# Electromagnetics **URL:** https://simpeg.discourse.group/c/electromagnetics/8.md [Latest](https://simpeg.discourse.group/latest.md) · [Categories](https://simpeg.discourse.group/categories.md) --- ## [About the Electromagnetics category](https://simpeg.discourse.group/t/about-the-electromagnetics-category/16)
**Author:** [@lheagy](https://simpeg.discourse.group/u/lheagy)\ **Replies:** 0
This topic is for all things electromagnetics: time-domain, frequency-domain, and natural source methods. --- ## [Empymod compare to Dipole1d](https://simpeg.discourse.group/t/empymod-compare-to-dipole1d/724)
**Author:** [@mhovers](https://simpeg.discourse.group/u/mhovers)\ **Replies:** 0\ **Last updated:** [June 26, 2025, 9:59pm UTC](https://simpeg.discourse.group/t/empymod-compare-to-dipole1d/724 "2025-06-26T21:59:46Z")
I am trying to compare empymod to Kerry Key’s Dipole1d and having mismatches that I am sure are due to my misuse of empymod. Is there a way I can upload an exampe Jupyter notebook with the example? thanks Mike Hoverste… --- ## [Can I do 2D MT inversion using SimPEG?](https://simpeg.discourse.group/t/can-i-do-2d-mt-inversion-using-simpeg/709)
**Author:** [@liyd02](https://simpeg.discourse.group/u/liyd02)\ **Replies:** 0\ **Last updated:** [April 23, 2025, 9:00am UTC](https://simpeg.discourse.group/t/can-i-do-2d-mt-inversion-using-simpeg/709 "2025-04-23T09:00:21Z")
I want to perform 2D inversion of MT data. However, I cannot find examples under the directory nsem. I’d like to know can SimPEG perform 2D inversion of MT data? If this is the case, how can I do it? Thank you very much. … --- ## [1D RESOLVE Bookpurnong Inversion](https://simpeg.discourse.group/t/1d-resolve-bookpurnong-inversion/136)
**Author:** [@wouterdls](https://simpeg.discourse.group/u/wouterdls)\ **Replies:** 2\ **Last updated:** [January 7, 2025, 8:16pm UTC](https://simpeg.discourse.group/t/1d-resolve-bookpurnong-inversion/136 "2025-01-07T20:16:57Z")
Hi everyone! I’m exploring SimPEG with the 1D RESOLVE Bookpurnong Inversion jupyter notebook. It’s nice, because it is related to my research. However, I cannot reproduce the inversion from the paper. I changed the not… --- ## [Modelling x component in TDEM tutorials](https://simpeg.discourse.group/t/modelling-x-component-in-tdem-tutorials/647)
**Author:** [@Kellett](https://simpeg.discourse.group/u/Kellett)\ **Replies:** 0\ **Last updated:** [December 29, 2024, 9:59pm UTC](https://simpeg.discourse.group/t/modelling-x-component-in-tdem-tutorials/647 "2024-12-29T21:59:55Z")
Hello, I have been looking at the X component in some SkyTEM data collected recently as part of a survey over a landslide in NZ. I was interested in testing some modelling approaches using the SimPEG TDEM tutorials(eg fw… --- ## [Waveform definition](https://simpeg.discourse.group/t/waveform-definition/641)
**Author:** [@glow](https://simpeg.discourse.group/u/glow)\ **Replies:** 0\ **Last updated:** [December 4, 2024, 10:38am UTC](https://simpeg.discourse.group/t/waveform-definition/641 "2024-12-04T10:38:42Z")
Regarding the emission waveform of this transient electromagnetic, how should I redefine it in Simpeg’s waveform definition? Here are some measured parameters, Frequency: 240.0 TIME\_DELAY: -1.7E-6 RAMP\_TIME: 4E-6 RAM… --- ## [3D TDEM Forward Problem about how to extract the fields value](https://simpeg.discourse.group/t/3d-tdem-forward-problem-about-how-to-extract-the-fields-value/630)
