report_continuously = False # Save the Assimulo interface return sim
def _setup_sim(self, **kwargs): """ Create a simulation interface to Assimulo using CVODE, given a problem definition """ # Create Assimulo interface sim = CVode(self.prob) sim.discr = 'BDF' sim.maxord = 5 # Setup some default arguments for the ODE solver, or override # if available. This is very hackish, but it's fine for now while # the number of anticipated tuning knobs is small. if 'maxh' in kwargs: sim.maxh = kwargs['maxh'] else: sim.maxh = np.min([0.1, self.output_dt]) if 'minh' in kwargs: sim.minh = kwargs['minh'] # else: sim.minh = 0.001 if "iter" in kwargs: sim.iter = kwargs['iter'] else: sim.iter = 'Newton' if "linear_solver" in kwargs: sim.linear_solver = kwargs['linear_solver'] if "max_steps" in kwargs: # DIFFERENT NAME!!!! sim.maxsteps = kwargs['max_steps'] else: sim.maxsteps = 1000 if "time_limit" in kwargs: sim.time_limit = kwargs['time_limit'] sim.report_continuously = True else: sim.time_limit = 0.0 # Don't save the [t_-, t_+] around events sim.store_event_points = False # Setup tolerances nr = self.args[0] sim.rtol = state_rtol sim.atol = state_atol + [1e-12] * nr if not self.console: sim.verbosity = 50 else: sim.verbosity = 40 # sim.report_continuously = False # Save the Assimulo interface return sim
def run_example(with_plots=True): #Defines the rhs def f(t, y): yd_0 = y[1] yd_1 = -9.82 return N.array([yd_0, yd_1]) #Defines the jacobian*vector product def jacv(t, y, fy, v): j = N.array([[0, 1.], [0, 0]]) return N.dot(j, v) y0 = [1.0, 0.0] #Initial conditions #Defines an Assimulo explicit problem exp_mod = Explicit_Problem(f, y0) exp_mod.jacv = jacv #Sets the jacobian exp_mod.name = 'Example using the Jacobian Vector product' exp_sim = CVode(exp_mod) #Create a CVode solver #Set the parameters exp_sim.iter = 'Newton' #Default 'FixedPoint' exp_sim.discr = 'BDF' #Default 'Adams' exp_sim.atol = 1e-5 #Default 1e-6 exp_sim.rtol = 1e-5 #Default 1e-6 exp_sim.linear_solver = 'SPGMR' #Change linear solver #exp_sim.options["usejac"] = False #Simulate t, y = exp_sim.simulate( 5, 1000) #Simulate 5 seconds with 1000 communication points #Basic tests nose.tools.assert_almost_equal(y[-1][0], -121.75000000, 4) nose.tools.assert_almost_equal(y[-1][1], -49.100000000) #Plot if with_plots: P.plot(t, y) P.show()
def run_example(with_plots=True): global t, y #Defines the rhs def f(t, y): yd_0 = y[1] yd_1 = -9.82 #print y, yd_0, yd_1 return N.array([yd_0, yd_1]) #Defines the jacobian def jac(t, y): j = N.array([[0, 1.], [0, 0]]) return j #Defines an Assimulo explicit problem y0 = [1.0, 0.0] #Initial conditions exp_mod = Explicit_Problem(f, y0) exp_mod.jac = jac #Sets the jacobian exp_mod.name = 'Example using Jacobian' exp_sim = CVode(exp_mod) #Create a CVode solver #Set the parameters exp_sim.iter = 'Newton' #Default 'FixedPoint' exp_sim.discr = 'BDF' #Default 'Adams' exp_sim.atol = 1e-5 #Default 1e-6 exp_sim.rtol = 1e-5 #Default 1e-6 #Simulate t, y = exp_sim.simulate( 5, 1000) #Simulate 5 seconds with 1000 communication points #Basic tests nose.tools.assert_almost_equal(y[-1][0], -121.75000000, 4) nose.tools.assert_almost_equal(y[-1][1], -49.100000000) #Plot if with_plots: P.plot(t, y, linestyle="dashed", marker="o") #Plot the solution P.show()
