watex.datasets.gdata.make_erp(*, n_stations=42, max_rho=1000.0, min_rho=1.0, step=20.0, reflong='110:29:09.00', reflat='26:03:05.00', utm_zone='29N', order='+', full_coordinates=True, raise_warning=False, as_frame=False, seed=None, **coord_kws)[source]#

Generate Electrical Resistivity Profiling (ERP) data from stations and coordinates points.

To generate samples from specific area, it is better to provide both latitude and longitude values from a single station of this area as arguments passed to parameters reflat and reflong respectively. Also specify the utm_zone for the lat/lon coordinates conversion into UTM if necessary. If not useful, can turn off the parameter full_coordinates to False.

Parameters:

  • n_stations (int, default=42) – number of measurements stations

  • max_rho (float, default=1e3) – maximum resistivity value on the survey area in \(\Omega.m\)

  • min_rho (float, default=1e0) – minimum resistivity value on the survey area in \(\Omega.m\)

  • reflong (float or string or list of [start, stop], default='110:29:09.00') – Reference longitude in degree decimal or in DD:MM:SS for the first station considered as the origin of the landmark.

  • reflat (float or string or list of [start, stop], default='26:03:05.00') – Reference latitude in degree decimal or in DD:MM:SS for the reference site considered as the landmark origin. If value is given in a list, it can contain the start point and the stop point.

  • step (float or str , default=20) – Offset or the distance of seperation between different sites in meters. If the value is given as string type, except the km, it should be considered as a m value. Only meters and kilometers are accepables.

  • order (str , default='-') – Direction of the projection line. By default the projected line is in ascending order i.e. from SW to NE with angle r set to 45 degrees. Could be - for descending order. Any other value should be in ascending order.

  • utm_zone (string (##N or ##S), default='29N') – utm zone in the form of number and North or South hemisphere, 10S or 03N Must be given if utm2deg is set to True.

  • full_coordinates (bool, default=True,) – Convert latitude and longitude to approximate UTM values. Easting and northing are gotten using the reference ellipsoid =23 with WGS84. If False, easting and northing are not computed and set to null.

  • raise_warning (bool, default=True,) –

    Raises warnings if GDAL is not set or the coordinates accurately status.

    as_frame: bool, default=False,

    if True, outputs the data into as a pandas dataframe, Boxspace object otherwise.

  • seed (int, Optional,) – It allows reproducing the same data. If value is passed, it reproduces the same data at that sample points.

  • coord_kws (dict,) – Additional keywords passed to makeCoords().

Return type:

(pd.Dataframe | Boxspace )

Examples

>>> from watex.datasets.gdata import make_erp
>>> erp_data = make_erp (n_stations =50 , step =30  , as_frame =True)
>>> erp_data.head(3)
Out[256]:
   station  longitude  latitude        easting    northing  resistivity
0        0 -13.488511  0.000997  668210.580864  110.183287   225.265306
1       30 -13.488511  0.000997  668210.581109  110.183482   327.204082
2       60 -13.488510  0.000997  668210.581355  110.183676   204.877551
watex.datasets.gdata.make_ves(*, samples=31, min_rho=10.0, max_rho=1000.0, max_depth=100.0, order='-', as_frame=False, seed=None, iorder=3)[source]#

Generate Vertical Electrical Sounding (VES) data from pseudo-depth measurements.

For a large pseudo-depth measurements, one can change the number of samples to a large values. The default samples presumed collected is samples=31 measurements in deeper.

Parameters:

  • samples (int, default=42) – number of measurements depth AB/2 in meters.

  • max_rho (float, default=1e3) – maximum resistivity value expected in deeeper on the survey area in \(\\Omega.m\)

  • min_rho (float, default=1e1) – minimum resistivity value expected in deeper on the survey area in \(\\Omega.m\)

  • order (str , default='-') – Direction of the projection line. By default the projected line is in ascending order i.e. from SW to NE with angle r set to 45 degrees. Could be - for descending order. Any other value should be in ascending order.

  • max_depth (float, default=100) – Value of the measurement in deeper expected to reach by AB/2 in meters.

  • as_frame (bool, default=False,) – if True, outputs the data into as a pandas dataframe, Boxspace object otherwise.

  • seed (int, Optional,) – It allows reproducing the same data. If value is passed, it reproduces the same data at that sample points.

  • iorder (float, default=3) – Inflexion order. If None should compute using the length of extrema (local + global). Must be lower as possible to let the fitting VES curve more realistic.

Return type:

(pd.Dataframe | Boxspace )

Notes

when returning the Boxspace object, each columns of ‘VES’ data can be retrieved as an attributes. Check the examples below

Examples

>>> from watex.datasets.gdata import make_ves
>>> b = make_ves (samples =50 , order ='+') # 50 measurements in deeper
>>> b.resistivity [:-7]
Out[314]:
array([429.873 , 434.255 , 438.5707, 442.8203, 447.0042, 451.1228,
       457.5775])
>>> b.frame.head(3)
Out[315]:
    AB   MN  resistivity
0  1.0  0.6   429.872999
1  2.0  0.6   434.255018
2  3.0  0.6   438.570675