**Author:** [@glow](https://simpeg.discourse.group/u/glow)\ **Replies:** 1\ **Last updated:** [November 20, 2024, 9:27am UTC](https://simpeg.discourse.group/t/3d-tdem-forward-problem-about-how-to-extract-the-fields-value/630 "2024-11-20T09:27:23Z")
I want to extract the electric field values on each grid obtained through the direct solver during the TDEM calculation process, and then calculate the final electromagnetic response. However, due to the large matrix of … --- ## [Latest versions for Freq domain EM casing modeling](https://simpeg.discourse.group/t/latest-versions-for-freq-domain-em-casing-modeling/628)
**Author:** [@hovg](https://simpeg.discourse.group/u/hovg)\ **Replies:** 0\ **Last updated:** [November 13, 2024, 5:14pm UTC](https://simpeg.discourse.group/t/latest-versions-for-freq-domain-em-casing-modeling/628 "2024-11-13T17:14:32Z")
I currently use the following: git clone GitHub - simpeg-research/heagy-2021-tle-casing conda init conda env create -f environment.yml conda activate heagy-2021-tle-casing pip uninstall empymod pip install empymod=… --- ## [Analysis step error, not enough memory](https://simpeg.discourse.group/t/analysis-step-error-not-enough-memory/624)
**Author:** [@mhovers](https://simpeg.discourse.group/u/mhovers)\ **Replies:** 0\ **Last updated:** [November 6, 2024, 4:14pm UTC](https://simpeg.discourse.group/t/analysis-step-error-not-enough-memory/624 "2024-11-06T16:14:12Z")
I am using the following steps to setup my Anaconda/python environment to run an FDEM casing model: “git clone GitHub - simpeg-research/heagy-2021-tle-casing” cd heagy-2021-tle-casing set -scipy\<=1.6 in environment.yml … --- ## [VLF fwd and inverse](https://simpeg.discourse.group/t/vlf-fwd-and-inverse/620)
**Author:** [@AlexJ](https://simpeg.discourse.group/u/AlexJ)\ **Replies:** 0\ **Last updated:** [October 30, 2024, 6:41pm UTC](https://simpeg.discourse.group/t/vlf-fwd-and-inverse/620 "2024-10-30T18:41:48Z")
Is it possible to forward model and invert VLF in-phase and quadrature data using simpeg? examples of instruments that collect VLF data are the Geonics EM-16 Geonics Limited - VLF Receivers, and the GEM GSM 19 VLF https… --- ## [TEM 1D inversion](https://simpeg.discourse.group/t/tem-1d-inversion/587)
**Author:** [@aalmpanis](https://simpeg.discourse.group/u/aalmpanis)\ **Replies:** 0\ **Last updated:** [July 2, 2024, 2:39pm UTC](https://simpeg.discourse.group/t/tem-1d-inversion/587 "2024-07-02T14:39:35Z")
I have some field TEM data for 1D inversion and trying to define a RawWaveform (basically to get the field waveform); howver, it gives me this error: → \[114\](file:///C:/Users/au756649/AppData/Local/anaconda3/envs/SimPe… --- ## [The 3D NSEM example does not work](https://simpeg.discourse.group/t/the-3d-nsem-example-does-not-work/586)
**Author:** [@xiehaijun](https://simpeg.discourse.group/u/xiehaijun)\ **Replies:** 2\ **Last updated:** [July 1, 2024, 2:36am UTC](https://simpeg.discourse.group/t/the-3d-nsem-example-does-not-work/586 "2024-07-01T02:36:12Z")
Hello! The plot\_fwd\_nsem\_MTTipper3D example does not work，what is the reason? Thank you very much for your answer！ --- ## [3-D forward modeling of NSEM](https://simpeg.discourse.group/t/3-d-forward-modeling-of-nsem/157)
**Author:** [@Dewei](https://simpeg.discourse.group/u/Dewei)\ **Replies:** 3\ **Last updated:** [April 29, 2024, 3:44am UTC](https://simpeg.discourse.group/t/3-d-forward-modeling-of-nsem/157 "2024-04-29T03:44:36Z")
Hello Thank you so much for the opportunity to use the SimPEG and ask questions! In the plot\_fwd\_nsem\_MTTipper3D example, problem = NSEM.Simulation3DPrimarySecondary( M, survey=survey, solver=Solver, sigma=sig, sigmaP… --- ## [3D forward modeling of NSEM](https://simpeg.discourse.group/t/3d-forward-modeling-of-nsem/574)
