# Bempp

**URL:** https://bempp.discourse.group/c/bempp/7.md

[Latest](https://bempp.discourse.group/latest.md) · [Categories](https://bempp.discourse.group/categories.md)

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## [About the Bempp category](https://bempp.discourse.group/t/about-the-bempp-category/22)

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**Author:** [@mscroggs](https://bempp.discourse.group/u/mscroggs)\
**Replies:** 0

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Posts in this category are about the development of Bempp, including discussion of new functionality.

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## [OPENCL with AMD EPYC CPU](https://bempp.discourse.group/t/opencl-with-amd-epyc-cpu/358)

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**Author:** [@Bastos](https://bempp.discourse.group/u/Bastos)\
**Replies:** 0\
**Last updated:** [11 June 2026 09:27 UTC](https://bempp.discourse.group/t/opencl-with-amd-epyc-cpu/358 "2026-06-11T09:27:46Z")

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Hello everyone, I am currently trying to calculate some magnetic flux with a refined mesh. Therefore, I am using opencl. The thing is that I am now using an AMD CPU (EPYC 96 core). As I am not really used to AMD stuff, …

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## [How to import grid with results](https://bempp.discourse.group/t/how-to-import-grid-with-results/347)

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**Author:** [@S.L](https://bempp.discourse.group/u/S.L)\
**Replies:** 1\
**Last updated:** [6 March 2026 12:41 UTC](https://bempp.discourse.group/t/how-to-import-grid-with-results/347 "2026-03-06T12:41:12Z")

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Thank you for the Bempp discussion platform! I have encountered the following issues and would like to discuss them with everyone. My question is Can Bempp import grids with result data? I would like to skip the proces…

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## [Dolfinx + BEMpp in parallel](https://bempp.discourse.group/t/dolfinx-bempp-in-parallel/349)

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**Author:** [@a-lyrae](https://bempp.discourse.group/u/a-lyrae)\
**Replies:** 0\
**Last updated:** [21 November 2025 14:33 UTC](https://bempp.discourse.group/t/dolfinx-bempp-in-parallel/349 "2025-11-21T14:33:11Z")

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Hi all, I would like to use dolfinx+bempp to solve a magnetostatic problem, which has a boundary condition: phi1\_boundary=BEM\*phi0\_boundary. I create a distributed mesh with dolfinx and would like to use bempp to handle…

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## [Error in example scripts](https://bempp.discourse.group/t/error-in-example-scripts/341)

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**Author:** [@alanlindsay](https://bempp.discourse.group/u/alanlindsay)\
**Replies:** 2\
**Last updated:** [15 September 2025 11:56 UTC](https://bempp.discourse.group/t/error-in-example-scripts/341 "2025-09-15T11:56:15Z")

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Hi there, I’m trying to familiarize myself with bempp by running the example scripts. I’m getting the following error related to the gmres solver: For example, when executing line 72 of the reentrant cube capacitance e…

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## [Installing bempp on Apple M1 silicon](https://bempp.discourse.group/t/installing-bempp-on-apple-m1-silicon/333)

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**Author:** [@bmitra](https://bempp.discourse.group/u/bmitra)\
**Replies:** 2\
**Last updated:** [30 May 2025 14:04 UTC](https://bempp.discourse.group/t/installing-bempp-on-apple-m1-silicon/333 "2025-05-30T14:04:06Z")

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I am unable to install via anaconda: This is the error that I get. On conda-forge they only have osx-64 channel. No osx-arm64 channel. Has anyone installed bempp on apple silicon ? “”" Platform: osx-arm64 Collecting p…

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## [How to calculate the RCS of 2D target?](https://bempp.discourse.group/t/how-to-calculate-the-rcs-of-2d-target/325)

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**Author:** [@MushishiYako](https://bempp.discourse.group/u/MushishiYako)\
**Replies:** 2\
**Last updated:** [30 April 2025 09:22 UTC](https://bempp.discourse.group/t/how-to-calculate-the-rcs-of-2d-target/325 "2025-04-30T09:22:10Z")

