gnome.movers

__init__.py for the gnome.movers package

Submodules

• gnome.movers.c_current_movers
• gnome.movers.c_wind_movers
• gnome.movers.movers
• gnome.movers.py_current_movers
• gnome.movers.py_wind_movers
• gnome.movers.random_movers
• gnome.movers.ship_drift_mover
• gnome.movers.simple_mover
• gnome.movers.vertical_movers

Attributes

mover_schemas

Classes

Mover	Base class from which all Python movers/weatherers can inherit
Process	Base class from which all Python movers/weatherers can inherit
CyMover	Base class from which all Python movers/weatherers can inherit
PyMover	Base class from which all Python movers/weatherers can inherit
SimpleMover	simple_mover
PointWindMover	Python wrapper around the Cython wind_mover module.
c_GridWindMover	Base class from which all Python movers/weatherers can inherit
IceWindMover	Base class from which all Python movers/weatherers can inherit
ShipDriftMover	Base class from which all Python movers/weatherers can inherit
RandomMover	"Random Walk" diffusion mover
IceAwareRandomMover	"Random Walk" diffusion mover
RandomMover3D	This mover class inherits from CyMover and contains CyRandomMover3D
CatsMover	Base class from which all Python movers/weatherers can inherit
ComponentMover	Base class from which all Python movers/weatherers can inherit
c_GridCurrentMover	Base class from which all Python movers/weatherers can inherit
IceMover	Base class from which all Python movers/weatherers can inherit
CurrentCycleMover	Base class from which all Python movers/weatherers can inherit
RiseVelocityMover	This mover class inherits from CyMover and contains CyRiseVelocityMover
TamocRiseVelocityMover	The only thing this adds (so far)
WindMover	WindMover implemented in Python. Uses the .wind attribute to move particles.
CurrentMover	CurrentMover implemented in Python. Uses the .current attribute to move particles.

Functions

constant_point_wind_mover(speed, direction[, units])	utility function to create a point wind mover with a constant wind
point_wind_mover_from_file(filename, **kwargs)	Creates a wind mover from a wind time-series file (OSM long wind format)

Package Contents

class gnome.movers.Mover(on=True, make_default_refs=True, active_range=(InfDateTime('-inf'), InfDateTime('inf')), _automanaged=True, **kwargs)

Bases: Process

Base class from which all Python movers/weatherers can inherit

It defines the base functionality for mover/weatherer.

NOTE: Since base class is not Serializable, it does not need

a class level _schema attribute.

Initialize default Mover/Weatherer parameters

All parameters are optional (kwargs)

Parameters:

• on – boolean as to whether the object is on or not. Default is on

• active_range (2-tuple of datetimes) – Range of datetimes for when the mover should be active

get_move(sc, time_step, model_time_datetime)

Compute the move in (long,lat,z) space. It returns the delta move for each element of the spill as a numpy array of size (number_elements X 3) and dtype = gnome.basic_types.world_point_type

Base class returns an array of numpy.nan for delta to indicate the get_move is not implemented yet.

Each class derived from Mover object must implement it’s own get_move

Parameters:

• sc – an instance of gnome.spill_container.SpillContainer class

• time_step – time step in seconds

• model_time_datetime – current model time as datetime object

All movers must implement get_move() since that’s what the model calls

get_bounds()

Return a bounding box surrounding the grid data.

class gnome.movers.Process(on=True, make_default_refs=True, active_range=(InfDateTime('-inf'), InfDateTime('inf')), _automanaged=True, **kwargs)

Bases: gnome.GnomeId

Base class from which all Python movers/weatherers can inherit

It defines the base functionality for mover/weatherer.

NOTE: Since base class is not Serializable, it does not need

a class level _schema attribute.

Initialize default Mover/Weatherer parameters

All parameters are optional (kwargs)

Parameters:

• on – boolean as to whether the object is on or not. Default is on

• active_range (2-tuple of datetimes) – Range of datetimes for when the mover should be active

on = True

make_default_refs = True

property active

property active_range

datetime_to_seconds(model_time)

Put the time conversion call here - in case we decide to change it, it only updates here

prepare_for_model_run()

Override this method if a derived mover class needs to perform any actions prior to a model run

prepare_for_model_step(sc, time_step, model_time_datetime)

sets active flag based on time_span and on flag. Object is active if following hold and ‘on’ is True:

1. active start <= (model_time + time_step/2) so object is on for more than half the timestep

2. (model_time + time_step/2) <= active_stop so again the object is on for at least half the time step flag to true.