**Author:** [@xiehaijun](https://simpeg.discourse.group/u/xiehaijun)\ **Replies:** 0\ **Last updated:** [April 29, 2024, 3:39am UTC](https://simpeg.discourse.group/t/3d-forward-modeling-of-nsem/574 "2024-04-29T03:39:33Z")
Hello Thank you so much for the opportunity to use the SimPEG and ask questions! In the plot\_fwd\_nsem\_MTTipper3D example,the program does not work.The error code is as follows： # # # # # # # # # # # # # # # # # Setup … --- ## [Seeking assistance with three-dimensional forward modeling using electrical sources to fit with one-dimensional analytical solutions](https://simpeg.discourse.group/t/seeking-assistance-with-three-dimensional-forward-modeling-using-electrical-sources-to-fit-with-one-dimensional-analytical-solutions/567)
**Author:** [@xiao\_mi](https://simpeg.discourse.group/u/xiao_mi)\ **Replies:** 0\ **Last updated:** [April 10, 2024, 6:46am UTC](https://simpeg.discourse.group/t/seeking-assistance-with-three-dimensional-forward-modeling-using-electrical-sources-to-fit-with-one-dimensional-analytical-solutions/567 "2024-04-10T06:46:15Z")
Hello, I am a master’s student conducting research on the three-dimensional forward modeling of electromagnetic sources in CSAMT.My excitation source is using an electrical source (LineCurrent), and I am performing forwa… --- ## [About the example of "Heagy et al., 2017 1D FDEM and TDEM inversions"](https://simpeg.discourse.group/t/about-the-example-of-heagy-et-al-2017-1d-fdem-and-tdem-inversions/564)
**Author:** [@tanger](https://simpeg.discourse.group/u/tanger)\ **Replies:** 0\ **Last updated:** [March 30, 2024, 2:13pm UTC](https://simpeg.discourse.group/t/about-the-example-of-heagy-et-al-2017-1d-fdem-and-tdem-inversions/564 "2024-03-30T14:13:54Z")
In the example, in the context of “if plotIt:” in function “run”, the line (about 201): dpredFD = prbFD.dpred(moptTD) before ax1.loglog(… I think it should be moptFD, but not moptTD, because they are inversion solutio… --- ## [Limits of EM Forward Modeling Capabilities](https://simpeg.discourse.group/t/limits-of-em-forward-modeling-capabilities/556)
**Author:** [@BAJames](https://simpeg.discourse.group/u/BAJames)\ **Replies:** 2\ **Last updated:** [March 16, 2024, 5:08pm UTC](https://simpeg.discourse.group/t/limits-of-em-forward-modeling-capabilities/556 "2024-03-16T17:08:32Z")
I am interested in Simpeg but I want to find out if it fits what I want to do. I have created the method I am calling Interferographic TEM (ITEM), applying field interference concepts to do TEM beamforming in the subs… --- ## [3D airborne EM with metallic casing](https://simpeg.discourse.group/t/3d-airborne-em-with-metallic-casing/535)
**Author:** [@geodriz](https://simpeg.discourse.group/u/geodriz)\ **Replies:** 0\ **Last updated:** [December 12, 2023, 5:41pm UTC](https://simpeg.discourse.group/t/3d-airborne-em-with-metallic-casing/535 "2023-12-12T17:41:53Z")
Hi All, I’m currently performing some fwd controlled source EM tests over simple 3D models, and I started with FDEM 3D using the ‘plot\_fwd\_3\_fem\_3d.py’ script, from the SimPEG/tutorials/fdem repository. The results loo… --- ## [FDEM HLEM coplanar loop inversion](https://simpeg.discourse.group/t/fdem-hlem-coplanar-loop-inversion/532)
