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Re: [firedrake] imposing boundary conditions for Hermite element MixedFunctionSpace
by Matthew Knepley 17 Jul '25

17 Jul '25

On Thu, Jul 17, 2025 at 10:49 AM Smail Merabet <merabetsmail(a)gmail.com> wrote: > Dear Matthew, > thanks for reply, I tried this: > > psi = Constant(-0.03) > > # Create the full function in mixed space > > obs = Function(Vh, name="Obstacle") > > upp = Function(Vh, name="Upper") > > > obs_sub1 = obs.sub(1) > > upp_sub1 = upp.sub(1) > > # Interpolate into the subfunctions > > obs_sub1.interpolate(conditional(lt(psi, 0), 0, psi)) > I do not understand the Firedrake side, but did you plot your lower bound? I have no idea what conditional gives back. Thanks, Matt > upp_sub1.interpolate(Constant(1e10)) > > But the result doesn't satisfy the constraint $w \geq \psi$ > > Many Thanks > > On Thu, Jul 17, 2025 at 1:22 PM Matthew Knepley <knepley(a)gmail.com> wrote: > >> On Thu, Jul 17, 2025 at 7:52 AM Smail Merabet <merabetsmail(a)gmail.com> >> wrote: >> >>> Dear firedrake users, I try to solve a variational inequality using >>> snes-firedrake. >>> I have two unknown functions say (theta,w) >>> so the functionspace is Vh = MixedFunctionSpace([Th,Wh]) >>> where >>> Th = FunctionSpace(mesh, "Lagrange", 1) >>> Wh = FunctionSpace(mesh, "Lagrange", 2) >>> >>> >>> the inequality constraint concerns only $w$ >>> >>> I set : >>> obstacle = Function(Vh.sub(1)).interpolate((Constant(-0.03))) >>> upper = Function(Vh.sub(1)).interpolate(Constant(1e10)) >>> >> >> The SNES is operating on the full space, but you have interpolated >> constraints on the subspace. You have to inject those to full space vectors >> before setting the bounds. >> >> Thanks, >> >> Matt >> >> >>> *solver.solve(bounds=(obstacle, upper)) * >>> >>> but this line causes the following error: >>> >>> File "/Users/maths/Desktop/Firedrake/VI/Timoshenko-obs.py", line 64, in >>> <module> >>> solver.solve(bounds=(obstacle, upper)) >>> File "petsc4py/PETSc/Log.pyx", line 188, in >>> petsc4py.PETSc.Log.EventDecorator.decorator.wrapped_func >>> File "petsc4py/PETSc/Log.pyx", line 189, in >>> petsc4py.PETSc.Log.EventDecorator.decorator.wrapped_func >>> File >>> "/Users/maths/firedrake/src/firedrake/firedrake/adjoint_utils/variational_solver.py", >>> line 89, in wrapper >>> out = solve(self, **kwargs) >>> File >>> "/Users/maths/firedrake/src/firedrake/firedrake/variational_solver.py", >>> line 312, in solve >>> self.snes.setVariableBounds(lb, ub) >>> File "petsc4py/PETSc/SNES.pyx", line 1978, in >>> petsc4py.PETSc.SNES.setVariableBounds >>> petsc4py.PETSc.Error: error code 75 >>> [0] SNESVISetVariableBounds() at >>> /Users/maths/firedrake/src/petsc/src/snes/impls/vi/vi.c:424 >>> [0] SNESVISetVariableBounds_VI() at >>> /Users/maths/firedrake/src/petsc/src/snes/impls/vi/vi.c:443 >>> [0] Arguments are incompatible >>> [0] Incompatible vector lengths lower bound = 201 solution vector = 302 >>> >>> >>> Hope that one can help me ... >>> >>> Best regards. >>> Smail. >>> >>> On Fri, Apr 11, 2025 at 9:11 AM Smail Merabet <merabetsmail(a)gmail.com> >>> wrote: >>> >>>> Dear firedrake users, >>>> >>>> I try to solve a fourth-order 1d nonlinear problem using the Hermite >>>> element in firedrake. >>>> The functional space for the weak solution is: >>>> $$\mathcal{H}\times \mathcal{H}/times H^{2}_{0} $$ >>>> where, >>>> $$ >>>> \mathcal{H} = \left\lbrace f\in H^2([0,\ell]), \; f(0)=0, \; f'(0)=0 >>>> \right\rbrace. >>>> $$ >>>> I can't impose the boundary conditions correctly. When I compile the >>>> code, I get the following error: >>>> FiniteElement('Hermite', interval, 3), name=None, index=1, >>>> component=None), IndexedProxyFunctionSpace(<firedrake.mesh.MeshTopology >>>> object at 0x125a2ce80>, FiniteElement('Hermite', interval, 3), name=None, >>>> index=2, component=None), name='None_None_None'), >>>> Mesh(VectorElement(FiniteElement('Lagrange', interval, 1), dim=1), 0)), 9) >>>> defined on incompatible FunctionSpace! >>>> >>>> Note the same problem was implemented using FEniCS with C0-interior >>>> penalty method, in the reference (sec. 3 eq 3.12-3.13): >>>> >>>> Enhanced models for the nonlinear bending of planar rods: localization >>>> phenomena and multistability >>>> by: >>>> Matteo Brunetti , Antonino Favata and Stefano Vidoli. >>>> >>>> I attached the codes to this email. >>>> >>>> Thanks in advance >>>> Smail MERABET >>>> >>>> _______________________________________________ >>> firedrake mailing list >>> firedrake(a)imperial.ac.uk >>> https://mailman.ic.ac.uk/mailman/listinfo/firedrake >>> >> >> >> -- >> What most experimenters take for granted before they begin their >> experiments is infinitely more interesting than any results to which their >> experiments lead. >> -- Norbert Wiener >> >> https://www.cse.buffalo.edu/~knepley/ >> <http://www.cse.buffalo.edu/~knepley/> >> > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener https://www.cse.buffalo.edu/~knepley/ <http://www.cse.buffalo.edu/~knepley/>