Parameters:

• sc – an instance of gnome.spill_container.SpillContainer class

• time_step – time step in seconds

• model_time_datetime – current model time as datetime object

model_step_is_done(sc=None)

This method gets called by the model when after everything else is done in a time step. Put any code need for clean-up, etc in here in subclassed movers.

post_model_run()

Override this method if a derived class needs to perform any actions after a model run is complete (StopIteration triggered)

property data_start

property data_stop

class gnome.movers.CyMover(**kwargs)

Bases: Mover

Base class from which all Python movers/weatherers can inherit

It defines the base functionality for mover/weatherer.

NOTE: Since base class is not Serializable, it does not need

a class level _schema attribute.

Base class for python wrappers around cython movers. Uses super(CyMover, self).__init__(**kwargs) to call Mover class __init__ method

All cython movers (CyWindMover, CyRandomMover) are instantiated by a derived class, and then contained by this class in the member ‘movers’. They will need to extract info from spill object.

We assumes any derived class will instantiate a ‘mover’ object that has methods like: prepare_for_model_run, prepare_for_model_step,

All kwargs passed on to super class

model_time = 0

positions

delta

status_codes

spill_type = 0

prepare_for_model_run()

Calls the contained cython mover’s prepare_for_model_run()

prepare_for_model_step(sc, time_step, model_time_datetime)

Default implementation of prepare_for_model_step(…)

• Sets the mover’s active flag if time is within specified timespan (done in base class Mover)

• Invokes the cython mover’s prepare_for_model_step

Parameters:

• sc – an instance of gnome.spill_container.SpillContainer class

• time_step – time step in seconds

• model_time_datetime – current model time as datetime object

Uses super to invoke Mover class prepare_for_model_step and does a couple more things specific to CyMover.

get_move(sc, time_step, model_time_datetime)

Base implementation of Cython wrapped C++ movers Override for things like the PointWindMover since it has a different implementation

Parameters:

• sc – spill_container.SpillContainer object

• time_step – time step in seconds

• model_time_datetime – current model time as datetime object

prepare_data_for_get_move(sc, model_time_datetime)

organizes the spill object into inputs for calling with Cython wrapper’s get_move(…)

Parameters:

• sc – an instance of gnome.spill_container.SpillContainer class

• model_time_datetime – current model time as datetime object

model_step_is_done(sc=None)

This method gets called by the model after everything else is done in a time step, and is intended to perform any necessary clean-up operations. Subclassed movers can override this method.

class gnome.movers.PyMover(default_num_method='RK2', **kwargs)

Bases: Mover

Base class from which all Python movers/weatherers can inherit

It defines the base functionality for mover/weatherer.

NOTE: Since base class is not Serializable, it does not need

a class level _schema attribute.

Initialize default Mover/Weatherer parameters

All parameters are optional (kwargs)

Parameters:

• on – boolean as to whether the object is on or not. Default is on

• active_range (2-tuple of datetimes) – Range of datetimes for when the mover should be active

num_methods

default_num_method = 'RK2'

delta_method(method_name=None)

Returns a delta function based on its registered name

Usage: delta = self.delta_method(‘RK2’)(**kwargs)

Note: We do not handle any key errors resulting from passing in a bad registered name.

get_delta_Euler(sc, time_step, model_time, pos, vel_field)

get_delta_RK2(sc, time_step, model_time, pos, vel_field)

get_delta_RK4(sc, time_step, model_time, pos, vel_field)

class gnome.movers.SimpleMover(velocity=0, uncertainty_scale=0.5, **kwargs)

Bases: gnome.movers.Mover

simple_mover

a really simple mover – moves all LEs a constant speed and direction

(not all that different than a constant wind mover, now that I

think about it)

simple_mover (velocity)

create a simple_mover instance

Parameters:

• velocity – a (u, v, w) triple – in meters per second

• uncertainty_scale=0.5 – the scale of the uncertainty of the velocity

Remaining kwargs are passed onto Mover’s __init__ using super. See Mover documentation for remaining valid kwargs.

velocity

uncertainty_scale = 0.5

get_move(spill, time_step, model_time)

moves the particles defined in the spill object

Parameters:

• spill – spill is an instance of the gnome.spills.Spill class

• time_step – time_step in seconds

• model_time – current model time as a datetime object

In this case, it uses the positions and status_code data arrays.