**Author:** [@AlexJ](https://simpeg.discourse.group/u/AlexJ)\ **Replies:** 0\ **Last updated:** [December 5, 2023, 5:41pm UTC](https://simpeg.discourse.group/t/fdem-hlem-coplanar-loop-inversion/532 "2023-12-05T17:41:24Z")
I am using the example from simpeg github: The example consider a single line of loop-loop EM data at 30kHz with 3 different coil separations \[0.32m, 0.71m, 1.18m\] using Horizontal co-planar orientations (vertical mag… --- ## [3D invreion for 3D Electromagnetics problem](https://simpeg.discourse.group/t/3d-invreion-for-3d-electromagnetics-problem/522)
**Author:** [@wangsihao](https://simpeg.discourse.group/u/wangsihao)\ **Replies:** 0\ **Last updated:** [November 6, 2023, 9:13am UTC](https://simpeg.discourse.group/t/3d-invreion-for-3d-electromagnetics-problem/522 "2023-11-06T09:13:31Z")
Do we have 3D inversion code for 3D Electromagnetics problem currently ? I try to modify the sample code in tutorial to progress a 3D inversion problem of frequency domian. When I run the code , I encountered the problem… --- ## [3D SimPEG for Casing Modeling: cannot import name 'get\_dlf\_points' from 'empymod.transform'](https://simpeg.discourse.group/t/3d-simpeg-for-casing-modeling-cannot-import-name-get-dlf-points-from-empymod-transform/423)
**Author:** [@evan](https://simpeg.discourse.group/u/evan)\ **Replies:** 7\ **Last updated:** [October 26, 2023, 5:01am UTC](https://simpeg.discourse.group/t/3d-simpeg-for-casing-modeling-cannot-import-name-get-dlf-points-from-empymod-transform/423 "2023-10-26T05:01:31Z")
Hi SimPEG developers and users, My colleagues plan to use 3D SimPEG for casing modeling. They tried to install and use it based on the instructions found at GitHub - simpeg-research/heagy-2021-tle-casing but faced an er… --- ## [About 2d tdem forward and inversion](https://simpeg.discourse.group/t/about-2d-tdem-forward-and-inversion/504)
**Author:** [@go\_future](https://simpeg.discourse.group/u/go_future)\ **Replies:** 0\ **Last updated:** [September 22, 2023, 10:20am UTC](https://simpeg.discourse.group/t/about-2d-tdem-forward-and-inversion/504 "2023-09-22T10:20:20Z")
I have data collected by the transient electromagnetic method. When I want to use tdem to process it, I encounter that simpeg does not have the tdem 2d forward and inversion module. If simpeg has this module, please tell… --- ## [How to use 3D modeling code for time domain?](https://simpeg.discourse.group/t/how-to-use-3d-modeling-code-for-time-domain/471)
**Author:** [@kanghw](https://simpeg.discourse.group/u/kanghw)\ **Replies:** 2\ **Last updated:** [July 26, 2023, 5:42am UTC](https://simpeg.discourse.group/t/how-to-use-3d-modeling-code-for-time-domain/471 "2023-07-26T05:42:28Z")
Thank you for your dedicated efforts in developing the framework. As a graduate student, I am currently utilizing SimPEG for my research, specifically focusing on studying 3D TDEM modeling code. In my current work, I am… --- ## [Question about 3D Forward Simulation with User-Defined Waveforms](https://simpeg.discourse.group/t/question-about-3d-forward-simulation-with-user-defined-waveforms/448)
**Author:** [@monica](https://simpeg.discourse.group/u/monica)\ **Replies:** 0\ **Last updated:** [May 22, 2023, 9:02am UTC](https://simpeg.discourse.group/t/question-about-3d-forward-simulation-with-user-defined-waveforms/448 "2023-05-22T09:02:57Z")
Hi all, In this example “3D Forward Simulation with User-Defined Waveforms”, how can we set the current or coil size? According to the example, the generated electromagnetic response data ranges from 10^-16 to 10^-11 T… --- ## [Question about forward modeling 1D MT](https://simpeg.discourse.group/t/question-about-forward-modeling-1d-mt/437)