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imposing boundary conditions for Hermite element MixedFunctionSpace
by Smail Merabet 17 Jul '25

17 Jul '25

Dear firedrake users, I try to solve a fourth-order 1d nonlinear problem using the Hermite element in firedrake. The functional space for the weak solution is: $$\mathcal{H}\times \mathcal{H}/times H^{2}_{0} $$ where, $$ \mathcal{H} = \left\lbrace f\in H^2([0,\ell]), \; f(0)=0, \; f'(0)=0 \right\rbrace. $$ I can't impose the boundary conditions correctly. When I compile the code, I get the following error: FiniteElement('Hermite', interval, 3), name=None, index=1, component=None), IndexedProxyFunctionSpace(<firedrake.mesh.MeshTopology object at 0x125a2ce80>, FiniteElement('Hermite', interval, 3), name=None, index=2, component=None), name='None_None_None'), Mesh(VectorElement(FiniteElement('Lagrange', interval, 1), dim=1), 0)), 9) defined on incompatible FunctionSpace! Note the same problem was implemented using FEniCS with C0-interior penalty method, in the reference (sec. 3 eq 3.12-3.13): Enhanced models for the nonlinear bending of planar rods: localization phenomena and multistability by: Matteo Brunetti , Antonino Favata and Stefano Vidoli. I attached the codes to this email. Thanks in advance Smail MERABET

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Solving Variational Inequality (vectorial case): pb self.snes.setVariableBounds(lb, ub)
by Smail Merabet 17 Jul '25

17 Jul '25

Dear firedrake users, I try to solve a variational inequality using snes-firedrake. I have two unknown functions say (theta,w) so the functionspace is Vh = MixedFunctionSpace([Th,Wh]) where Th = FunctionSpace(mesh, "Lagrange", 1) Wh = FunctionSpace(mesh, "Lagrange", 2) the inequality constraint concerns only $w$ I set : obstacle = Function(Vh.sub(1)).interpolate((Constant(-0.03))) upper = Function(Vh.sub(1)).interpolate(Constant(1e10)) *solver.solve(bounds=(obstacle, upper)) * but this line causes the following error: File "/Users/maths/Desktop/Firedrake/VI/Timoshenko-obs.py", line 64, in <module> solver.solve(bounds=(obstacle, upper)) File "petsc4py/PETSc/Log.pyx", line 188, in petsc4py.PETSc.Log.EventDecorator.decorator.wrapped_func File "petsc4py/PETSc/Log.pyx", line 189, in petsc4py.PETSc.Log.EventDecorator.decorator.wrapped_func File "/Users/maths/firedrake/src/firedrake/firedrake/adjoint_utils/variational_solver.py", line 89, in wrapper out = solve(self, **kwargs) File "/Users/maths/firedrake/src/firedrake/firedrake/variational_solver.py", line 312, in solve self.snes.setVariableBounds(lb, ub) File "petsc4py/PETSc/SNES.pyx", line 1978, in petsc4py.PETSc.SNES.setVariableBounds petsc4py.PETSc.Error: error code 75 [0] SNESVISetVariableBounds() at /Users/maths/firedrake/src/petsc/src/snes/impls/vi/vi.c:424 [0] SNESVISetVariableBounds_VI() at /Users/maths/firedrake/src/petsc/src/snes/impls/vi/vi.c:443 [0] Arguments are incompatible [0] Incompatible vector lengths lower bound = 201 solution vector = 302 Hope that one can help me ... Best regards. Smail.

