Development
The custEM toolbox is under steady academic development. Aside from a few exceptions, only one author can spend effort on implementing new features, updating the documentation, tutorials and examples, or resolving issues. It is possible that a few examples or methods might not work properly or that syntax errors occur in different custEM versions, even though we tried to fix as many issues as possible in custEM version 1.0.0.
We kindly ask for apology in such cases and encourage users to report any bugs, which is the most effective way to increase the robustness of custEM. Furthermore, please contact us in case of missing features and we will try to add the corresponding functionalities.
Release notes
18.03.2024 - custEM version 1.5.0
integration of iterative solvers into custEM
smaller bug fixes for MT/AFMAG inversion
27.11.2023 - custEM version 1.4.0
updates for inversion of natural source EM data
updates for scalar magentometer inversion
intermediate merge only, no documentation updates
15.02.2023 - custEM version 1.3.0
master branch update including implementation progress in 2022
improved sensitivity calculations
improved wrapper for interoperation with pyGIMLi
updates for handling inversion of natural source data (MT, AFMAG)
added examples for inversion applications of CSEM data
moved examples to custEM-examples repository
01.03.2022 - custEM version 1.2.0
use superior TetGen version 1.6
syntax adaption of all existing examples and tutorials
implemented efficient algebra for Jacobi calculations
additional practical meshing functionalities to handle real survey data
many updated on custEM wrapper for pyGIMLi to run inversions
further updates on MT postprocessing
30.07.2021 - custEM version 1.1.0
immense progress on inv_tools
efficient explicit Jacobi calculations
efficient threading over multiple frequencies
wrapper to use custEM as forward operator for pyGIMLi
updates on MT postprocessing - needs still testing!
26.04.2021 - custEM version 1.0.0
final updates for custEM version 1.0
resolved a few remaining bugs
overhaul of API doc strings
update of all finished examples
update of tutorials
22.04.2021 - custEM version 0.99.95
pre-release candidate for custEM version 1.0
resolved a couple of remaining bugs
resolved issue to convert new meshes with the same name instead of accidently using the already converted onces if not deleted manually
simplified and updated interpolation mesh generation to work without seperatly spawned processes for more simplicity and robustness
seperate transmitter currents for multiple Tx in time-domain and DC approaches
03.03.2021 - custEM version 0.99.94
manual interpolation matrices implemented
automated receiver-position handling
dg-paramter functions implemented for all approaches as standard
handling of general anisotropic sigma/mu/eps values now user-friendly
natural-source modeling approach debugged and post-processing simplified
added MT Dublin test model and IP examples
option of serial-ordering for avoiding/reducing? random MUMPS crashes
10.02.2021 - custEM version 0.99.93
major development step towards flexibility, user-friendliness and inversion
logger from standard Python logging module added and working very well, need to replace remaining non-logged prints to write proper log files
multiple-transmitter support for all time-domain approaches
electric and magnetic field approaches now support handling multiple frequencies internally in combination with multiple transmitters
optimized performance exploting reused-factorization as best as possible
potential approaches can now be updated quite easy to support this feature as well, if required by users
overhaul of many outdated code parts and related name conventions
28.01.2021 - custEM version 0.99.92
includes custEM version 0.99.91
natural-source modeling approach based on E-field formulation tested
validation against Dublin test model successful, now proper MT class required
better handling of arbitrary source currents, source and observation time for time-stepping approach added
fix of cell-identification bug in RHSAssembly class
started internal support of multiple frequencies instead of looping over several MOD instances handling only a single frequency
further doc-string updates
9.12.2020 - custEM version 0.99.90
removed some minor bugs which still led to crashes in various approaches
doc strings overhaul and minor optimizations of mod, fem, misc sub-modules
test scripts overhaul and test script for time-domain approaches added
proper documentaion of time-domain modeling examples
validation of implementation to consider induced polarization parameters
19.11.2020 - custEM version 0.99.16
summarized updates since v. 0.98, see also gitlab descriptions of commits
main work in this time was spent on applications and time-domain approaches
advanced mesh tools with node and edge markers
pyhed fixed, identical sign conversion
pyhed incorporated as third-party conda package now, not in wrap directory
time stepping approach optimized
rational krylov approach added
inverse fourier transformation based approach added
documentation updated
few syntax changes
12.06.2019 - custEM version 0.98
conda installer added, installation simplified significantly
custEM tests during conda package build enabled
support got FEniCS version older than 2018 disabled
documentation updated
20.05.2019 - custEM version 0.97
alternative tranformation factors for PF E-field tested with help of empymod
compatibility with FEniCS 2019.1
potential approaches now correctly implemented with identical structure (based on E=iw*A + iw*grad*V) (based on H=iw*F + iw*grad*U)
corresponding post_processing adapated
F-U (Tau-Omega) approach added
bugfixes in meshgen and bathy tools
13.03.2019 - custEM version 0.96
lot’s of bugs fixed (overall compatibility with FEniCS 2018.1)
multiple RHS supported for total field approaches and framwork for adding this feature for secondary field approaches already implemented
test, example and tutorial files updated to be again compatible with a this new version of custEM
All provided scripts were tested also with previous versions based on FEniCS 2017.2, but it is heavily recommended to use this newest version with FEnICS 2018 to benefit from the increased performance!