Returns delta:

Nx3 numpy array of movement – in (long, lat, meters) units

class gnome.movers.PointWindMover(wind=None, **kwargs)

Bases: WindMoversBase

Python wrapper around the Cython wind_mover module. This class inherits from CyMover and contains CyWindMover

The real work is done by the CyWindMover object. CyMover sets everything up that is common to all movers.

Uses super to call CyMover base class __init__

Parameters:

wind – wind object – provides the wind time series for the mover

Remaining kwargs are passed onto WindMoversBase __init__ using super. See Mover documentation for remaining valid kwargs.

Note

Can be initialized with wind=None; however, wind must be set before running. If wind is not None, toggle make_default_refs to False since user provided a valid Wind and does not wish to use the default from the Model.

mover

property wind

property data_start

property data_stop

prepare_for_model_run()

if wind attribute is not set, raise ReferencedObjectNotSet excpetion

gnome.movers.constant_point_wind_mover(speed, direction, units='m/s')

utility function to create a point wind mover with a constant wind

Parameters:

• speed – wind speed

• direction – wind direction in degrees true (direction from, following the meteorological convention)

• units='m/s' – the units that the input wind speed is in. options: ‘m/s’, ‘knot’, ‘mph’, others…

Returns:

returns a gnome.movers.WindMover object all set up.

Note

The time for a constant wind timeseries is irrelevant. This function simply sets it to datetime.now() accurate to hours.

gnome.movers.point_wind_mover_from_file(filename, **kwargs)

Creates a wind mover from a wind time-series file (OSM long wind format)

Parameters:

• filename – The full path to the data file

• kwargs – All keyword arguments are passed on to the WindMover constructor

Returns mover:

returns a wind mover, built from the file

class gnome.movers.c_GridWindMover(filename=None, topology_file=None, extrapolate=False, time_offset=0, **kwargs)

Bases: WindMoversBase

Base class from which all Python movers/weatherers can inherit

It defines the base functionality for mover/weatherer.

NOTE: Since base class is not Serializable, it does not need

a class level _schema attribute.

Parameters:

• wind_file – file containing wind data on a grid

• filename – file containing wind data on a grid

• topology_file – Default is None. When exporting topology, it is stored in this file

• wind_scale – Value to scale wind data

• extrapolate – Allow current data to be extrapolated before and after file data

• time_offset – Time zone shift if data is in GMT

Pass optional arguments to base class uses super: super(c_GridWindMover,self).__init__(**kwargs)

mover

name

define as property in base class so all objects will have a name by default

filename = None

topology_file = None

property data_start

property data_stop

wind_scale

extrapolate

time_offset

get_grid_data()

get_cells()

Invokes the GetCellDataHdl method of TimeGridWind_c object. Cross-references point data to get cell coordinates.

get_points()

get_cell_center_points()

Right now the cython mover only gets the triangular center points, so we need to calculate centers based on the cells themselves.

Cells will have the format (tl, tr, bl, br) We need to get the rectangular centers Center will be: (tl + ((br - tl) / 2.))

get_center_points()

get_scaled_velocities(time)

Parameters:

model_time=0

export_topology(topology_file)

Parameters:

topology_file=None – absolute or relative path where topology file will be written.

extrapolate_in_time(extrapolate)

Parameters:

extrapolate=false – Allow current data to be extrapolated before and after file data.

offset_time(time_offset)

Parameters:

offset_time=0 – Allow data to be in GMT with a time zone offset (hours).

class gnome.movers.IceWindMover(filename=None, topology_file=None, extrapolate=False, time_offset=0, **kwargs)

Bases: WindMoversBase

Base class from which all Python movers/weatherers can inherit

It defines the base functionality for mover/weatherer.

NOTE: Since base class is not Serializable, it does not need

a class level _schema attribute.

Initialize an IceWindMover

Parameters:

• filename – absolute or relative path to the data file: could be netcdf or filelist

• topology_file=None – absolute or relative path to topology file. If not given, the IceMover will compute the topology from the data file.