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Hello there! My problem discribed with the help of deepseek is as follow: To compare the differences in the radar cross section (RCS) of 2D targets calculated using the Finite Element Method (FEM) and the Method of Mom…

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## [Normals not oriented in Fem-Bem coupling tutorial](https://bempp.discourse.group/t/normals-not-oriented-in-fem-bem-coupling-tutorial/300)

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**Author:** [@mknoeller](https://bempp.discourse.group/u/mknoeller)\
**Replies:** 5\
**Last updated:** [20 March 2025 16:11 UTC](https://bempp.discourse.group/t/normals-not-oriented-in-fem-bem-coupling-tutorial/300 "2025-03-20T16:11:51Z")

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Dear Bempp team and community, (accidentally I deleted my last post when I wanted to add something) when running the tutorial for the Fem-Bem coupling “Simple FEM-BEM coupling for the Helmholtz equation with FEniCSx” I…

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## [\[announcement\] import bempp\_cl.api](https://bempp.discourse.group/t/announcement-import-bempp-cl-api/317)

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**Author:** [@mscroggs](https://bempp.discourse.group/u/mscroggs)\
**Replies:** 0\
**Last updated:** [20 March 2025 16:09 UTC](https://bempp.discourse.group/t/announcement-import-bempp-cl-api/317 "2025-03-20T16:09:26Z")

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Hello everyone, I’ve just merged a PR that renames the Python module in bempp-cl from bempp to bempp\_cl. The reason for this is so that bempp-cl can be more easily used alongside (the still very experimental) bempp-rs. …

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## [Bempp for electromagnetic wave transportation question](https://bempp.discourse.group/t/bempp-for-electromagnetic-wave-transportation-question/304)

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**Author:** [@Liang](https://bempp.discourse.group/u/Liang)\
**Replies:** 0\
**Last updated:** [20 January 2025 14:25 UTC](https://bempp.discourse.group/t/bempp-for-electromagnetic-wave-transportation-question/304 "2025-01-20T14:25:13Z")

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Hello. I saw many examples of using Bempp to calculate the EM scattering problems. I wonder if Bempp can also be used to calculate the EM wave propagating in a waveguide structure. In this case, how I can excite a proper…

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## [Dof transformations not supported by bempp-cl](https://bempp.discourse.group/t/dof-transformations-not-supported-by-bempp-cl/250)

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**Author:** [@Gabriel](https://bempp.discourse.group/u/Gabriel)\
**Replies:** 1\
**Last updated:** [29 October 2024 14:22 UTC](https://bempp.discourse.group/t/dof-transformations-not-supported-by-bempp-cl/250 "2024-10-29T14:22:56Z")

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Hello, I am concerned with Maxwell problems and was very impressed by BEMpp capabilities described in the Scroggs & al. 2017 paper (Redirecting). The tutorials maxwell\_dielectric and maxwell\_screen in Jupyter notebooks …

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## [Problems in space creation from imported grid](https://bempp.discourse.group/t/problems-in-space-creation-from-imported-grid/292)

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**Author:** [@diego](https://bempp.discourse.group/u/diego)\
**Replies:** 1\
**Last updated:** [11 October 2024 19:31 UTC](https://bempp.discourse.group/t/problems-in-space-creation-from-imported-grid/292 "2024-10-11T19:31:21Z")

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Hello, I am new to bempp. I created a grid (using a convex hull algorthm) outside bempp environment and imported it. grid.plot() looks fine. However, when running A0\_int = multitrace\_operator(grid, k\_int, epsilon\_r=epsi…

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## [OpenCl in Windows 10](https://bempp.discourse.group/t/opencl-in-windows-10/165)