09.01.2019 - custEM version 0.95
version 0.94 included
custEM now compatible with FEniCS 2018.1
Significant performance boost due to parallel HDF5 support for FEniCS conda package and new MUMPS version, no matrix size restrictions anymore!
Performance boost due to debugged symmetric MUMPS solver (previous custEM versions were bugged and called the general LU solver)
Full Maxwell equations with displacement currents for E-field approach available, in progress for H-field approach
H-field approach debugged
Time-domain time-stepping approach added (not fully supported yet)
Bathymetry/Topography meshing tools improved
Irregular topography data supported
28.08.2018 - custEM version 0.93
bug for primary E-fields of line sources fixed!
alternative and superior way of incorporating transmitters in meshes added
examples 2 reworked
first steps for meshing costal areas with topography, bathymetry initialized
28.08.2018 - custEM version 0.92
ReadtheDocs bug fixed: API for modules added!
restructured repository (custEM modules now subdirectory of repository)
examples added to table of contents
23.08.2018 - custEM version 0.91
fixed sorting-bug workaround for primary-field calculations!
removed minor bugs in meshgen submodule
added topography meshing tutorial to the tutorials directory
enabled edge preservation by using not only .poly but also .edge files for TetGen which is especially an advantage for implementing all kind of CSEM transmitters. As a consequence, TetGen does not need to be called with the ‘-M’ flag anymore for edge preservation, which saves up to 30% of dofs!
Summary of main features before 09.08.2018
documentation added:
documentation of main page, installation notes, etc. added
3 test scripts provided (tests directory)
4 examples provided for reproducibility (examples directory)
3 tutorials for meshing, FE computation and visualization available
automatically updated online documentation on readthedocs.io
six approaches with arbitrary anisotropic conductivities supported for finite element modeling of CSEM problems in frequency domain:
Total and Secondary E-field: E_t and E_s
Secondary H-field: H_s
Total and Secondary A-Phi on mixed elements: Am_t and Am_s
Total and Secondary A-Phi on nodal elements: An_s (only xyz-directed anisotropy supported until now, extension possible)
automated post-processing
meshgen tools robustly implemented for land-based or airborne CSEM setups:
full-space, half-space or layered-earth tetrahedral meshes
topography can be applied to any horizontal surface or interface
transmitters or observation lines on surface shifted automatically to follow topography if required
domain markers applied automatically and imported for computation from MOD instance.
arbitrary anomalies within layers or reaching the surface, several regularly shaped bodies pre-defined
enclosing tetrahedral mesh to increase domain size and minimize boundary artifacts
interpolation on lines or slices:
lines or slices parallel to coordinate axes
crooked “horizontal” lines or slices following topography
multi-threading applied to speed up interpolation
visualization of line or slice data:
automated line or slice plots of all electric or magnetic field components
misfit calculations and visualization
flexible generation of plots with patches combining various data