pygplates.ResolvedTopologicalSubSegment

class pygplates.ResolvedTopologicalSubSegment

Bases: instance

The subset of vertices of a reconstructed topological section that contribute to the geometry of a resolved topology.

TopologicalModel, TopologicalSnapshot or resolve_topologies() can be used to generate resolved topologies (such as ResolvedTopologicalLine, ResolvedTopologicalBoundary and ResolvedTopologicalNetwork) which, in turn, reference these ResolvedTopologicalSubSegment instances.

Note

Each ResolvedTopologicalSubSegment instance belongs to a single resolved topology.

In contrast, a ResolvedTopologicalSharedSubSegment instance can be shared by one or more resolved topologies.

__init__(): Raises an exception This class cannot be instantiated from Python

Methods

`__init__`	Raises an exception This class cannot be instantiated from Python
`get_feature`()	Same as `get_topological_section_feature()`.
`get_geometry`()	Same as `get_resolved_geometry()`.
`get_resolved_feature`()	Returns a feature containing the resolved sub-segment geometry.
`get_resolved_geometry`()	Returns the geometry containing the sub-segment vertices.
`get_resolved_geometry_point_features`()	Returns the source feature associated with each point in the `resolved geometry points`.
`get_resolved_geometry_point_velocities`(...)	Returns the velocities of the `resolved geometry points`.
`get_resolved_geometry_points`()	Returns the points of the `resolved geometry`.
`get_sub_segments`()	If this sub-segment is from a topological line `section` then return the child `sub-segments` of the topological line contributing to this sub-segment, otherwise return `None`.
`get_topological_section`()	Returns the topological section that the sub-segment was obtained from.
`get_topological_section_feature`()	Returns the feature referenced by the topological section.
`get_topological_section_geometry`()	Returns the topological section geometry that the sub-segment was obtained from.
`was_geometry_reversed_in_topology`()	Whether a copy of the points in `get_resolved_geometry()` were reversed in order to contribute to the resolved topology that this sub-segment is a part of.

get_feature(): Same as get_topological_section_feature().

Warning

The geometry in the feature is present day geometry - it is NOT reconstructed like get_geometry() is.

See get_resolved_feature() for a resolved feature containing reconstructed geometry.

get_geometry(): Same as get_resolved_geometry().

get_resolved_feature()

Returns a feature containing the resolved sub-segment geometry.

Return type:: Feature

The returned feature contains the resolved geometry.

Note

The returned feature does not contain present-day geometry as is typical of most GPlates features.

In this way the returned feature is similar to a GPlates reconstruction export.

Note

The returned feature should not be reverse reconstructed to present day because the topological section might be a ResolvedTopologicalLine which is a topology and topologies are resolved (not reconstructed).

See also

get_topological_section_feature()

get_resolved_geometry()

Returns the geometry containing the sub-segment vertices.

Return type:: PolylineOnSphere

Note

These are the unreversed vertices. They are in the same order as the geometry of get_topological_section_geometry(). If you need a reversed version of this resolved geometry (eg, due to was_geometry_reversed_in_topology() returning True) then you can use pygplates.PolylineOnSphere(sub_segment.get_resolved_geometry()[::-1]).

See also

was_geometry_reversed_in_topology()

get_resolved_geometry_point_features()

Returns the source feature associated with each point in the resolved geometry points.

Return type:: list of Feature

The motion of each point in the resolved geometry is determined by its source feature. And the source features are the building blocks from which topologies are assembled and resolved.

To associate each source feature with its point (in a sub-segment):

points = sub_segment.get_resolved_geometry_points()
point_features = sub_segment.get_resolved_geometry_point_features()

points_and_features = zip(points, point_features)

for point, feature in points_and_features:
  ...

Added in version 1.0.

get_resolved_geometry_point_velocities([velocity_delta_time=1.0][, velocity_delta_time_type=pygplates.VelocityDeltaTimeType.t_plus_delta_t_to_t][, velocity_units=pygplates.VelocityUnits.kms_per_my][, earth_radius_in_kms=pygplates.Earth.mean_radius_in_kms])

Returns the velocities of the resolved geometry points.

