# Uncategorized **URL:** https://fenicsproject.discourse.group/c/uncategorized/1.md [Latest](https://fenicsproject.discourse.group/latest.md) · [Categories](https://fenicsproject.discourse.group/categories.md) · [Tags](https://fenicsproject.discourse.group/tags.md) --- ## [Parallelizing heat equation tutorial](https://fenicsproject.discourse.group/t/parallelizing-heat-equation-tutorial/11247)
**Author:** [@jeannafta](https://fenicsproject.discourse.group/u/jeannafta)\ **Replies:** 16\ **Last updated:** [September 11, 2025, 5:19pm UTC](https://fenicsproject.discourse.group/t/parallelizing-heat-equation-tutorial/11247 "2025-09-11T17:19:35Z")
Hello, Is there a simple way to parallelize the heat equation tutorial (Diffusion of a Gaussian function — FEniCSx tutorial) ? I am new to parallelization and I am wondering if the solver used in the tutorial is capabl… --- ## [A question regarding the complex support of FEniCSx](https://fenicsproject.discourse.group/t/a-question-regarding-the-complex-support-of-fenicsx/17595)
**Author:** [@LaserM](https://fenicsproject.discourse.group/u/LaserM)\ **Replies:** 1\ **Last updated:** [May 12, 2025, 12:10pm UTC](https://fenicsproject.discourse.group/t/a-question-regarding-the-complex-support-of-fenicsx/17595 "2025-05-12T12:10:19Z")
When I was studying the solution code for the Helmholtz equation, the tutorial mentioned, “This example is designed to be executed with complex-valued degrees of freedom. To be able to solve this problem, we use the comp… --- ## [Gather solutions in parallel in FEniCSX](https://fenicsproject.discourse.group/t/gather-solutions-in-parallel-in-fenicsx/5907)
**Author:** [@Yingqi\_Jia](https://fenicsproject.discourse.group/u/Yingqi_Jia)\ **Replies:** 9\ **Last updated:** [March 11, 2025, 8:01am UTC](https://fenicsproject.discourse.group/t/gather-solutions-in-parallel-in-fenicsx/5907 "2025-03-11T08:01:07Z")
Basically, I want to do the same thing mentioned in Gather solution in parallel - #2 by dajuno in FEniCSX. That is, I want to gather the results from every processor on processor 0. Specifically, I want to obtain the sam… --- ## [Thermo-Electromagnetic plasmonics coupling](https://fenicsproject.discourse.group/t/thermo-electromagnetic-plasmonics-coupling/17175)
**Author:** [@VladCucuiet](https://fenicsproject.discourse.group/u/VladCucuiet)\ **Replies:** 3\ **Last updated:** [March 10, 2025, 2:11pm UTC](https://fenicsproject.discourse.group/t/thermo-electromagnetic-plasmonics-coupling/17175 "2025-03-10T14:11:20Z")
Hello all, I would like to start research in thermo-electromagnetic simulations and I am wondering if it is possible with Fenics. Mainly, I will make first FDTD analysis of nanoparticles and then using the field as sou… --- ## [How to further speed up the calculation in doflinx?](https://fenicsproject.discourse.group/t/how-to-further-speed-up-the-calculation-in-doflinx/5465)
**Author:** [@Yingqi\_Jia](https://fenicsproject.discourse.group/u/Yingqi_Jia)\ **Replies:** 5\ **Last updated:** [February 26, 2025, 1:46pm UTC](https://fenicsproject.discourse.group/t/how-to-further-speed-up-the-calculation-in-doflinx/5465 "2025-02-26T13:46:55Z")
I am trying to run the default tutorial The equations of linear elasticity — FEniCS-X tutorial in the docker container, and want to test the computational time of the solver by using the time package. start\_time = time.… --- ## [MeshView submesh vertex map to parent mesh](https://fenicsproject.discourse.group/t/meshview-submesh-vertex-map-to-parent-mesh/2152)
**Author:** [@javijv4](https://fenicsproject.discourse.group/u/javijv4)\ **Replies:** 8\ **Last updated:** [December 18, 2024, 2:36am UTC](https://fenicsproject.discourse.group/t/meshview-submesh-vertex-map-to-parent-mesh/2152 "2024-12-18T02:36:41Z")
Hello, I am getting started in using the cecile/mixed-dimensional branch. I have a 3D cube geometry with a cylindric hole at the center. I have defined the inner surface of the cylinder as a 2D subdomain using \> class … --- ## [How to apply a load on a single point or a node](https://fenicsproject.discourse.group/t/how-to-apply-a-load-on-a-single-point-or-a-node/4799)
