Transfer Function¶

Plot¶

Regression¶

Base¶

EMTF Z File Helpers¶

These methods can possibly be moved under mt_metadata, or mth5

They extract info needed to setup emtf_z files.

aurora.transfer_function.emtf_z_file_helpers.clip_bands_from_z_file(z_path, n_bands_clip, output_z_path=None, n_sensors=5)[source]¶

This function takes a z_file and clips periods off the end of it. It can come in handy sometimes – specifically for manipulating matlab results of synthetic data.

Parameters

z_path: Path or str: path to the z_file to read in and clip periods from
n_periods_clip: integer: how many periods to clip from the end of the zfile
overwrite: bool: whether to overwrite the zfile or rename it
n_sensors

Returns

aurora.transfer_function.emtf_z_file_helpers.get_default_orientation_block(n_ch=5)[source]¶

Helper function used when working with matlab structs which do not have enough info to make headers

Parameters

n_ch: int: number of channels at the station

Returns

orientation_strs: list: List of text strings, one per channel

aurora.transfer_function.emtf_z_file_helpers.make_orientation_block_of_z_file(run_obj, channel_list=None)[source]¶

Replicates emtz z-file metadata about orientation like this: 1 0.00 0.00 tes Hx 2 90.00 0.00 tes Hy 3 0.00 0.00 tes Hz 4 0.00 0.00 tes Ex 5 90.00 0.00 tes Ey

based on this fortran snippet:: write(3, 115) k, orient(1, k), orient(2, k), stname(1: 3), chid(k)

format(i5, 1x, f8.2, 1x, f8.2, 1x, a3, 2x, a6) #Fortran Format

Parameters

run_obj: mth5.groups.master_station_run_channel.RunGroup: Container with metadata about the channels

Returns

output_strings: list (of strings): Each element of the list corresponds to one channel, and is a block of text for the emtf z-file with the channel orientation, name and associated station

aurora.transfer_function.emtf_z_file_helpers.merge_tf_collection_to_match_z_file(aux_data, tf_collection)[source]¶

Currently this is only used for the synthtetic test, but maybe useful for other tests. Given data from a z_file, and a tf_collection, the tf_collection may have several TF estimates at the same frequency from multiple decimation levels. This tries to make a single array as a function of period for all rho and phi

Parameters

aux_data: merge_tf_collection_to_match_z_file: Object representing a z-file
tf_collection: aurora.transfer_function.transfer_function_collection
.TransferFunctionCollection: Object representing the transfer function returnd from the aurora processing

Returns

result: dict of dicts: Keyed by [“rho”, “phi”], below each of these is an [“xy”, “yx”,] entry. The lowest level entries are numpy arrays.

Iter Control¶

follows Gary’s IterControl.m in iris_mt_scratch/egbert_codes-20210121T193218Z-001/egbert_codes/matlabPrototype_10-13-20/TF/classes

class aurora.transfer_function.regression.iter_control.IterControl(max_number_of_iterations=10, max_number_of_redescending_iterations=2, **kwargs)[source]¶

Bases: object

Attributes

continue_redescending
correction_factor: TODO: This is an RME specific property.

Methods

converged(b, b0)

Parameters

property continue_redescending¶

converged(b, b0)[source]¶

Parameters

bcomplex-valued numpy array: the most recent regression estimate
b0complex-valued numpy array: The previous regression estimate

Returns

converged: bool: True of the regression has terminated, False otherwise
Notes:
The variable maximum_change finds the maximum amplitude component of the vector
1-b/b0. Looking at the formula, one might want to cast this instead as
1 - abs(b/b0), however, that will be insensitive to phase changes in b,
which is complex valued. The way it is coded np.max(np.abs(1 - b / b0)) is
correct as it stands.

property correction_factor¶

TODO: This is an RME specific property. Suggest move r0, u0 and this method into an RME-config class.

See notes on usage in transfer_function.regression.helper_functions.rme_beta

Returns

correction_factorfloat: correction factor used for scaling the residual error_variance