def run_example(with_plots=True): #Defines the rhs def f(t,y): yd_0 = y[1] yd_1 = -9.82 return N.array([yd_0,yd_1]) #Defines the jacobian*vector product def jacv(t,y,fy,v): j = N.array([[0,1.],[0,0]]) return N.dot(j,v) y0 = [1.0,0.0] #Initial conditions #Defines an Assimulo explicit problem exp_mod = Explicit_Problem(f,y0) exp_mod.jacv = jacv #Sets the jacobian exp_mod.name = 'Example using the Jacobian Vector product' exp_sim = CVode(exp_mod) #Create a CVode solver #Set the parameters exp_sim.iter = 'Newton' #Default 'FixedPoint' exp_sim.discr = 'BDF' #Default 'Adams' exp_sim.atol = 1e-5 #Default 1e-6 exp_sim.rtol = 1e-5 #Default 1e-6 exp_sim.linear_solver = 'SPGMR' #Change linear solver #exp_sim.options["usejac"] = False #Simulate t, y = exp_sim.simulate(5, 1000) #Simulate 5 seconds with 1000 communication points #Basic tests nose.tools.assert_almost_equal(y[-1][0],-121.75000000,4) nose.tools.assert_almost_equal(y[-1][1],-49.100000000) #Plot if with_plots: P.plot(t,y) P.show()
def run_example(with_plots=True): global t,y #Defines the rhs def f(t,y): yd_0 = y[1] yd_1 = -9.82 #print y, yd_0, yd_1 return N.array([yd_0,yd_1]) #Defines the jacobian def jac(t,y): j = N.array([[0,1.],[0,0]]) return j #Defines an Assimulo explicit problem y0 = [1.0,0.0] #Initial conditions exp_mod = Explicit_Problem(f,y0) exp_mod.jac = jac #Sets the jacobian exp_mod.name = 'Example using Jacobian' exp_sim = CVode(exp_mod) #Create a CVode solver #Set the parameters exp_sim.iter = 'Newton' #Default 'FixedPoint' exp_sim.discr = 'BDF' #Default 'Adams' exp_sim.atol = 1e-5 #Default 1e-6 exp_sim.rtol = 1e-5 #Default 1e-6 #Simulate t, y = exp_sim.simulate(5, 1000) #Simulate 5 seconds with 1000 communication points #Basic tests nose.tools.assert_almost_equal(y[-1][0],-121.75000000,4) nose.tools.assert_almost_equal(y[-1][1],-49.100000000) #Plot if with_plots: P.plot(t,y,linestyle="dashed",marker="o") #Plot the solution P.show()
def create_model(): def pendulum(t, X, sw): """ The ODE to be simulated. The parameter sw should be fixed during the simulation and only be changed during the event handling. """ #X = X.copy() g = 9.81 x = X[0] vx = X[2] vy = X[3] return np.array([vx, vy, -(np.pi**2)*x, -g, 1.0]) def state_events(t, X, sw): """ This is our function that keep track of our events, when the sign of any of the events has changed, we have an event. """ x = X[0] y = X[1] return [x - y] #return np.array([x - y]) def handle_event(solver, event_info): """ Event handling. This functions is called when Assimulo finds an event as specified by the event functions. """ state_info = event_info[0] #We are only interested in state events info if state_info[0] != 0: #Check if the first event function have been triggered if solver.sw[0]: #If the switch is True the pendulum bounces X = solver.y X[1] = X[0] + 1e-3 X[3] = 0.9*(X[2] - X[3]) #solver.sw[0] = not solver.sw[0] #Change event function #Initial values phi = 1.0241592; Y0 = -13.0666666; A = 2.0003417; w = np.pi y0 = [A*np.sin(phi), 1+A*np.sin(phi), A*w*np.cos(phi), Y0 - A*w*np.cos(phi)-1, 0] #Initial states t0 = 0.0 #Initial time switches0 = [True] #Initial switches #Create an Assimulo Problem mod = Explicit_Problem(pendulum, y0, t0, sw0=switches0) mod.state_events = state_events #Sets the state events to the problem mod.handle_event = handle_event #Sets the event handling to the problem mod.name = 'Bouncing Ball on Sonusoidal Platform' #Sets the name of the problem #Create an Assimulo solver (CVode) sim = CVode(mod) #sim = LSODAR(mod) sim.options['verbosity'] = 40 #Specifies options sim.discr = 'Adams' #Sets the discretization method sim.iter = 'FixedPoint' #Sets the iteration method sim.rtol = 1.e-8 #Sets the relative tolerance sim.atol = 1.e-6 #Sets the absolute tolerance return sim