**Author:** [@Owodou](https://fenicsproject.discourse.group/u/Owodou)\ **Replies:** 46\ **Last updated:** [December 12, 2024, 9:25am UTC](https://fenicsproject.discourse.group/t/how-to-apply-a-load-on-a-single-point-or-a-node/4799 "2024-12-12T09:25:19Z")
I am using FEniCs to apply a load on particular point of a square mesh. When checking people has proposed to use Pointwise but it seems to be a method to fix a displacement, others has proposed to use PointSource but thi… --- ## [How to define a Function in a submesh based on function values present in an adjoining submesh?](https://fenicsproject.discourse.group/t/how-to-define-a-function-in-a-submesh-based-on-function-values-present-in-an-adjoining-submesh/4047)
**Author:** [@Sabarish\_Gopi](https://fenicsproject.discourse.group/u/Sabarish_Gopi)\ **Replies:** 14\ **Last updated:** [December 10, 2024, 2:25pm UTC](https://fenicsproject.discourse.group/t/how-to-define-a-function-in-a-submesh-based-on-function-values-present-in-an-adjoining-submesh/4047 "2024-12-10T14:25:16Z")
Hello, I have two submeshes - 1 and 2 as shown below. They share a common boundary between them. I have a function u defined on the function space, Vusb1 in the top submesh. I have obtained this function by solving a… --- ## [Superlu\_dist solver](https://fenicsproject.discourse.group/t/superlu-dist-solver/6475)
**Author:** [@Ovais](https://fenicsproject.discourse.group/u/Ovais)\ **Replies:** 16\ **Last updated:** [December 10, 2024, 12:46pm UTC](https://fenicsproject.discourse.group/t/superlu-dist-solver/6475 "2024-12-10T12:46:20Z")
Hi there, I am trying to figure out which fenics version or installation type comes with pre installed superlu\_dist solver. I have tried installing the latest version but once i print list of solvers using “list\_linear\_… --- ## [Real Element Type in DolfinX](https://fenicsproject.discourse.group/t/real-element-type-in-dolfinx/8956)
**Author:** [@Gunasheela](https://fenicsproject.discourse.group/u/Gunasheela)\ **Replies:** 12\ **Last updated:** [November 27, 2024, 12:57pm UTC](https://fenicsproject.discourse.group/t/real-element-type-in-dolfinx/8956 "2024-11-27T12:57:16Z")
Hi, I need to use “Real type element” within the mixed function space in dolfinx, as shown below, but I run into the error as attached below, Is there a way I can fix this? or what is the replacement for real type eleme… --- ## [Does Fenicsx support spectral element methods?](https://fenicsproject.discourse.group/t/does-fenicsx-support-spectral-element-methods/9354)
**Author:** [@00krishna](https://fenicsproject.discourse.group/u/00krishna)\ **Replies:** 2\ **Last updated:** [November 8, 2024, 9:35am UTC](https://fenicsproject.discourse.group/t/does-fenicsx-support-spectral-element-methods/9354 "2024-11-08T09:35:33Z")
Hello all. I am totally new to Fenicsx though I have been going through some of the tutorials. I was wondering whether Fenicsx support spectral element methods. I have been searching for “spectral elements” in the pytho… --- ## [Conda install dolfinx for complex-valued problem](https://fenicsproject.discourse.group/t/conda-install-dolfinx-for-complex-valued-problem/8892)
**Author:** [@ricardo8r](https://fenicsproject.discourse.group/u/ricardo8r)\ **Replies:** 11\ **Last updated:** [October 29, 2024, 5:25pm UTC](https://fenicsproject.discourse.group/t/conda-install-dolfinx-for-complex-valued-problem/8892 "2024-10-29T17:25:11Z")
Hello all, Any way I can install or switch the conda installation to complex-valued dolfinx? Thanks for the help, Ricardo --- ## [Hermite functionspace with unitinterval mesh](https://fenicsproject.discourse.group/t/hermite-functionspace-with-unitinterval-mesh/10300)
