A single-frequency inversion (sEIT container)ΒΆ

Full processing of one frequency of one timestep of the data from Weigand and Kemna 2017 (Biogeosciences).

This example uses the sEIT container to load multi-frequency data from the original measurement data.

imports

import os

import numpy as np

import reda
import reda.utils.geometric_factors as geom_facs
from reda.utils.fix_sign_with_K import fix_sign_with_K
import reda.importers.eit_fzj as eit_fzj

define an output directory for all files

output_directory = 'output_single_freq_inversion_sEIT'

import the sEIT data set

seit = reda.sEIT()
seit.import_eit_fzj(
    'data/bnk_raps_20130408_1715_03_einzel.mat',
    'data/configs.dat'
)
Constructing four-point measurements
Summary:
                  a             b  ...     frequency          rpha
count  67375.000000  67375.000000  ...  67375.000000  67375.000000
mean      17.907532     20.831169  ...   2577.580109    473.723981
std       10.333167     10.677015  ...   8258.716055   2729.735973
min        1.000000      2.000000  ...      0.462963  -3141.592649
25%       10.000000     12.000000  ...     29.411765  -3131.399200
50%       17.000000     22.000000  ...    122.222220      5.510219
75%       27.000000     30.000000  ...    700.000000   3139.297772
max       37.000000     38.000000  ...  45000.000000   3141.592652

[8 rows x 7 columns]
with reda.CreateEnterDirectory(output_directory):
    # export the data into CRTomo-style data files. Each frequency gets its own
    # file
    seit.export_to_crtomo_multi_frequency('result_raw_data')

    # just for demonstration purposes, data could be imported from this
    # directory:
    # create a new sEIT container
    seit_temp = reda.sEIT()
    seit_temp.import_crtomo('result_raw_data')
    # delete it to prevent any confusions
    del(seit_temp)
Summary:
                  a             b  ...     frequency          rpha
count  67375.000000  67375.000000  ...  67375.000000  67375.000000
mean      17.907532     20.831169  ...   2577.580109    473.723981
std       10.333167     10.677015  ...   8258.716055   2729.735973
min        1.000000      2.000000  ...      0.462963  -3141.592649
25%       10.000000     12.000000  ...     29.411765  -3131.399201
50%       17.000000     22.000000  ...    122.222220      5.510219
75%       27.000000     30.000000  ...    700.000000   3139.297772
max       37.000000     38.000000  ...  45000.000000   3141.592652

[8 rows x 7 columns]

this is a container measurement, we need to compute geometric factors using numerical modeling Note that this only work if CRMod is available

settings = {
    'rho': 100,
    'elem': 'data/elem.dat',
    'elec': 'data/elec.dat',
    'sink_node': '6467',
    '2D': True,
}
k = geom_facs.compute_K_numerical(seit.data, settings)
seit.data = geom_facs.apply_K(seit.data, k)
fix_sign_with_K(seit.data)
SETTINGS
{'rho': 100, 'elem': 'data/elem.dat', 'elec': 'data/elec.dat', 'sink_node': '6467', '2D': True}
2D modeling

apply correction factors, as described in Weigand and Kemna, 2017 BG

corr_facs_nor = np.loadtxt('data/corr_fac_avg_nor.dat')
corr_facs_rec = np.loadtxt('data/corr_fac_avg_rec.dat')
corr_facs = np.vstack((corr_facs_nor, corr_facs_rec))
seit.data, cfacs = eit_fzj.apply_correction_factors(seit.data, corr_facs)

apply some filters import IPython IPython.embed()

seit.filter('r < 0')
seit.filter('rho_a < 15 or rho_a > 35')
seit.filter('rpha < - 40 or rpha > 3')
seit.filter('rphadiff < -5 or rphadiff > 5')
seit.filter('k > 400')
seit.filter('rho_a < 0')
seit.filter('a == 12 or b == 12 or m == 12 or n == 12')
seit.filter('a == 13 or b == 13 or m == 13 or n == 13')