**Author:** [@vicente\_yc](https://simpeg.discourse.group/u/vicente_yc)\ **Replies:** 0\ **Last updated:** [April 24, 2023, 8:15pm UTC](https://simpeg.discourse.group/t/question-about-forward-modeling-1d-mt/437 "2023-04-24T20:15:05Z")
Hello I’m new to the SimPEG library and I’m trying to learn how to use it by starting with a 1D MT forward modeling example. I followed the documentation and based my code on the 3D MT forward modeling example (MT: 3D: … --- ## [SkyTEM response](https://simpeg.discourse.group/t/skytem-response/432)
**Author:** [@p.rani](https://simpeg.discourse.group/u/p.rani)\ **Replies:** 0\ **Last updated:** [April 13, 2023, 5:33am UTC](https://simpeg.discourse.group/t/skytem-response/432 "2023-04-13T05:33:04Z")
HI, I am new to SimPEG. I want to generate 1D forward simulation for skytem system. I am using plot\_fwd\_1\_em1dtm code for forward simulation. However, I am confused about how to put skytem geometry and waveform in this c… --- ## [Possible bug in Electromagnetics frequency domain module](https://simpeg.discourse.group/t/possible-bug-in-electromagnetics-frequency-domain-module/402)
**Author:** [@erlend](https://simpeg.discourse.group/u/erlend)\ **Replies:** 1\ **Last updated:** [January 5, 2023, 9:47am UTC](https://simpeg.discourse.group/t/possible-bug-in-electromagnetics-frequency-domain-module/402 "2023-01-05T09:47:16Z")
Hi, It may be a couple of small bugs in the receivers for the H and B-fields in the electromagnetics module: SimPEG.electromagnetics.frequency\_domain.receivers.PointMagneticFluxDensitySecondary gives the same real pa… --- ## [Near-field FDEM Surface Anomaly](https://simpeg.discourse.group/t/near-field-fdem-surface-anomaly/384)
**Author:** [@MichaWhale](https://simpeg.discourse.group/u/MichaWhale)\ **Replies:** 1\ **Last updated:** [November 30, 2022, 5:14pm UTC](https://simpeg.discourse.group/t/near-field-fdem-surface-anomaly/384 "2022-11-30T17:14:59Z")
Greeting SIMPEG community, My name is Michael Faran and I am very excited to use the software. I am attempting to solve a certain problem I am currently facing, related to a FDEM 2D problem, similar to the link. I wan… --- ## [PardisoError: Analysis step error, reordering problem](https://simpeg.discourse.group/t/pardisoerror-analysis-step-error-reordering-problem/284)
**Author:** [@Alexey](https://simpeg.discourse.group/u/Alexey)\ **Replies:** 1\ **Last updated:** [August 13, 2022, 1:03am UTC](https://simpeg.discourse.group/t/pardisoerror-analysis-step-error-reordering-problem/284 "2022-08-13T01:03:13Z")
Hello, I get the error “PardisoError: Analysis step error, reordering problem” during predict data for a model: dpred = simulation.dpred(model) What have I not configured? I use plot\_fwd\_3\_tem\_3d.ipynb tutorial of si… --- ## [NSEM.plot\_data\_type](https://simpeg.discourse.group/t/nsem-plot-data-type/339)
**Author:** [@yang](https://simpeg.discourse.group/u/yang)\ **Replies:** 0\ **Last updated:** [June 19, 2022, 1:36am UTC](https://simpeg.discourse.group/t/nsem-plot-data-type/339 "2022-06-19T01:36:43Z")
Hi SimPEG users and developers, I have a question about how to use the plotIsoFreqNSimpedance, plotIsoFreqNSDiff and plotPsudoSectNSimpedance function plotIsoFreqNSimpedance which in the NSEM.utils.plot\_data\_types.I mee… [Next page](https://simpeg.discourse.group/c/electromagnetics/8.md?page=1)