• active_range (2-tuple of datetimes) – Range of datetimes for when the mover should be active

• wind_scale – Value to scale wind data

• extrapolate – Allow current data to be extrapolated before and after file data

• time_offset – Time zone shift if data is in GMT

uses super, super(IceWindMover,self).__init__(**kwargs)

name

define as property in base class so all objects will have a name by default

filename = None

topology_file = None

extrapolate = False

get_grid_data()

get_center_points()

get_scaled_velocities(model_time)

Parameters:

model_time=0

get_ice_velocities(model_time)

Parameters:

model_time=0

get_movement_velocities(model_time)

Parameters:

model_time=0

get_ice_fields(model_time)

Parameters:

model_time=0

export_topology(topology_file)

Parameters:

topology_file=None – absolute or relative path where topology file will be written.

extrapolate_in_time(extrapolate)

Parameters:

extrapolate=false – allow current data to be extrapolated before and after file data.

offset_time(time_offset)

Parameters:

offset_time=0 – allow data to be in GMT with a time zone offset (hours).

get_offset_time()

Parameters:

offset_time=0 – allow data to be in GMT with a time zone offset (hours).

class gnome.movers.ShipDriftMover(wind_file=None, topology_file=None, grid_type=1, drift_angle=0, time_offset=0, **kwargs)

Bases: gnome.movers.Mover

Base class from which all Python movers/weatherers can inherit

It defines the base functionality for mover/weatherer.

NOTE: Since base class is not Serializable, it does not need

a class level _schema attribute.

Parameters:

• wind_file – file containing wind data on a grid

• topology_file – Default is None. When exporting topology, it is stored in this file

• wind_scale – Value to scale wind data

• extrapolate – Allow current data to be extrapolated before and after file data

• time_offset – Time zone shift if data is in GMT

Pass optional arguments to base class uses super: super(ShipDriftMover,self).__init__(**kwargs)

wind_file = None

topology_file = None

name

define as property in base class so all objects will have a name by default

drift_angle = 0

grid_type = 1

grid

mover

model_time = 0

positions

delta

status_codes

wind_scale

extrapolate

time_offset

export_topology(topology_file)

Parameters:

topology_file=None – absolute or relative path where topology file will be written.

prepare_for_model_run()

Override this method if a derived mover class needs to perform any actions prior to a model run

prepare_for_model_step(sc, time_step, model_time_datetime)

Call base class method using super Also updates windage for this timestep

Parameters:

• sc – an instance of gnome.spill_container.SpillContainer class

• time_step – time step in seconds

• model_time_datetime – current time of model as a date time object

prepare_data_for_get_move(sc, model_time_datetime)

organizes the spill object into inputs for calling with Cython wrapper’s get_move(…)

Parameters:

• sc – an instance of gnome.spill_container.SpillContainer class

• model_time_datetime – current model time as datetime object

get_move(sc, time_step, model_time_datetime)

Override base class functionality because mover has a different get_move signature

Parameters:

• sc – an instance of the gnome.SpillContainer class

• time_step – time step in seconds

• model_time_datetime – current time of the model as a date time object

model_step_is_done(sc=None)

This method gets called by the model after everything else is done in a time step, and is intended to perform any necessary clean-up operations. Subclassed movers can override this method.

class gnome.movers.RandomMover(diffusion_coef=100000.0, uncertain_factor=2.0, **kwargs)

Bases: gnome.movers.CyMover

“Random Walk” diffusion mover

Moves the elements each time step in a random direction, according to the specified diffusion coefficient.

Parameters:

• diffusion_coef (float or integer in units of cm^2/s) – Diffusion coefficient for random diffusion. Default is 100,000 cm2/sec

• uncertain_factor – Uncertainty factor. Default is 2.0

Remaining kwargs are passed onto gnome.movers.Mover __init__

See Mover documentation for remaining valid kwargs.

mover

property data_start

property data_stop

property diffusion_coef

property uncertain_factor

class gnome.movers.IceAwareRandomMover(ice_concentration=None, **kwargs)

Bases: RandomMover

“Random Walk” diffusion mover

Moves the elements each time step in a random direction, according to the specified diffusion coefficient.