# seit.filter_incomplete_spectra(flimit=300, percAccept=85)
seit.print_data_journal()
seit.print_log()
--- Data Journal Start ---
2025-11-17 10:29:00.792473
A filter was applied with query "r < 0". In total 543 records were removed
A filter was applied with query "rho_a < 15 or rho_a > 35". In total 13919 records were removed
A filter was applied with query "rpha < - 40 or rpha > 3". In total 10016 records were removed
A filter was applied with query "rphadiff < -5 or rphadiff > 5". In total 14451 records were removed
A filter was applied with query "k > 400". In total 3619 records were removed
A filter was applied with query "rho_a < 0". In total 0 records were removed
A filter was applied with query "a == 12 or b == 12 or m == 12 or n == 12". In total 1003 records were removed
A filter was applied with query "a == 13 or b == 13 or m == 13 or n == 13". In total 934 records were removed
--- Data Journal End ---

2025-11-17 10:29:00,744 - reda.main.logger - INFO - Data sized changed from 67375 to 66832
2025-11-17 10:29:00,754 - reda.main.logger - INFO - Data sized changed from 66832 to 52913
2025-11-17 10:29:00,761 - reda.main.logger - INFO - Data sized changed from 52913 to 42897
2025-11-17 10:29:00,769 - reda.main.logger - INFO - Data sized changed from 42897 to 28446
2025-11-17 10:29:00,774 - reda.main.logger - INFO - Data sized changed from 28446 to 24827
2025-11-17 10:29:00,780 - reda.main.logger - INFO - Data sized changed from 24827 to 24827
2025-11-17 10:29:00,786 - reda.main.logger - INFO - Data sized changed from 24827 to 23824
2025-11-17 10:29:00,792 - reda.main.logger - INFO - Data sized changed from 23824 to 22890

export normal data to volt.dat file note that this is not required for the subsequent code and could be completely removed !!!

with reda.CreateEnterDirectory(output_directory):
    seit.export_to_crtomo_one_frequency('volt.dat', 70.0, 'nor')

alternatively: directly create a tdman object that represents a single-frequency inversion with CRTomo

import crtomo
grid = crtomo.crt_grid('data/elem.dat', 'data/elec.dat')
tdman = seit.export_to_crtomo_td_manager(grid, frequency=70.0, norrec='nor')

# set inversion settings
tdman.crtomo_cfg['robust_inv'] = 'F'
tdman.crtomo_cfg['mag_abs'] = 0.012
tdman.crtomo_cfg['mag_rel'] = 0.5
tdman.crtomo_cfg['hom_bg'] = 'T'
tdman.crtomo_cfg['d2_5'] = 0
tdman.crtomo_cfg['fic_sink'] = 'T'
tdman.crtomo_cfg['fic_sink_node'] = 6467

# run the inversion, use the given output directory to store the CRTomo
# directory structure for later use
# only invert if the output directory does not exists
outdir = '{}/tomodir_inversion'.format(output_directory)
if not os.path.isdir(outdir):
    tdman.invert(
        catch_output=False,
        output_directory=outdir,
    )
else:
    tdman.read_inversion_results(outdir)
    print('Statistics of last iteration:')
    print(tdman.inv_stats.iloc[-1])
This grid was sorted using CutMcK. The nodes were resorted!
Rectangular grid found
Attempting inversion in directory: output_single_freq_inversion_sEIT/tomodir_inversion
Using binary: /usr/bin/CRTomo_dev
Calling CRTomo
Inversion attempt finished
Attempting to import the results
Reading inversion results
is robust False
Info: res_m.diag not found: output_single_freq_inversion_sEIT/tomodir_inversion/inv/res_m.diag
/home/runner/work/crtomo_tools/crtomo_tools/examples/02_simple_inversion
Info: ata.diag not found: output_single_freq_inversion_sEIT/tomodir_inversion/inv/ata.diag
/home/runner/work/crtomo_tools/crtomo_tools/examples/02_simple_inversion
Statistics of last iteration:
iteration                3
main_iteration           3
it_type              DC/IP
type                  main
dataRMS             0.9981
magRMS                 0.9
phaRMS                 9.0
lambda               561.3
roughness           0.3254
cgsteps               70.0
nrdata               354.0
steplength             9.0
stepsize          0.000066
l1ratio                NaN
Name: 14, dtype: object

evolution of the inversion

fig = tdman.plot_inversion_evolution()
with reda.CreateEnterDirectory(output_directory):
    fig.savefig('inversion_evolution.png')

