# pygplates.calculate_velocities¶

Calculate velocities at a sequence of points assuming movement due to a finite rotation over a time interval.

Parameters: domain_points (Any sequence of PointOnSphere or LatLonPoint or tuple (float,float,float) or tuple (float,float)) – sequence of points at which to calculate velocities finite_rotation (FiniteRotation) – the rotation pole and angle time_interval_in_my (float) – the time interval (in millions of years) that the rotation angle encompasses 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) list of Vector3D

Calculating velocities (in cms/yr) of all points in a ReconstructedFeatureGeometry (generated by reconstruct()):

rotation_model = pygplates.RotationModel(...)

# Get the rotation from 11Ma to 10Ma, and the feature's reconstruction plate ID.
equivalent_stage_rotation = rotation_model.get_rotation(
10, reconstructed_feature_geometry.get_feature().get_reconstruction_plate_id(), 11)

# Get the reconstructed geometry points.
reconstructed_points = reconstructed_feature_geometry.get_reconstructed_geometry().get_points()

# Calculate a velocity for each reconstructed point over the 1My time interval.
velocities = pygplates.calculate_velocities(
reconstructed_points,
equivalent_stage_rotation,
1,
pygplates.VelocityUnits.cms_per_yr)


Note

Velocities can be converted from global cartesian vectors to local (magnitude, azimuth, inclination) coordinates using pygplates.LocalCartesian.convert_from_geocentric_to_magnitude_azimuth_inclination().

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