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**Author:** [@marc.jofre](https://bempp.discourse.group/u/marc.jofre)\
**Replies:** 1\
**Last updated:** [30 September 2024 09:39 UTC](https://bempp.discourse.group/t/opencl-in-windows-10/165 "2024-09-30T09:39:27Z")

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Hi, I have managed to install OpenCL in Windows 10 and Bempp detecting it on Jupyter Python. I installed the following drivers: Intel® CPU Runtime for OpenCL™ Applications 18.1 for Windows\* OS (64bit or 32bit) From: O…

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## [Bempp+plotly+dash compiled with pyinstaller does not launch due to gmsh dependencye](https://bempp.discourse.group/t/bempp-plotly-dash-compiled-with-pyinstaller-does-not-launch-due-to-gmsh-dependencye/269)

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**Author:** [@FrOl](https://bempp.discourse.group/u/FrOl)\
**Replies:** 0\
**Last updated:** [5 June 2024 07:25 UTC](https://bempp.discourse.group/t/bempp-plotly-dash-compiled-with-pyinstaller-does-not-launch-due-to-gmsh-dependencye/269 "2024-06-05T07:25:18Z")

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Hi I want to make an exe file using pyinstaller from a Dash app using bempp and plotly. Due to gmsh dependency the app does not launch. Is there a proper way to proceed with pyinstaller or bempp to fix this?

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## [Delta gap in dipole antenna](https://bempp.discourse.group/t/delta-gap-in-dipole-antenna/256)

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**Author:** [@AnthonyTSV](https://bempp.discourse.group/u/AnthonyTSV)\
**Replies:** 1\
**Last updated:** [26 April 2024 13:36 UTC](https://bempp.discourse.group/t/delta-gap-in-dipole-antenna/256 "2024-04-26T13:36:28Z")

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Hello there! How would one simulate a dipole antenna with a delta gap, i.e. a gap between two cylinders connected with an edge, that is being excited? I created two cylinders with a gap connected with a line in gmsh. B…

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## [How to export potential operator as matrix](https://bempp.discourse.group/t/how-to-export-potential-operator-as-matrix/202)

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**Author:** [@Marco](https://bempp.discourse.group/u/Marco)\
**Replies:** 2\
**Last updated:** [26 April 2024 13:28 UTC](https://bempp.discourse.group/t/how-to-export-potential-operator-as-matrix/202 "2024-04-26T13:28:04Z")

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Hi, I want to construct an “acoustic transfer matrix”, which maps source pressure on the boundary to the field points. Construction of the transfer matrix requires operator inverse on the boundary operator. Yes, I can c…

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## [TypeError: 'SumBlockedOperator' object is not subscriptable](https://bempp.discourse.group/t/typeerror-sumblockedoperator-object-is-not-subscriptable/237)

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**Author:** [@gerard](https://bempp.discourse.group/u/gerard)\
**Replies:** 0\
**Last updated:** [27 February 2024 16:11 UTC](https://bempp.discourse.group/t/typeerror-sumblockedoperator-object-is-not-subscriptable/237 "2024-02-27T16:11:03Z")

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Hello all, with BEMpp 0.3.1, when trying the snippets of figures 9 (preconditioned EFIE) and 13 (MFIE) extract from the 2017 amazing paper Redirecting. import numpy as np import bempp.api from bempp.api.operators.bound…

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## [Error in barycentric refinement of order 1 P space](https://bempp.discourse.group/t/error-in-barycentric-refinement-of-order-1-p-space/227)

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**Author:** [@Raphael](https://bempp.discourse.group/u/Raphael)\
**Replies:** 2\
**Last updated:** [22 January 2024 10:51 UTC](https://bempp.discourse.group/t/error-in-barycentric-refinement-of-order-1-p-space/227 "2024-01-22T10:51:05Z")

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Dear Bempp team, I think there is an implementation error in the barycentric refinement of the order 1 P space in Bempp-cl 0.3.1. Calling bempp.api.space.scalar\_spaces.p1\_barycentric\_continuous\_function\_space(coarse\_spa…