Parameters:

• diffusion_coef (float or integer in units of cm^2/s) – Diffusion coefficient for random diffusion. Default is 100,000 cm2/sec

• uncertain_factor – Uncertainty factor. Default is 2.0

Remaining kwargs are passed onto gnome.movers.Mover __init__

See Mover documentation for remaining valid kwargs.

ice_concentration = None

classmethod from_netCDF(filename=None, dataset=None, grid_topology=None, units=None, time=None, ice_concentration=None, grid=None, grid_file=None, data_file=None, **kwargs)

get_move(sc, time_step, model_time_datetime)

Base implementation of Cython wrapped C++ movers Override for things like the PointWindMover since it has a different implementation

Parameters:

• sc – spill_container.SpillContainer object

• time_step – time step in seconds

• model_time_datetime – current model time as datetime object

class gnome.movers.RandomMover3D(vertical_diffusion_coef_above_ml=5, vertical_diffusion_coef_below_ml=0.11, horizontal_diffusion_coef_above_ml=100000, horizontal_diffusion_coef_below_ml=126, mixed_layer_depth=10.0, surface_is_allowed=False, **kwargs)

Bases: gnome.movers.CyMover

This mover class inherits from CyMover and contains CyRandomMover3D

The real work is done by CyRandomMover3D. CyMover sets everything up that is common to all movers.

Parameters:

• vertical_diffusion_coef_above_ml – Vertical diffusion coefficient for random diffusion above the mixed layer. Default is 5 cm2/s

• vertical_diffusion_coef_below_ml – Vertical diffusion coefficient for random diffusion below the mixed layer. Default is .11 cm2/s

• mixed_layer_depth – Mixed layer depth. Default is 10 meters

• horizontal_diffusion_coef_above_ml – Horizontal diffusion coefficient for random diffusion above the mixed layer. Default is 100000 cm2/s

• horizontal_diffusion_coef_below_ml – Horizontal diffusion coefficient for random diffusion below the mixed layer. Default is 126 cm2/s

• surface_is_allowed – Vertical diffusion will ignore surface particles if this is True. Default is False.

Remaining kwargs are passed onto Mover’s __init__ using super.

See Mover documentation for remaining valid kwargs.

mover

property horizontal_diffusion_coef_above_ml

property horizontal_diffusion_coef_below_ml

property vertical_diffusion_coef_above_ml

property vertical_diffusion_coef_below_ml

property mixed_layer_depth

property surface_is_allowed

class gnome.movers.CatsMover(filename=None, tide=None, uncertain_duration=48, **kwargs)

Bases: CurrentMoversBase

Base class from which all Python movers/weatherers can inherit

It defines the base functionality for mover/weatherer.

NOTE: Since base class is not Serializable, it does not need

a class level _schema attribute.

Uses super to invoke base class __init__ method.

Parameters:

filename – file containing currents patterns for Cats

Optional parameters (kwargs). Defaults are defined by CyCatsMover object.

Parameters:

• tide – a gnome.environment.Tide object to be attached to CatsMover

• scale – a boolean to indicate whether to scale value at reference point or not

• scale_value – value used for scaling at reference point

• scale_refpoint – reference location (long, lat, z). The scaling applied to all data is determined by scaling the raw value at this location.

• uncertain_duration – how often does a given uncertain element gets reset

• uncertain_time_delay – when does the uncertainly kick in.

• up_cur_uncertain – Scale for uncertainty along the flow

• down_cur_uncertain – Scale for uncertainty along the flow

• right_cur_uncertain – Scale for uncertainty across the flow

• left_cur_uncertain – Scale for uncertainty across the flow

• uncertain_eddy_diffusion – Diffusion coefficient for eddy diffusion. Default is 0.