def run_example(with_plots=True): """ This example show how to use Assimulo and CVode for simulating sensitivities for initial conditions.:: dy1/dt = -(k01+k21+k31)*y1 + k12*y2 + k13*y3 + b1 dy2/dt = k21*y1 - (k02+k12)*y2 dy3/dt = k31*y1 - k13*y3 y1(0) = p1, y2(0) = p2, y3(0) = p3 p1=p2=p3 = 0 See http://sundials.2283335.n4.nabble.com/Forward-sensitivities-for-initial-conditions-td3239724.html """ def f(t, y, p): y1,y2,y3 = y k01 = 0.0211 k02 = 0.0162 k21 = 0.0111 k12 = 0.0124 k31 = 0.0039 k13 = 0.000035 b1 = 49.3 yd_0 = -(k01+k21+k31)*y1+k12*y2+k13*y3+b1 yd_1 = k21*y1-(k02+k12)*y2 yd_2 = k31*y1-k13*y3 return N.array([yd_0,yd_1,yd_2]) #The initial conditions y0 = [0.0,0.0,0.0] #Initial conditions for y p0 = [0.0, 0.0, 0.0] #Initial conditions for parameters yS0 = N.array([[1,0,0],[0,1,0],[0,0,1.]]) #Create an Assimulo explicit problem exp_mod = Explicit_Problem(f, y0, p0=p0) #Sets the options to the problem exp_mod.yS0 = yS0 #Create an Assimulo explicit solver (CVode) exp_sim = CVode(exp_mod) #Sets the paramters exp_sim.iter = 'Newton' exp_sim.discr = 'BDF' exp_sim.rtol = 1e-7 exp_sim.atol = 1e-6 exp_sim.pbar = [1,1,1] #pbar is used to estimate the tolerances for the parameters exp_sim.continuous_output = True #Need to be able to store the result using the interpolate methods exp_sim.sensmethod = 'SIMULTANEOUS' #Defines the sensitvity method used exp_sim.suppress_sens = False #Dont suppress the sensitivity variables in the error test. #Simulate t, y = exp_sim.simulate(400) #Simulate 400 seconds #Basic test nose.tools.assert_almost_equal(y[-1][0], 1577.6552477, 5) nose.tools.assert_almost_equal(y[-1][1], 611.9574565, 5) nose.tools.assert_almost_equal(y[-1][2], 2215.88563217, 5) nose.tools.assert_almost_equal(exp_sim.p_sol[0][1][0], 1.0) #Plot if with_plots: P.figure(1) P.subplot(221) P.plot(t, N.array(exp_sim.p_sol[0])[:,0], t, N.array(exp_sim.p_sol[0])[:,1], t, N.array(exp_sim.p_sol[0])[:,2]) P.title("Parameter p1") P.legend(("p1/dy1","p1/dy2","p1/dy3")) P.subplot(222) P.plot(t, N.array(exp_sim.p_sol[1])[:,0], t, N.array(exp_sim.p_sol[1])[:,1], t, N.array(exp_sim.p_sol[1])[:,2]) P.title("Parameter p2") P.legend(("p2/dy1","p2/dy2","p2/dy3")) P.subplot(223) P.plot(t, N.array(exp_sim.p_sol[2])[:,0], t, N.array(exp_sim.p_sol[2])[:,1], t, N.array(exp_sim.p_sol[2])[:,2]) P.title("Parameter p3") P.legend(("p3/dy1","p3/dy2","p3/dy3")) P.subplot(224) P.plot(t, y) P.show()
def run_example(): def pendulum(t,y,sw): """ The ODE to be simulated. The parameter sw should be fixed during the simulation and only be changed during the event handling. """ l=1.0 g=9.81 yd_0 = y[1] yd_1 = -g/l*N.sin(y[0]) return N.array([yd_0, yd_1]) def state_events(t,y,sw): """ This is our function that keep track of our events, when the sign of any of the events has changed, we have an event. """ if sw[0]: e_0 = y[0]+N.pi/4. else: e_0 = y[0] return N.array([e_0]) def handle_event(solver, event_info): """ Event handling. This functions is called when Assimulo finds an event as specified by the event functions. """ state_info = event_info[0] #We are only interested in state events info if state_info[0] != 0: #Check if the first event function have been triggered if solver.sw[0]: #If the switch is True the pendulum bounces solver.y[1] = -0.9*solver.y[1] #Change the velocity and lose energy solver.sw[0] = not solver.sw[0] #Change event function #Initial values y0 = [N.pi/2.0, 0.0] #Initial states t0 = 0.0 #Initial time switches0 = [True] #Initial switches #Create an Assimulo Problem mod = Explicit_Problem(pendulum, y0, t0, sw0=switches0) mod.state_events = state_events #Sets the state events to the problem mod.handle_event = handle_event #Sets the event handling to the problem mod.name = 'Pendulum with events' #Sets the name of the problem #Create an Assimulo solver (CVode) sim = CVode(mod) #Specifies options sim.discr = 'Adams' #Sets the discretization method sim.iter = 'FixedPoint' #Sets the iteration method sim.rtol = 1.e-8 #Sets the relative tolerance sim.atol = 1.e-6 #Sets the absolute tolerance #Simulation ncp = 200 #Number of communication points tfinal = 10.0 #Final time t,y = sim.simulate(tfinal, ncp) #Simulate #Print event information sim.print_event_data() #Plot P.plot(t,y) P.show()