**Author:** [@Younghwa\_Park](https://fenicsproject.discourse.group/u/Younghwa_Park)\ **Replies:** 17\ **Last updated:** [October 24, 2024, 8:09pm UTC](https://fenicsproject.discourse.group/t/hermite-functionspace-with-unitinterval-mesh/10300 "2024-10-24T20:09:32Z")
Hi, What I code up is Euler bernoulli beam. So, it is necessary to consider function in Hermite. The error shows is ValueError: Unknown element family: Hermite with cell type interval. To do that, what kind of mesh u… --- ## [Polygonial domain for optimization problem](https://fenicsproject.discourse.group/t/polygonial-domain-for-optimization-problem/7729)
**Author:** [@FlorianWill](https://fenicsproject.discourse.group/u/FlorianWill)\ **Replies:** 2\ **Last updated:** [October 3, 2024, 3:09pm UTC](https://fenicsproject.discourse.group/t/polygonial-domain-for-optimization-problem/7729 "2024-10-03T15:09:44Z")
Hello everybody, for computing hyperelastic buckling problems I have set up the following code: from \_\_future\_\_ import print\_function from mshr import \* import numpy as np from mpl\_toolkits.mplot3d import Axes3D from d… --- ## [Solving Hyperbolic problem](https://fenicsproject.discourse.group/t/solving-hyperbolic-problem/6262)
**Author:** [@RAVINA](https://fenicsproject.discourse.group/u/RAVINA)\ **Replies:** 6\ **Last updated:** [October 3, 2024, 2:38am UTC](https://fenicsproject.discourse.group/t/solving-hyperbolic-problem/6262 "2024-10-03T02:38:45Z")
Hello everyone, I want to solve a hyperbolic pde . Can we solve it in fenics? If yes then kindly suggest me some example. Thank you. --- ## [Internal vector arrangement and numpy automatic broadcasting](https://fenicsproject.discourse.group/t/internal-vector-arrangement-and-numpy-automatic-broadcasting/15861)
**Author:** [@MPenaR](https://fenicsproject.discourse.group/u/MPenaR)\ **Replies:** 3\ **Last updated:** [September 23, 2024, 8:32am UTC](https://fenicsproject.discourse.group/t/internal-vector-arrangement-and-numpy-automatic-broadcasting/15861 "2024-09-23T08:32:38Z")
I wanted to interpolate an expression of the form: f\\left(\\mathbf{x}\\right) = \\left\\Vert \\mathbf{x} - \\mathbf{a} \\right\\Vert which meant evaluating \\left\\Vert\\mathbf{x}\_i-\\mathbf{a}\\right\\Vert,\\quad i=1,2,\\dots,N\_\\m… --- ## [Problem with GMSH boundary markers](https://fenicsproject.discourse.group/t/problem-with-gmsh-boundary-markers/9200)
**Author:** [@nami](https://fenicsproject.discourse.group/u/nami)\ **Replies:** 1\ **Last updated:** [September 4, 2022, 9:55pm UTC](https://fenicsproject.discourse.group/t/problem-with-gmsh-boundary-markers/9200 "2022-09-04T21:55:57Z")
Hi, I have noticed something strange with GMSH boundary markers. They work with Dirichlet BCs but not with ds. I have the following GMSH file made by GMSH 3.0.4: // Gmsh project created on Sat Aug 20 11:37:10 2022 Poin… --- ## [Apply Multipoint constraint in Mixedelement Functionspace](https://fenicsproject.discourse.group/t/apply-multipoint-constraint-in-mixedelement-functionspace/7768)
**Author:** [@Gunasheela](https://fenicsproject.discourse.group/u/Gunasheela)\ **Replies:** 8\ **Last updated:** [August 25, 2024, 5:28pm UTC](https://fenicsproject.discourse.group/t/apply-multipoint-constraint-in-mixedelement-functionspace/7768 "2024-08-25T17:28:56Z")
Hi, I am performing frequency domain analysis of a piezoelectric cube model. The boundary conditions for the mechanical part: prescribed displacement at the left face, electrical part: grounded or zero voltage at the b… --- ## [How to set confining pressure with 3D cylinder in FEniCS?](https://fenicsproject.discourse.group/t/how-to-set-confining-pressure-with-3d-cylinder-in-fenics/5997)
