Module `gplately.ptt.separate_ridge_transform_segments`

Split the geometries of isochrons and mid-ocean ridges into ridge and transform segments based on each segment’s alignment with the geometry’s stage pole at its time of appearance.

Source code is based on: http://www.gplates.org/docs/pygplates/sample-code/pygplates_split_isochron_into_ridges_and_transforms.html

Functions

def get_stage_rotation_for_reconstructed_geometry(spreading_feature, rotation_model, spreading_time=None, return_left_right_plates=False)

Find the stage rotation of the spreading feature in the frame of reference of its geometry at the spreading time. The stage pole can then be directly geometrically compared to the reconstructed spreading geometry.

Parameters

spreading_feature: Can be a feature with half-stage rotation reconstruction (using left/right plate IDs) or a regular feature with a conjugate plate ID. An example of the former is a mid-ocean ridge, and of the latter an isochron.
rotation_model : pygplates.RotationModel: Rotation model
spreading_time : number, optional: A time at which spreading is happening. For isochrons this should be its time of appearance (ie, when formed at mid-ocean ridge). For mid-ocean ridges this can be any time when the ridge is actively spreading. Defaults to the time of appearance of 'spreading_feature'.
return_left_right_plates : bool, default=False: Also return the left and right plate IDs (as a 3-tuple of (stage rotation, left plate, right plate)). Defaults to False.

Returns

the stage rotation that can be applied to the geometry at the spreading time

NOTE: It has already had transforms to and from the stage pole reference frame applied. So if you get the stage pole from it, using 'get_euler_pole_and_angle()', then it will be the stage pole in the frame of reference of the geometry at the spreading time.

Returns None if 'spreading_feature' does not satisfy requirements of a spreading feature. (ie, have left/right plate IDs or reconstruction/conjugate plate IDs, and have spreading time not in distant past or future, and have non-zero stage rotation from 'spreading_time + 1' to 'spreading_time').

def separate_features_into_ridges_and_transforms(rotation_features_or_model, spreading_features, spreading_feature_types=None, transform_segment_deviation_in_radians=1.2217304763960306)

Split the geometries of isochrons and mid-ocean ridges into ridge and transform segments based on each segment’s alignment with the geometry’s stage pole at its time of appearance.

Parameters

rotation_features_or_model : rotation model or feature collection(s), or list of features, or filename(s): rotation features or model
spreading_features : spreading feature collection(s), or list of features, or filename(s) or any combination of those: spreading features
spreading_feature_types: Only spreading features with a feature type contained in this list are considered. If None then all spreading features are considered.
transform_segment_deviation_in_radians : number: How much a segment can deviate from the stage pole before it's considered a transform segment (in radians).

Returns

2-tuple (list of pygplates.Feature, list of pygplates.Feature): The separated ridge and transform features respectively.

def separate_geometry_into_ridges_and_transforms(stage_rotation, geometry_at_spreading_time, transform_segment_deviation_in_radians=1.2217304763960306)

Split the geometry of an isochron or mid-ocean ridge (at a time when there is spreading) into ridge and transform segments based on each segment’s alignment with the geometry’s stage pole at its time of appearance.

For isochrons the geometry should be at its time of appearance (ie, when formed at mid-ocean ridge). For mid-ocean ridges the geometry can be any time when the ridge is actively spreading.

Parameters

stage_rotation: The stage rotation that can be applied to the geometry at the spreading time. NOTE: It must have already had transforms to and from the stage pole reference frame applied. In other words, if you get the stage pole from it, using 'get_euler_pole_and_angle()', then it should be the stage pole in the frame of reference of the geometry at the spreading time.
geometry_at_spreading_time : number: The polyline (or polygon) at the spreading time.
transform_segment_deviation_in_radians : number: How much a segment can deviate from the stage pole before it's considered a transform segment (in radians).

Returns

2-tuple (list of pygplates.Polyline, list of pygplates.Polyline), None if 'geometry_at_spreading_time' is not a polyline (or polygon): The separated ridge and transform geometries respectively.