def integration_assimulo(self, **kwargs): """ Perform time integration for ODEs with the assimulo package """ assert self.set_time_setting == 1, 'Time discretization must be specified first' if self.tclose > 0: close = True else: close = False # Control vector self.U = interpolate(self.boundary_cntrl_space, self.Vb).vector()[self.bndr_i_b] if self.discontinous_boundary_values == 1: self.U[self.Corner_indices] = self.U[self.Corner_indices]/2 # Definition of the sparse solver for the ODE rhs function to # be defined next #my_solver = factorized(csc_matrix(self.M)) my_solver = factorized(self.M) #my_jac_o = csr_matrix(my_solver(self.J @ self.Q)) #my_jac_c = csr_matrix(my_solver((self.J - self.R) @ self.Q)) # Definition of the rhs function required in assimulo def rhs(t,y): """ Definition of the rhs function required in the ODE part of assimulo """ if close: if t < self.tclose: z = self.my_mult(self.J, self.my_mult(self.Q,y)) + self.my_mult(self.Bext,self.U* self.boundary_cntrl_time(t,self.tclose)) else: z = self.my_mult((self.J - self.R), self.my_mult(self.Q,y)) else: z = self.my_mult(self.J, self.my_mult(self.Q,y)) + self.my_mult(self.Bext,self.U* self.boundary_cntrl_time(t,self.tclose)) return my_solver(z) def jacobian(t,y): """ Jacobian related to the ODE formulation """ if close: if t < self.tclose: my_jac = my_jac_o else: my_jac = my_jac_c else: my_jac = my_jac_o return my_jac def jacv(t,y,fy,v): """ Jacobian matrix-vector product related to the ODE formulation """ if close: if t < self.tclose: z = self.my_mult(self.J, self.my_mult(self.Q,v) ) else: z = self.my_mult((self.J - self.R), self.my_mult(self.Q,v)) else: z = self.my_mult(self.J, self.my_mult(self.Q,v)) return my_solver(z) print('ODE Integration using assimulo built-in functions:') # # https://jmodelica.org/assimulo/_modules/assimulo/examples/cvode_with_preconditioning.html#run_example # model = Explicit_Problem(rhs,self.A0,self.tinit) #model.jac = jacobian model.jacv = jacv sim = CVode(model,**kwargs) sim.atol = 1e-3 sim.rtol = 1e-3 sim.linear_solver = 'SPGMR' sim.maxord = 3 #sim.usejac = True #sim = RungeKutta34(model,**kwargs) time_span, ODE_solution = sim.simulate(self.tfinal) A_ode = ODE_solution.transpose() # Hamiltonian self.Nt = A_ode.shape[1] self.tspan = np.array(time_span) Ham_ode = np.zeros(self.Nt) for k in range(self.Nt): #Ham_ode[k] = 1/2 * A_ode[:,k] @ self.M @ self.Q @ A_ode[:,k] Ham_ode[k] = 1/2 * self.my_mult(A_ode[:,k].T, \ self.my_mult(self.M, self.my_mult(self.Q, A_ode[:,k]))) # Get q variables Aq_ode = A_ode[:self.Nq,:] # Get p variables Ap_ode = A_ode[self.Nq:,:] # Get Deformation Rho = np.zeros(self.Np) for i in range(self.Np): Rho[i] = self.rho(self.coord_p[i]) W_ode = np.zeros((self.Np,self.Nt)) theta = .5 for k in range(self.Nt-1): W_ode[:,k+1] = W_ode[:,k] + self.dt * 1/Rho[:] * ( theta * Ap_ode[:,k+1] + (1-theta) * Ap_ode[:,k] ) self.Ham_ode = Ham_ode return Aq_ode, Ap_ode, Ham_ode, W_ode, np.array(time_span)