**Author:** [@zhang](https://fenicsproject.discourse.group/u/zhang)\ **Replies:** 4\ **Last updated:** [August 23, 2024, 2:39am UTC](https://fenicsproject.discourse.group/t/how-to-set-confining-pressure-with-3d-cylinder-in-fenics/5997 "2024-08-23T02:39:35Z")
Hi, I am now performing deformation analysis on a three-dimensional cylindrical specimen. When performing a triaxial compression test, it is necessary to set a confining pressure on the surface of the cylinder, and the … --- ## [RuntimeWarning: mpi4py.MPI.File size changed, may indicate binary incompatibility. Expected 32 from C header, got 40 from PyObject def compile\_class(cpp\_data, mpi\_comm=MPI.comm\_world):](https://fenicsproject.discourse.group/t/runtimewarning-mpi4py-mpi-file-size-changed-may-indicate-binary-incompatibility-expected-32-from-c-header-got-40-from-pyobject-def-compile-class-cpp-data-mpi-comm-mpi-comm-world/6496)
**Author:** [@Jaouane\_Mohammed](https://fenicsproject.discourse.group/u/Jaouane_Mohammed)\ **Replies:** 6\ **Last updated:** [August 18, 2024, 1:07pm UTC](https://fenicsproject.discourse.group/t/runtimewarning-mpi4py-mpi-file-size-changed-may-indicate-binary-incompatibility-expected-32-from-c-header-got-40-from-pyobject-def-compile-class-cpp-data-mpi-comm-mpi-comm-world/6496 "2024-08-18T13:07:27Z")
Hello everyone, I hope everyone is OK. can you anyone help me to fix a problem. I am using the Fenics project on ubuntu. I try to run " import fenics " I got the following error : RuntimeWarning: mpi4py.MPI.File siz… --- ## [How to make parameters\['ghost mode'\]='shared\_facet' work in parallel with periodic boundary conditions?](https://fenicsproject.discourse.group/t/how-to-make-parameters-ghost-mode-shared-facet-work-in-parallel-with-periodic-boundary-conditions/4218)
**Author:** [@Rochishnu\_Chowdhury](https://fenicsproject.discourse.group/u/Rochishnu_Chowdhury)\ **Replies:** 5\ **Last updated:** [August 12, 2024, 12:51pm UTC](https://fenicsproject.discourse.group/t/how-to-make-parameters-ghost-mode-shared-facet-work-in-parallel-with-periodic-boundary-conditions/4218 "2024-08-12T12:51:04Z")
sample code parameters\[‘ghost\_mode’\] = ‘shared\_facet’ class PeriodicBoundary(SubDomain): def inside(self, x, on\_boundary): dir\_x = bool(x\[0\] \< DOLFIN\_EPS and x\[0\] \> -DOLFIN\_EPS and on\_boundary) dir\_y = bool(x\[1\] \< D… --- ## [Plasticity in fenics](https://fenicsproject.discourse.group/t/plasticity-in-fenics/818)
**Author:** [@Peter\_James](https://fenicsproject.discourse.group/u/Peter_James)\ **Replies:** 42\ **Last updated:** [July 23, 2024, 4:23pm UTC](https://fenicsproject.discourse.group/t/plasticity-in-fenics/818 "2024-07-23T16:23:01Z")
Dear all, I am trying to implement plasticity in FEniCS. I find an extremely valuable tutorial here (Courtesy @bleyerj ). Thanks a ton @bleyerj . I tried to match the result of the FEniCS code with the Abaqus so that I … --- ## [Picard Iteration Not Updating Properly](https://fenicsproject.discourse.group/t/picard-iteration-not-updating-properly/562)
**Author:** [@ZOlsen](https://fenicsproject.discourse.group/u/ZOlsen)\ **Replies:** 2\ **Last updated:** [April 12, 2019, 3:35am UTC](https://fenicsproject.discourse.group/t/picard-iteration-not-updating-properly/562 "2019-04-12T03:35:20Z")
Hey everyone, I’m new here. I’m having an issue trying to solve the steady NS equation with a Picard Iteration. I’m trying to just solve the pressure driven flow through a channel with an incline. After one iteration, th… --- ## [RuntimeError: Could not find DOLFIN pkg-config file. Please make sure appropriate paths are set](https://fenicsproject.discourse.group/t/runtimeerror-could-not-find-dolfin-pkg-config-file-please-make-sure-appropriate-paths-are-set/8180)
