chaosmagpy.chaos.load_gufm1_txtfile

chaosmagpy.chaos.load_gufm1_txtfile(filepath, name=None)[source]

Load model parameter file of the gufm1 model.

Parameters:
filepathstr

Path to TXT-file (provided by the modellers).

namestr, optional

User defined name of the model. Defaults to the filename without the file extension.

Returns:
modelBaseModel

Class BaseModel instance.

References

For details on the gufm1 model, see the original publication:

Andrew Jackson, Art R. T. Jonkers and Matthew R. Walker (2000), “Four centuries of geomagnetic secular variation from historical records”, Phil. Trans. R. Soc. A.358957–990, http://doi.org/10.1098/rsta.2000.0569

Examples

Load the model and plot the degree-1 secular variation. Here, the model parameter file, e.g. “gufm1”, is in the current working directory.

import chaosmagpy as cp
import matplotlib.pyplot as plt
import numpy as np

model = cp.load_gufm1_txtfile('gufm1')  # load model TXT-file

fig, ax = plt.subplots(1, 1, figsize=(10, 6))

# sample model timespan 7.5 years away from endpoints
time = np.linspace(1590., 1990., 1000)  # decimal years
mjd = cp.data_utils.dyear_to_mjd(time, leap_year=False)

coeffs = model.synth_coeffs(mjd, nmax=1, deriv=1)

ax.plot(time, coeffs)
ax.set_title(model.name)
ax.set_xlabel('Time (years)')
ax.set_ylabel('nT/yr')

ax.legend(['$g_1^0$', '$g_1^1$', '$h_1^1$'])

plt.tight_layout()
plt.show()