def run_example(with_plots=True): def curl(v): return array([[0, v[2], -v[1]], [-v[2], 0, v[0]], [v[1], -v[0], 0]]) #Defines the rhs def f(t, u): """ Simulations for the Gyro (Heavy Top) example in Celledoni/Safstrom: Journal of Physics A, Vol 39, 5463-5478, 2006 """ I1 = 1000. I2 = 5000. I3 = 6000. u0 = [0, 0, 1.] pi = u[0:3] Q = (u[3:12]).reshape((3, 3)) Qu0 = dot(Q, u0) f = array([Qu0[1], -Qu0[0], 0.]) f = 0 omega = array([pi[0] / I1, pi[1] / I2, pi[2] / I3]) pid = dot(curl(omega), pi) + f Qd = dot(curl(omega), Q) return hstack([pid, Qd.reshape((9, ))]) def energi(state): energi = [] for st in state: Q = (st[3:12]).reshape((3, 3)) pi = st[0:3] u0 = [0, 0, 1.] Qu0 = dot(Q, u0) V = Qu0[2] # potential energy T = 0.5 * (pi[0]**2 / 1000. + pi[1]**2 / 5000. + pi[2]**2 / 6000.) energi.append([T]) return energi #Initial conditions y0 = hstack([[1000. * 10, 5000. * 10, 6000 * 10], eye(3).reshape((9, ))]) #Create an Assimulo explicit problem gyro_mod = Explicit_Problem(f, y0) #Create an Assimulo explicit solver (CVode) gyro_sim = CVode(gyro_mod) #Sets the parameters gyro_sim.discr = 'BDF' gyro_sim.iter = 'Newton' gyro_sim.maxord = 2 #Sets the maxorder gyro_sim.atol = 1.e-10 gyro_sim.rtol = 1.e-10 #Simulate t, y = gyro_sim.simulate(0.1) #Basic tests nose.tools.assert_almost_equal(y[-1][0], 692.800241862) nose.tools.assert_almost_equal(y[-1][8], 7.08468221e-1) #Plot if with_plots: P.plot(t, y) P.show()
def run_example(with_plots=True): """ This example show how to use Assimulo and CVode for simulating sensitivities for initial conditions.:: dy1/dt = -(k01+k21+k31)*y1 + k12*y2 + k13*y3 + b1 dy2/dt = k21*y1 - (k02+k12)*y2 dy3/dt = k31*y1 - k13*y3 y1(0) = p1, y2(0) = p2, y3(0) = p3 p1=p2=p3 = 0 See http://sundials.2283335.n4.nabble.com/Forward-sensitivities-for-initial-conditions-td3239724.html """ def f(t, y, p): y1, y2, y3 = y k01 = 0.0211 k02 = 0.0162 k21 = 0.0111 k12 = 0.0124 k31 = 0.0039 k13 = 0.000035 b1 = 49.3 yd_0 = -(k01 + k21 + k31) * y1 + k12 * y2 + k13 * y3 + b1 yd_1 = k21 * y1 - (k02 + k12) * y2 yd_2 = k31 * y1 - k13 * y3 return N.array([yd_0, yd_1, yd_2]) #The initial conditions y0 = [0.0, 0.0, 0.0] #Initial conditions for y p0 = [0.0, 0.0, 0.0] #Initial conditions for parameters yS0 = N.array([[1, 0, 0], [0, 1, 0], [0, 0, 1.]]) #Create an Assimulo explicit problem exp_mod = Explicit_Problem(f, y0, p0=p0) #Sets the options to the problem exp_mod.yS0 = yS0 #Create an Assimulo explicit solver (CVode) exp_sim = CVode(exp_mod) #Sets the paramters exp_sim.iter = 'Newton' exp_sim.discr = 'BDF' exp_sim.rtol = 1e-7 exp_sim.atol = 1e-6 exp_sim.pbar = [ 1, 1, 1 ] #pbar is used to estimate the tolerances for the parameters exp_sim.continuous_output = True #Need to be able to store the result using the interpolate methods exp_sim.sensmethod = 'SIMULTANEOUS' #Defines the sensitvity method used exp_sim.suppress_sens = False #Dont suppress the sensitivity variables in the error test. #Simulate t, y = exp_sim.simulate(400) #Simulate 400 seconds #Basic test nose.tools.assert_almost_equal(y[-1][0], 1577.6552477, 5) nose.tools.assert_almost_equal(y[-1][1], 611.9574565, 5) nose.tools.assert_almost_equal(y[-1][2], 2215.88563217, 5) nose.tools.assert_almost_equal(exp_sim.p_sol[0][1][0], 1.0) #Plot if with_plots: P.figure(1) P.subplot(221) P.plot(t, N.array(exp_sim.p_sol[0])[:, 0], t, N.array(exp_sim.p_sol[0])[:, 1], t, N.array(exp_sim.p_sol[0])[:, 2]) P.title("Parameter p1") P.legend(("p1/dy1", "p1/dy2", "p1/dy3")) P.subplot(222) P.plot(t, N.array(exp_sim.p_sol[1])[:, 0], t, N.array(exp_sim.p_sol[1])[:, 1], t, N.array(exp_sim.p_sol[1])[:, 2]) P.title("Parameter p2") P.legend(("p2/dy1", "p2/dy2", "p2/dy3")) P.subplot(223) P.plot(t, N.array(exp_sim.p_sol[2])[:, 0], t, N.array(exp_sim.p_sol[2])[:, 1], t, N.array(exp_sim.p_sol[2])[:, 2]) P.title("Parameter p3") P.legend(("p3/dy1", "p3/dy2", "p3/dy3")) P.subplot(224) P.plot(t, y) P.show()