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Help strengthen the security of your Google Account
by Google 04 Jun '25

04 Jun '25

[image: Google] Verify firedrake(a)imperial.ac.uk as your recovery email firedrake(a)imperial.ac.uk Verifying your recovery email will confirm that it’s an active email that belongs to you. Google can use your recovery email to contact you if you ever need help signing in or if we notice suspicious activity. Take action <https://accounts.google.com/AccountChooser?Email=firedrake@imperial.ac.uk&c…> You can also go directly to: https://myaccount.google.com/recovery/email You received this email to let you know about important changes to your Google Account and services. © 2025 Google LLC, 1600 Amphitheatre Parkway, Mountain View, CA 94043, USA

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1777275564
by slm4205b39b38＠outlook.com 29 Apr '25

29 Apr '25

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Firedrake 25 - save the date
by Cotter, Colin J 28 Apr '25

28 Apr '25

Dear Firedrakers, There will be a more formal announcement soon, but for now please save the dates: Monday 15 - Wednesday 17 September 2025 For Firedrake '25, which will take place in Leeds, hosted by Onno Bokhove and the Leeds Institute for Fluid Dynamics. All the best --cjc Professor Colin Cotter (he/him) Department of Mathematics 755, Huxley Building Imperial College London South Kensington Campus United Kingdom of Great Britain and Northern Ireland +44 2075943468

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firedrakeproject.org Needs to improve for better looks.
by Angelica Jerde 24 Mar '25

24 Mar '25

Dear Business owner of *firedrakeproject.org <http://firedrakeproject.org>*. Hope you are doing well! I have analysed your website.you seem to have a nice website. But the concern is, It needs to be an improved design for better looks and attractiveness with mobile responsiveness. So that visitors will see your services briefly as well as navigate one page to another page easily. While I was going through your website, I came across some factors which need to improve. Such as: · Your website needs to be mobile responsive. · At smaller screen, the texts are needed to be arranged in proper way · The design needs to improve for better looks and attractiveness. · Need to add well-organised Logo for your website · Need to add looking images to describe your business. · Images are too small to attract your visitors · Footer part also needs to improve your website. · Need to modify the favicon image according to your logo Colour combination always grabs visitor attention,that’s the reason it should be eye-catching.We can redesign your website responsively by writing the back end code with HTML5 and CSS3 technology with which your site will auto fit the device where it is being accessed. Let me know if I should share a customized plan as per your website requirement. Look forward to your kind response. *Best Regards,*Angelica Jerde *Marketing Consultant* -------------------------------------------------------------- *Note:* - Our next conversation will be on my corporate Email ID. Reply me with *"Quote",* if you are interested. Click *here* <https://aiwebproservice-dot-yamm-track.appspot.com/2OgL90O6vCzXWLayssSvqPRK…> to unsubscribe. [image: beacon]

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Firedrake use case hackathon 12th-14th Mat
by Shipton, Jemma 17 Mar '25

17 Mar '25

Hi All, We have exciting event coming up in May: use case hackathon at the beautiful Dartington Hall in Totnes. This is an opportunity to showcase what you do (or would like to do) with Firedrake, FEniCS or any of the packages that build on them. This is the first event in the newly funded Collaborative Computational Project spanning FEnICS and Firedrake. The CCP is subsidising this event heavily, so it’s an amazing value way to have some high productivity time with other users and developers, and to provide your input into how these packages develop into the future. Information and registration here: https://ccp-dcm.github.io/exeter_hackathon.html Please contact Jemma: j.shipton(a)exeter.ac.uk if you have any questions. All the best, Jemma

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Simulation quantum part. 1
by antony padilla 14 Mar '25