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## [Error in surface curl function](https://bempp.discourse.group/t/error-in-surface-curl-function/231)

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**Author:** [@Raphael](https://bempp.discourse.group/u/Raphael)\
**Replies:** 0\
**Last updated:** [16 January 2024 08:22 UTC](https://bempp.discourse.group/t/error-in-surface-curl-function/231 "2024-01-16T08:22:49Z")

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Dear Bempp team, I think there is an implementation error in the surface\_curl function of the bempp.api.space.FunctionSpace class in Bempp-cl 0.3.1. There are two input arguments missing in the returned numba\_surface\_cu…

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## [The fem-bem couple code error using dolfinx](https://bempp.discourse.group/t/the-fem-bem-couple-code-error-using-dolfinx/230)

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**Author:** [@jia](https://bempp.discourse.group/u/jia)\
**Replies:** 0\
**Last updated:** [16 January 2024 06:47 UTC](https://bempp.discourse.group/t/the-fem-bem-couple-code-error-using-dolfinx/230 "2024-01-16T06:47:39Z")

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Hello everyone, I am following the tutorial for the latest fem-bem couple solver. When I was running such code, I got such error below, which is seems like the memory leak. I has used the valgrind and the result shows t…

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## [How can I define a MtE operator on a bounded plane?](https://bempp.discourse.group/t/how-can-i-define-a-mte-operator-on-a-bounded-plane/221)

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**Author:** [@Yonglin](https://bempp.discourse.group/u/Yonglin)\
**Replies:** 1\
**Last updated:** [12 January 2024 14:53 UTC](https://bempp.discourse.group/t/how-can-i-define-a-mte-operator-on-a-bounded-plane/221 "2024-01-12T14:53:46Z")

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I want to define a MtE operator T such that T(n × E) = n × H on Γ where Γ = { (x,y,0) | 0 \< x \< 1, 0 \< y \< 1}. (E, H) satisfies the homogeneous Maxwell equations in the upper space { z \> 0 }. How can I do this?

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## [Error in calculating grid function in a particular grid](https://bempp.discourse.group/t/error-in-calculating-grid-function-in-a-particular-grid/207)

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**Author:** [@AsaWoojunLee](https://bempp.discourse.group/u/AsaWoojunLee)\
**Replies:** 1\
**Last updated:** [26 September 2023 00:06 UTC](https://bempp.discourse.group/t/error-in-calculating-grid-function-in-a-particular-grid/207 "2023-09-26T00:06:04Z")

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Hello, I am Woojun Lee and a PhD student at ECE department of Virginia tech. I am just trying to use Bempp to calculate impedance on a two-ported microstrip structure. For that, I meshed a cuboid structure with some h…

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## [Simulation crashed on an Electromagnetic scatteirng problem](https://bempp.discourse.group/t/simulation-crashed-on-an-electromagnetic-scatteirng-problem/182)

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**Author:** [@mandyxmq](https://bempp.discourse.group/u/mandyxmq)\
**Replies:** 2\
**Last updated:** [15 July 2023 16:05 UTC](https://bempp.discourse.group/t/simulation-crashed-on-an-electromagnetic-scatteirng-problem/182 "2023-07-15T16:05:31Z")

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I copied my github issue report here in case people in the forum have encountered this before. Hi, I tried Bempp on electromagnetic scattering problems and the jupyter kernel crashed. The simulation was running for seve…

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## [Running minial example: gmsh returned non-zero exit status 1](https://bempp.discourse.group/t/running-minial-example-gmsh-returned-non-zero-exit-status-1/199)

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**Author:** [@electroflow](https://bempp.discourse.group/u/electroflow)\
**Replies:** 2\
**Last updated:** [17 June 2023 04:47 UTC](https://bempp.discourse.group/t/running-minial-example-gmsh-returned-non-zero-exit-status-1/199 "2023-06-17T04:47:59Z")