# the statistics are stored in a data frame
print(tdman.inv_stats)
print(tdman.inv_stats.columns)
plot 06 single freq inversion sEIT
#############################
0
Empty DataFrame
Columns: [iteration, main_iteration, it_type, type, dataRMS, magRMS, phaRMS, lambda, roughness, cgsteps, nrdata, steplength, stepsize, l1ratio]
Index: []
#############################
1
   iteration  main_iteration it_type  ... steplength  stepsize  l1ratio
1          1               1   DC/IP  ...        1.0    7420.0      NaN
2          2               1   DC/IP  ...        1.0    7340.0      NaN
3          3               1   DC/IP  ...        0.5    3710.0      NaN

[3 rows x 14 columns]
#############################
2
   iteration  main_iteration it_type  ... steplength  stepsize  l1ratio
5          0               2   DC/IP  ...        1.0     11.00      NaN
6          1               2   DC/IP  ...        1.0      9.52      NaN
7          2               2   DC/IP  ...        1.0      9.19      NaN
8          3               2   DC/IP  ...        1.0      9.46      NaN
9          4               2   DC/IP  ...        0.5      4.59      NaN

[5 rows x 14 columns]
#############################
3
    iteration  main_iteration it_type  ... steplength  stepsize  l1ratio
11          0               3   DC/IP  ...        1.0    0.0656      NaN
12          1               3   DC/IP  ...        1.0    0.1060      NaN
13          2               3   DC/IP  ...        0.5    0.0328      NaN

[3 rows x 14 columns]
    iteration  main_iteration it_type  ... steplength     stepsize  l1ratio
0           0               0   DC/IP  ...        NaN          NaN      NaN
1           1               1   DC/IP  ...        1.0  7420.000000      NaN
2           2               1   DC/IP  ...        1.0  7340.000000      NaN
3           3               1   DC/IP  ...        0.5  3710.000000      NaN
4           1               1   DC/IP  ...        8.0  7421.000000      NaN
5           0               2   DC/IP  ...        1.0    11.000000      NaN
6           1               2   DC/IP  ...        1.0     9.520000      NaN
7           2               2   DC/IP  ...        1.0     9.190000      NaN
8           3               2   DC/IP  ...        1.0     9.460000      NaN
9           4               2   DC/IP  ...        0.5     4.590000      NaN
10          2               2   DC/IP  ...        9.0     8.314000      NaN
11          0               3   DC/IP  ...        1.0     0.065600      NaN
12          1               3   DC/IP  ...        1.0     0.106000      NaN
13          2               3   DC/IP  ...        0.5     0.032800      NaN
14          3               3   DC/IP  ...        9.0     0.000066      NaN

[15 rows x 14 columns]
Index(['iteration', 'main_iteration', 'it_type', 'type', 'dataRMS', 'magRMS',
       'phaRMS', 'lambda', 'roughness', 'cgsteps', 'nrdata', 'steplength',
       'stepsize', 'l1ratio'],
      dtype='object')

evolution of data misfits

fig = tdman.plot_eps_data()
fig = tdman.plot_eps_data_hist()

# eps data is found here:
tdman.eps_data
  • iteration: 0, iteration: 1, iteration: 2, iteration: 3
  • iteration: 0, iteration: 1, iteration: 2, iteration: 3
r = tdman.plot.plot_elements_to_ax(
    tdman.a['inversion']['rmag'][-1],
    plot_colorbar=True,
    cmap_name='jet_r',
)
with reda.CreateEnterDirectory(output_directory):
    r[0].savefig('rmag.png', bbox_inches='tight')

r = tdman.plot.plot_elements_to_ax(
    tdman.a['inversion']['rpha'][-1],
    plot_colorbar=True,
    cmap_name='jet_r',
)
with reda.CreateEnterDirectory(output_directory):
    r[0].savefig('rpha_last_it.png', bbox_inches='tight')
  • plot 06 single freq inversion sEIT
  • plot 06 single freq inversion sEIT

Total running time of the script: (3 minutes 30.634 seconds)

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