def run_example(with_plots=True): """ This is the same example from the Sundials package (cvsRoberts_FSA_dns.c) This simple example problem for CVode, due to Robertson, is from chemical kinetics, and consists of the following three equations:: dy1/dt = -p1*y1 + p2*y2*y3 dy2/dt = p1*y1 - p2*y2*y3 - p3*y2**2 dy3/dt = p3*(y2)^2 """ def f(t, y, p): yd_0 = -p[0] * y[0] + p[1] * y[1] * y[2] yd_1 = p[0] * y[0] - p[1] * y[1] * y[2] - p[2] * y[1]**2 yd_2 = p[2] * y[1]**2 return N.array([yd_0, yd_1, yd_2]) #The initial conditions y0 = [1.0, 0.0, 0.0] #Initial conditions for y #Create an Assimulo explicit problem exp_mod = Explicit_Problem(f, y0) #Sets the options to the problem exp_mod.p0 = [0.040, 1.0e4, 3.0e7] #Initial conditions for parameters exp_mod.pbar = [0.040, 1.0e4, 3.0e7] #Create an Assimulo explicit solver (CVode) exp_sim = CVode(exp_mod) #Sets the paramters exp_sim.iter = 'Newton' exp_sim.discr = 'BDF' exp_sim.rtol = 1.e-4 exp_sim.atol = N.array([1.0e-8, 1.0e-14, 1.0e-6]) exp_sim.sensmethod = 'SIMULTANEOUS' #Defines the sensitvity method used exp_sim.suppress_sens = False #Dont suppress the sensitivity variables in the error test. exp_sim.continuous_output = True #Simulate t, y = exp_sim.simulate( 4, 400) #Simulate 4 seconds with 400 communication points #Basic test nose.tools.assert_almost_equal(y[-1][0], 9.05518032e-01, 4) nose.tools.assert_almost_equal(y[-1][1], 2.24046805e-05, 4) nose.tools.assert_almost_equal(y[-1][2], 9.44595637e-02, 4) nose.tools.assert_almost_equal( exp_sim.p_sol[0][-1][0], -1.8761, 2) #Values taken from the example in Sundials nose.tools.assert_almost_equal(exp_sim.p_sol[1][-1][0], 2.9614e-06, 8) nose.tools.assert_almost_equal(exp_sim.p_sol[2][-1][0], -4.9334e-10, 12) #Plot if with_plots: P.plot(t, y) P.show()
def run_example(with_plots=True): def curl(v): return array([[0,v[2],-v[1]],[-v[2],0,v[0]],[v[1],-v[0],0]]) #Defines the rhs def f(t,u): """ Simulations for the Gyro (Heavy Top) example in Celledoni/Safstrom: Journal of Physics A, Vol 39, 5463-5478, 2006 """ I1=1000. I2=5000. I3=6000. u0=[0,0,1.] pi=u[0:3] Q=(u[3:12]).reshape((3,3)) Qu0=dot(Q,u0) f=array([Qu0[1],-Qu0[0],0.]) f=0 omega=array([pi[0]/I1,pi[1]/I2,pi[2]/I3]) pid=dot(curl(omega),pi)+f Qd=dot(curl(omega),Q) return hstack([pid,Qd.reshape((9,))]) def energi(state): energi=[] for st in state: Q=(st[3:12]).reshape((3,3)) pi=st[0:3] u0=[0,0,1.] Qu0=dot(Q,u0) V=Qu0[2] # potential energy T=0.5*(pi[0]**2/1000.+pi[1]**2/5000.+pi[2]**2/6000.) energi.append([T]) return energi #Initial conditions y0=hstack([[1000.*10,5000.*10,6000*10],eye(3).reshape((9,))]) #Create an Assimulo explicit problem gyro_mod = Explicit_Problem(f,y0) #Create an Assimulo explicit solver (CVode) gyro_sim=CVode(gyro_mod) #Sets the parameters gyro_sim.discr='BDF' gyro_sim.iter='Newton' gyro_sim.maxord=2 #Sets the maxorder gyro_sim.atol=1.e-10 gyro_sim.rtol=1.e-10 #Simulate t, y = gyro_sim.simulate(0.1) #Basic tests nose.tools.assert_almost_equal(y[-1][0],692.800241862) nose.tools.assert_almost_equal(y[-1][8],7.08468221e-1) #Plot if with_plots: P.plot(t,y) P.show()
def integration_assimulo(self, **kwargs): """ Perform time integration for ODEs with the assimulo package """ assert self.set_time_setting == 1, 'Time discretization must be specified first' if self.tclose > 0: close = True else: close = False # Control vector self.U = interpolate(self.boundary_cntrl_space, self.Vb).vector()[self.bndr_i_b] if self.discontinous_boundary_values == 1: self.U[self.Corner_indices] = self.U[self.Corner_indices]/2 # Definition of the sparse solver for the ODE rhs function to # be defined next my_solver = factorized(csc_matrix(self.Mp_rho_Cv)) C = self.A if self.sparse == 1: my_jac_o = csr_matrix(my_solver(C.toarray())) else: my_jac_o = my_solver(C) # Definition of the rhs function required in assimulo def rhs(t,y): """ Definition of the rhs function required in the ODE part of assimulo """ z = self.my_mult(self.A, y) + self.my_mult(self.Bext,self.U* self.boundary_cntrl_time(t,self.tclose)) return my_solver(z) #z = np.zeros(shape=y.shape[:]) #z[0:self.Np] = self.my_mult(self.Mp, yd[0:self.Np]) - self.my_mult(D, y[self.Np+self.Nq:self.Np+2*self.Nq]) #z[self.Np:self.Np+self.Nq] = self.my_mult(self.Mq, y[self.Np:self.Np+self.Nq]) + self.my_mult(D.T, y[0:self.Np]) - self.my_mult(self.Bp, self.U* self.boundary_cntrl_time(t,self.tclose)) #z[self.Np+self.Nq:self.Np+2*self.Nq] = self.my_mult(self.Mq, y[self.Np+self.Nq:self.Np+2*self.Nq]) - self.my_mult(self.L,y[self.Np:self.Np+self.Nq]) #return z def jacobian(t,y): """ Jacobian related to the ODE formulation """ my_jac = my_jac_o return my_jac def jacv(t,y,fy,v): """ Jacobian matrix-vector product related to the ODE formulation """ return None print('ODE Integration using assimulo built-in functions:') # # https://jmodelica.org/assimulo/_modules/assimulo/examples/cvode_with_preconditioning.html#run_example # model = Explicit_Problem(rhs,self.Tp0,self.tinit) sim = CVode(model,**kwargs) sim.atol = 1e-3 sim.rtol = 1e-3 sim.linear_solver = 'SPGMR' sim.maxord = 3 #sim.usejac = True #sim = RungeKutta34(model,**kwargs) time_span, ODE_solution = sim.simulate(self.tfinal) A_ode = ODE_solution.transpose() # Hamiltonian self.Nt = A_ode.shape[1] self.tspan = np.array(time_span) Ham_ode = np.zeros(self.Nt) for k in range(self.Nt): Ham_ode[k] = 1/2 * self.my_mult(A_ode[:,k].T, \ self.my_mult(self.Mp_rho_Cv, A_ode[:,k])) self.Ham_ode = Ham_ode return Ham_ode, np.array(time_span)
def create_model(): def pendulum(t, X, sw): """ The ODE to be simulated. The parameter sw should be fixed during the simulation and only be changed during the event handling. """ #X = X.copy() g = 9.81 x = X[0] vx = X[2] vy = X[3] return np.array([vx, vy, -(np.pi**2) * x, -g, 1.0]) def state_events(t, X, sw): """ This is our function that keep track of our events, when the sign of any of the events has changed, we have an event. """ x = X[0] y = X[1] return [x - y] #return np.array([x - y]) def handle_event(solver, event_info): """ Event handling. This functions is called when Assimulo finds an event as specified by the event functions. """ state_info = event_info[ 0] #We are only interested in state events info if state_info[ 0] != 0: #Check if the first event function have been triggered if solver.sw[0]: #If the switch is True the pendulum bounces X = solver.y X[1] = X[0] + 1e-3 X[3] = 0.9 * (X[2] - X[3]) #solver.sw[0] = not solver.sw[0] #Change event function #Initial values phi = 1.0241592 Y0 = -13.0666666 A = 2.0003417 w = np.pi y0 = [ A * np.sin(phi), 1 + A * np.sin(phi), A * w * np.cos(phi), Y0 - A * w * np.cos(phi) - 1, 0 ] #Initial states t0 = 0.0 #Initial time switches0 = [True] #Initial switches #Create an Assimulo Problem mod = Explicit_Problem(pendulum, y0, t0, sw0=switches0) mod.state_events = state_events #Sets the state events to the problem mod.handle_event = handle_event #Sets the event handling to the problem mod.name = 'Bouncing Ball on Sonusoidal Platform' #Sets the name of the problem #Create an Assimulo solver (CVode) sim = CVode(mod) #sim = LSODAR(mod) sim.options['verbosity'] = 40 #Specifies options sim.discr = 'Adams' #Sets the discretization method sim.iter = 'FixedPoint' #Sets the iteration method sim.rtol = 1.e-8 #Sets the relative tolerance sim.atol = 1.e-6 #Sets the absolute tolerance return sim