**Author:** [@Ryan\_Vogt1](https://fenicsproject.discourse.group/u/Ryan_Vogt1)\ **Replies:** 2\ **Last updated:** [June 28, 2024, 5:30pm UTC](https://fenicsproject.discourse.group/t/runtimeerror-could-not-find-dolfin-pkg-config-file-please-make-sure-appropriate-paths-are-set/8180 "2024-06-28T17:30:19Z")
Howdy, I merely ran conda create -n fenicsproject -c conda-forge python=3.7 fenics mshr ipython or also tried conda create -n fenicsproject -c conda-forge python=3.7 fenics-dolfin mshr ipython and then try to just imp… --- ## [Problem with Fenics and MacOS Catalina](https://fenicsproject.discourse.group/t/problem-with-fenics-and-macos-catalina/2106)
**Author:** [@gasberry](https://fenicsproject.discourse.group/u/gasberry)\ **Replies:** 1\ **Last updated:** [June 28, 2024, 4:31pm UTC](https://fenicsproject.discourse.group/t/problem-with-fenics-and-macos-catalina/2106 "2024-06-28T16:31:26Z")
I was just trying to import fenics module but I encountered the following issue. import fenics Traceback (most recent call last): File “”, line 1, in File “/Users/giulio/anaconda3/envs/fenicsproject/lib/python3.7… --- ## [Multipy mesh with coefficient](https://fenicsproject.discourse.group/t/multipy-mesh-with-coefficient/7065)
**Author:** [@giannoko](https://fenicsproject.discourse.group/u/giannoko)\ **Replies:** 5\ **Last updated:** [June 25, 2024, 3:47pm UTC](https://fenicsproject.discourse.group/t/multipy-mesh-with-coefficient/7065 "2024-06-25T15:47:50Z")
Hello, I have an 1D mesh ranging from 0 to 1. How can I multiply all the nodes with a constant coefficient to get a new mesh? --- ## [How to extract the force on a hole boundary?](https://fenicsproject.discourse.group/t/how-to-extract-the-force-on-a-hole-boundary/3465)
**Author:** [@Daniel](https://fenicsproject.discourse.group/u/Daniel)\ **Replies:** 5\ **Last updated:** [June 10, 2024, 4:06pm UTC](https://fenicsproject.discourse.group/t/how-to-extract-the-force-on-a-hole-boundary/3465 "2024-06-10T16:06:22Z")
hi everyone, this is a displacement controlled problem. right hole if fixed and left hole is applied a delta-u step by step. I want to calculate the traction on the left hole. thanks in advance --- ## [Problem with creating vector with scalar function components](https://fenicsproject.discourse.group/t/problem-with-creating-vector-with-scalar-function-components/5383)
**Author:** [@avishmj](https://fenicsproject.discourse.group/u/avishmj)\ **Replies:** 45\ **Last updated:** [June 10, 2024, 1:15pm UTC](https://fenicsproject.discourse.group/t/problem-with-creating-vector-with-scalar-function-components/5383 "2024-06-10T13:15:31Z")
Hello! In my problem I solved the Poisson equation for a unidirectional flow V=(0, 0, u (x, y)). I solved for u = u(x, y) successfully and implemented the following code to form the vector V and the stress tensor S in f… --- ## [Import Error when running fenicsx on colab](https://fenicsproject.discourse.group/t/import-error-when-running-fenicsx-on-colab/11586)
**Author:** [@Magnus\_Gohm](https://fenicsproject.discourse.group/u/Magnus_Gohm)\ **Replies:** 3\ **Last updated:** [June 6, 2024, 2:36pm UTC](https://fenicsproject.discourse.group/t/import-error-when-running-fenicsx-on-colab/11586 "2024-06-06T14:36:21Z")
Hello, I installed fenicsx on google colab using try: import dolfinx except ImportError: !wget "https://fem-on-colab.github.io/releases/fenicsx-install-real.sh" -O "/tmp/fenicsx-install.sh" && bash "/tmp/fenics… --- ## [Contact Mechanics - Displacement Field Overlapping](https://fenicsproject.discourse.group/t/contact-mechanics-displacement-field-overlapping/8322)
**Author:** [@Ekrem\_Ekici](https://fenicsproject.discourse.group/u/Ekrem_Ekici)\ **Replies:** 2\ **Last updated:** [June 4, 2024, 6:59pm UTC](https://fenicsproject.discourse.group/t/contact-mechanics-displacement-field-overlapping/8322 "2024-06-04T18:59:32Z")
Hi there, I am doing simply linear elasticity simulation for very complex geometry. You can see the geometry and boundary conditions below; I adopted the linear\_elacticity demo (I cannot share the geometry file-sinc… [Next page](https://fenicsproject.discourse.group/c/uncategorized/1.md?page=1)