14 Mar '25

import numpy as np import scipy.linalg import matplotlib.pyplot as plt from mpl_toolkits.mplot3d import Axes3D ############################################################################## 1. Parámetros y configuración ############################################################################## hbar = 1.0 t_hop = 1.0 G = 1.0 M = 1.0 lambda_g = 0.2 dt = 0.02 steps = 50 factor para la evolución cuántica: exp(-iH dt / hbar) factor_evol = -1j * dt / hbar ############################################################################## 2. Definición del icosaedro base (sin deformación) ############################################################################## phi = (1 + np.sqrt(5)) / 2.0 base_vertices = np.array([ [-1, phi, 0], [ 1, phi, 0], [-1, -phi, 0], [ 1, -phi, 0], [ 0, -1, phi], [ 0, 1, phi], [ 0, -1, -phi], [ 0, 1, -phi], [ phi, 0, -1], [ phi, 0, 1], [-phi, 0, -1], [-phi, 0, 1] ], dtype=float) Normalizamos para que un vértice tenga radio 1 r0 = np.linalg.norm(base_vertices[0]) base_vertices /= r0 Lista de aristas del icosaedro (12 vértices, 30 aristas) edges = [ (0,1), (0,5), (0,7), (0,10), (0,11), (1,5), (1,7), (1,8), (1,9), (2,3), (2,6), (2,7), (2,9), (2,11), (3,6), (3,7), (3,8), (3,9), (4,5), (4,6), (4,9), (4,10), (4,11), (5,9), (5,10), (6,7), (6,9), (6,10), (7,8), (8,9), (8,10), (10,11) ] def build_adjacency_matrix(): """ Construye la matriz de adyacencia (12x12) con -t_hop en las posiciones correspondientes a las aristas. """ A = np.zeros((12, 12), dtype=complex) for (i, j) in edges: A[i, j] = -t_hop A[j, i] = -t_hop return A ############################################################################## 3. Potencial logarítmico estático (sin deformar vértices) ############################################################################## def build_potential_log(vertices): """ Calcula el potencial gravitatorio discreto V_G(i) = - sum(G*M / dist(i,j)) y luego aplica la corrección logarítmica V_log(i) = lambda_g * log(1 + V_G(i)). Como la geometría no cambia, este potencial es constante en el tiempo. """ N = len(vertices) V_G = np.zeros(N, dtype=float) for i in range(N): for j in range(N): if i != j: dist_ij = np.linalg.norm(vertices[i] - vertices[j]) V_G[i] += - (G * M / dist_ij) # Evitamos valores no válidos en la log min_val = np.min(V_G) shift = 0.0 if min_val <= -1.0: shift = -(min_val + 0.9999) V_log = lambda_g * np.log(1.0 + V_G + shift) return V_log ############################################################################## 4. Construcción del Hamiltoniano estático ############################################################################## adjacency = build_adjacency_matrix() El icosaedro permanece siempre igual (sin "update_vertices") Por tanto, calculamos el potencial logarítmico solo una vez: V_log_static = build_potential_log(base_vertices) Hamiltoniano total fijo: H = adjacency + diag(V_log_static) H_static = adjacency + np.diag(V_log_static) Operador de evolución para un paso de tiempo dt U_static = scipy.linalg.expm(factor_evol * H_static) ############################################################################## 5. Estado cuántico inicial y bucle de evolución ############################################################################## psi = np.zeros(12, dtype=complex) psi[0] = 1.0 # partícula localizada en el vértice 0 al inicio psi_t_history = [psi.copy()] for _ in range(steps): psi = U_static @ psi # Renormalizamos para evitar errores numéricos norm_psi = np.linalg.norm(psi) if norm_psi > 1e-12: psi /= norm_psi psi_t_history.append(psi.copy()) ############################################################################## 6. Visualización de resultados ############################################################################## prob_t = np.array([np.abs(state)**2 for state in psi_t_history]) Evolución de la probabilidad plt.figure(figsize=(10,6)) for i in range(12): plt.plot(prob_t[:, i], label=f'Vértice {i}') plt.xlabel('Paso de tiempo') plt.ylabel('Probabilidad') plt.title('Evolución de la probabilidad en un icosaedro estático (potencial fijo)') plt.legend(bbox_to_anchor=(1.05, 1.0), loc='upper left') plt.tight_layout() plt.show() Visualización 3D de la configuración final (los vértices no cambian) final_prob = prob_t[-1] fig = plt.figure(figsize=(7,7)) ax = fig.add_subplot(111, projection='3d') colors = plt.cm.viridis(final_prob / final_prob.max()) for i in range(12): x, y, z = base_vertices[i] ax.scatter(x, y, z, color=colors[i], s=50 + 400*final_prob[i]) ax.set_title('Configuración final en el icosaedro estático') plt.show() Antony Padilla Morales

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Re: [firedrake] Comprehensive Website Health Report
by Elliot 12 Mar '25

12 Mar '25

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