def create_model(): def pendulum(t, X, sw): """ The ODE to be simulated. The parameter sw should be fixed during the simulation and only be changed during the event handling. """ X = X.copy() X[0] = X[1] X[1] = -1 + 0.04 * (X[1]**2) * np.sin(X[1]) X[2] = 1 return X def state_events(t, X, sw): """ This is our function that keep track of our events, when the sign of any of the events has changed, we have an event. """ return [X[0] - np.sin(X[2])] def handle_event(solver, event_info): """ Event handling. This functions is called when Assimulo finds an event as specified by the event functions. """ state_info = event_info[0] #We are only interested in state events info if state_info[0] != 0: #Check if the first event function have been triggered if solver.sw[0]: #If the switch is True the pendulum bounces X = solver.y if X[1] - np.cos(X[2]) < 0: X[1] = -0.9*X[1] + 1.9*np.cos(X[2]) #solver.sw[0] = not solver.sw[0] #Change event function #Initial values y0 = [0, 0, 0] #Initial states t0 = 0.0 #Initial time switches0 = [True] #Initial switches #Create an Assimulo Problem mod = Explicit_Problem(pendulum, y0, t0, sw0=switches0) mod.state_events = state_events #Sets the state events to the problem mod.handle_event = handle_event #Sets the event handling to the problem mod.name = 'Bouncing Ball on Sonusoidal Platform' #Sets the name of the problem #Create an Assimulo solver (CVode) sim = CVode(mod) #sim = LSODAR(mod) #sim.options['verbosity'] = 20 #LOUD sim.options['verbosity'] = 40 #WHISPER #sim.options['minh'] = 1e-4 #sim.options['rtol'] = 1e-3 #Specifies options sim.discr = 'Adams' #Sets the discretization method sim.iter = 'FixedPoint' #Sets the iteration method sim.rtol = 1.e-8 #Sets the relative tolerance sim.atol = 1.e-6 #Sets the absolute tolerance return sim
def create_model(): def pendulum(t, X, sw): """ The ODE to be simulated. The parameter sw should be fixed during the simulation and only be changed during the event handling. """ X = X.copy() X[0] = X[1] X[1] = -1 + 0.04 * (X[1]**2) * np.sin(X[1]) X[2] = 1 return X def state_events(t, X, sw): """ This is our function that keep track of our events, when the sign of any of the events has changed, we have an event. """ return [X[0] - np.sin(X[2])] def handle_event(solver, event_info): """ Event handling. This functions is called when Assimulo finds an event as specified by the event functions. """ state_info = event_info[ 0] #We are only interested in state events info if state_info[ 0] != 0: #Check if the first event function have been triggered if solver.sw[0]: #If the switch is True the pendulum bounces X = solver.y if X[1] - np.cos(X[2]) < 0: X[1] = -0.9 * X[1] + 1.9 * np.cos(X[2]) #solver.sw[0] = not solver.sw[0] #Change event function #Initial values y0 = [0, 0, 0] #Initial states t0 = 0.0 #Initial time switches0 = [True] #Initial switches #Create an Assimulo Problem mod = Explicit_Problem(pendulum, y0, t0, sw0=switches0) mod.state_events = state_events #Sets the state events to the problem mod.handle_event = handle_event #Sets the event handling to the problem mod.name = 'Bouncing Ball on Sonusoidal Platform' #Sets the name of the problem #Create an Assimulo solver (CVode) sim = CVode(mod) #sim = LSODAR(mod) #sim.options['verbosity'] = 20 #LOUD sim.options['verbosity'] = 40 #WHISPER #sim.options['minh'] = 1e-4 #sim.options['rtol'] = 1e-3 #Specifies options sim.discr = 'Adams' #Sets the discretization method sim.iter = 'FixedPoint' #Sets the iteration method sim.rtol = 1.e-8 #Sets the relative tolerance sim.atol = 1.e-6 #Sets the absolute tolerance return sim