Parameters:

velocity_delta_time (float) – The time delta used to calculate velocities (defaults to 1 Myr).
velocity_delta_time_type (VelocityDeltaTimeType.t_plus_delta_t_to_t, VelocityDeltaTimeType.t_to_t_minus_delta_t or VelocityDeltaTimeType.t_plus_minus_half_delta_t) – How the two velocity times are calculated relative to the reconstruction time. This includes [t+dt, t], [t, t-dt] and [t+dt/2, t-dt/2]. Defaults to [t+dt, t].
velocity_units (VelocityUnits.kms_per_my or VelocityUnits.cms_per_yr) – whether to return velocities as kilometres per million years or centimetres per year (defaults to kilometres per million years)
earth_radius_in_kms (float) – the radius of the Earth in kilometres (defaults to pygplates.Earth.mean_radius_in_kms)

Return type:

list of Vector3D

To associate each velocity with its point (in a sub-segment):

points = sub_segment.get_resolved_geometry_points()
point_velocities = sub_segment.get_resolved_geometry_point_velocities()

points_and_velocities = zip(points, point_velocities)

for point, velocity in points_and_velocities:
  ...

Added in version 0.50.

get_resolved_geometry_points()

Returns the points of the resolved geometry.

Return type:: list of PointOnSphere

This method is essentially equivalent to:

def get_resolved_geometry_points(resolved_topological_sub_segment):
    return resolved_topological_sub_segment.get_resolved_geometry().get_points()

See also

GeometryOnSphere.get_points()

Added in version 0.50.

get_sub_segments()

If this sub-segment is from a topological line section then return the child sub-segments of the topological line contributing to this sub-segment, otherwise return None.

Return type:: list of ResolvedTopologicalSubSegment, or None

To see if a sub-segment is from a topological line and then iterate over its child sub-segments:

child_sub_segments_of_topological_line_sub_segment = sub_segment.get_sub_segments()
if child_sub_segments_of_topological_line_sub_segment:
    for child_sub_segment in child_sub_segments_of_topological_line_sub_segment:
        child_sub_segment_geometry = child_sub_segment.get_resolved_geometry()
        child_sub_segment_plate_id = child_sub_segment.get_feature().get_reconstruction_plate_id()
else:
    sub_segment_geometry = sub_segment.get_resolved_geometry()
    sub_segment_plate_id = sub_segment.get_feature().get_reconstruction_plate_id()

Note

Each child sub-segment has its own reverse flag indicating whether it was reversed when contributing to this sub-segment. And this sub-segment also has a reverse flag which determines whether it was reversed when contributing to the final boundary topology. So whether a child sub-segment was effectively reversed when contributing to the final boundary topology depends on both reverse flags (of the child sub-segment and this sub-segment). For example, if the child sub-segment was reversed in this sub-segment, and this sub-segment was reversed in the final boundary, then the child sub-segment was not reversed in the final boundary.

Added in version 0.22.

get_topological_section()

Returns the topological section that the sub-segment was obtained from.

Return type:: ReconstructionGeometry

Note

This represents the entire geometry of the topological section, not just the part that contributes to the sub-segment.

Note

If the resolved topology (that this sub-segment is a part of) is a ResolvedTopologicalLine then the topological section will be a ReconstructedFeatureGeometry.

If the resolved topology (that this sub-segment is a part of) is a ResolvedTopologicalBoundary or a ResolvedTopologicalNetwork then the topological section can be either a ReconstructedFeatureGeometry or a ResolvedTopologicalLine.

See also

get_topological_section_feature()

get_topological_section_feature()

Returns the feature referenced by the topological section.

Return type:: Feature

Note

The geometry in the returned feature represents the entire geometry of the topological section, not just the part that contributes to the sub-segment.

Warning

The geometry in the feature is present day geometry - it is NOT reconstructed like get_topological_section_geometry() is.

See get_resolved_feature() for a resolved feature containing reconstructed geometry.

get_topological_section_geometry()

Returns the topological section geometry that the sub-segment was obtained from.

Return type:: PolylineOnSphere

Note

This is the entire geometry of the topological section, not just the part that contributes to the sub-segment.

See also

get_topological_section()

was_geometry_reversed_in_topology()

Whether a copy of the points in get_resolved_geometry() were reversed in order to contribute to the resolved topology that this sub-segment is a part of.

Return type:: bool

Note

A reversed version of the points of get_resolved_geometry() is equivalent sub_segment.get_resolved_geometry().get_points()[::-1].

See also

get_resolved_geometry()