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Hi all, I am running Windows 10 with Python 3.11. I have installed bmepp and gmsh using pip. When running import bempp.api import numpy as np grid = bempp.api.shapes.sphere(h=0.1) I get the Error Command ‘C:\\progra…

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## [PlotGrids and GridFunctions in Google Colab](https://bempp.discourse.group/t/plotgrids-and-gridfunctions-in-google-colab/167)

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**Author:** [@marc.jofre](https://bempp.discourse.group/u/marc.jofre)\
**Replies:** 1\
**Last updated:** [24 January 2023 18:22 UTC](https://bempp.discourse.group/t/plotgrids-and-gridfunctions-in-google-colab/167 "2023-01-24T18:22:36Z")

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Hi, I could not plot grids in Google Colab. I amanaged to show them with the below code: def Bempp\_configure\_plotly\_browser\_state(): import IPython display(IPython.core.display.HTML(''' \<script src="/…

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## [Identify point to a DOF - Source drive](https://bempp.discourse.group/t/identify-point-to-a-dof-source-drive/161)

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**Author:** [@marc.jofre](https://bempp.discourse.group/u/marc.jofre)\
**Replies:** 2\
**Last updated:** [28 December 2022 20:38 UTC](https://bempp.discourse.group/t/identify-point-to-a-dof-source-drive/161 "2022-12-28T20:38:53Z")

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Hi, I am trying to define a source at a specific vertice of the mesh grid. How can I identify a specific point (x,y,z) to set a specific coefficient (e.g., 1.0+1j\*0.0)? bempp.api.GridFunction(div\_space, coefficients=co…

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## [Issues using GPU](https://bempp.discourse.group/t/issues-using-gpu/146)

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**Author:** [@Gustavo](https://bempp.discourse.group/u/Gustavo)\
**Replies:** 0\
**Last updated:** [19 September 2022 14:51 UTC](https://bempp.discourse.group/t/issues-using-gpu/146 "2022-09-19T14:51:26Z")

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Hi! I’ve currently downloaded on a new machine the latest docker bempp/cl-notebook:latest. However, on this machine, when running bempp I get a segmentation fault. This does not happens with the numba docker image. In…

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## [Modified Green's function](https://bempp.discourse.group/t/modified-greens-function/140)

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**Author:** [@jan](https://bempp.discourse.group/u/jan)\
**Replies:** 1\
**Last updated:** [4 July 2022 13:40 UTC](https://bempp.discourse.group/t/modified-greens-function/140 "2022-07-04T13:40:58Z")

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Hi Matthew and Timo, there is a new problem for me to solve and so a new question for you :slight\_smile: I would like to consider an integral operator which is not implemented yet, so e.g. something like (K\\phi)(x) = …

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## [Sparse Efficiency Warning](https://bempp.discourse.group/t/sparse-efficiency-warning/110)

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**Author:** [@Gustavo](https://bempp.discourse.group/u/Gustavo)\
**Replies:** 2\
**Last updated:** [29 April 2022 12:50 UTC](https://bempp.discourse.group/t/sparse-efficiency-warning/110 "2022-04-29T12:50:27Z")

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Hi, I am totally new to BEMPP and I am still figuring out how to do some stuff. Everytime I ran some code I find here in the Discourse, most of the times I get this warning: SparseEfficiencyWarning: splu requires CSC …

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## [Function for spatial derivative of the potential field](https://bempp.discourse.group/t/function-for-spatial-derivative-of-the-potential-field/134)

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**Author:** [@mospel](https://bempp.discourse.group/u/mospel)\
**Replies:** 1\
**Last updated:** [29 April 2022 12:39 UTC](https://bempp.discourse.group/t/function-for-spatial-derivative-of-the-potential-field/134 "2022-04-29T12:39:52Z")

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Are there functions in BEMPP to calculate the spatial gradient of the potential in a grid function?

[Next page](https://bempp.discourse.group/c/bempp/7.md?page=1)