• uncertain_eddy_v0 – Default is .1 (Check that this is still used)

Remaining kwargs are passed onto Mover’s __init__ using super. See Mover documentation for remaining valid kwargs.

mover

up_cur_uncertain

down_cur_uncertain

right_cur_uncertain

left_cur_uncertain

uncertain_eddy_diffusion

uncertain_eddy_v0

scale

scale_value

filename

property ref_scale

property scale_refpoint

property tide

property data_start

property data_stop

get_grid_data()

Invokes the GetToplogyHdl method of TriGridVel_c object

get_center_points()

get_scaled_velocities(model_time)

Get file values scaled to ref pt value, with tide applied (if any)

class gnome.movers.ComponentMover(filename1=None, filename2=None, wind=None, scale_refpoint=None, pat1_angle=0, pat1_speed=10, pat1_speed_units=2, pat1_scale_to_value=0.1, pat2_angle=90, pat2_scale_to_value=0.1, pat2_speed=10, pat2_speed_units=2, scale_by=0, **kwargs)

Bases: CurrentMoversBase

Base class from which all Python movers/weatherers can inherit

It defines the base functionality for mover/weatherer.

NOTE: Since base class is not Serializable, it does not need

a class level _schema attribute.

Uses super to invoke base class __init__ method.

Parameters:

filename – file containing currents for first Cats pattern

Optional parameters (kwargs). Defaults are defined by CyCatsMover object.

Parameters:

• filename – file containing currents for second Cats pattern

• wind – A gnome.environment.Wind object to be used to drive the CatsMovers. Will want a warning that mover will not be active without a wind

• scale – A boolean to indicate whether to scale value at reference point or not

• scale_value – Value used for scaling at reference point

• scale_refpoint – Reference location (long, lat, z). The scaling applied to all data is determined by scaling the raw value at this location.

Remaining kwargs are passed onto Mover’s __init__ using super. See Mover documentation for remaining valid kwargs.

filename1 = None

filename2 = None

mover

scale_by = 0

property scale_refpoint

pat1_angle = 0

pat1_speed = 10

pat1_speed_units = 2

pat1_scale_to_value = 0.1

pat2_angle = 90

pat2_scale_to_value = 0.1

pat2_speed = 10

pat2_speed_units = 2

extrapolate

use_averaged_winds

wind_power_factor

past_hours_to_average

scale_factor_averaged_winds

use_original_scale_factor

property data_start

property data_stop

property wind

get_grid_data()

Invokes the GetToplogyHdl method of TriGridVel_c object

get_center_points()

get_optimize_values(model_time)

get_scaled_velocities(model_time)

Get file values scaled to optimized check if pat2 exists

class gnome.movers.c_GridCurrentMover(filename, topology_file=None, extrapolate=False, time_offset=0, current_scale=1, uncertain_along=0.5, uncertain_across=0.25, uncertain_cross=0.25, num_method='Euler', **kwargs)

Bases: CurrentMoversBase

Base class from which all Python movers/weatherers can inherit

It defines the base functionality for mover/weatherer.

NOTE: Since base class is not Serializable, it does not need

a class level _schema attribute.

Initialize a c_GridCurrentMover

Parameters:

• filename – absolute or relative path to the data file: could be netcdf or filelist

• topology_file=None – absolute or relative path to topology file. If not given, the c_GridCurrentMover will compute the topology from the data file.

• active_range (2-tuple of datetimes) – Range of datetimes for when the mover should be active

• current_scale – Value to scale current data

• uncertain_duration – how often does a given uncertain element get reset

• uncertain_time_delay – when does the uncertainly kick in.

• uncertain_cross – Scale for uncertainty perpendicular to the flow

• uncertain_along – Scale for uncertainty parallel to the flow

• extrapolate – Allow current data to be extrapolated before and after file data

• time_offset – Time zone shift if data is in GMT

• num_method – Numerical method for calculating movement delta. Default Euler option: Runga-Kutta 4 (RK4)

uses super, super(c_GridCurrentMover,self).__init__(**kwargs)

filename

name

define as property in base class so all objects will have a name by default

topology_file = None

current_scale = 1

uncertain_along = 0.5

uncertain_across = 0.25

uncertain_cross = 0.25

property num_method

extrapolate

time_offset

property data_start

property data_stop

property is_data_on_cells

get_grid_data()

The main function for getting grid data from the mover

get_center_points()

get_scaled_velocities(time)

Parameters:

time=0 – model time in integer seconds

export_topology(topology_file)

Parameters:

topology_file=None – absolute or relative path where topology file will be written.

extrapolate_in_time(extrapolate)

Parameters:

extrapolate=false – allow current data to be extrapolated before and after file data.

offset_time(time_offset)

Parameters:

offset_time=0 – allow data to be in GMT with a time zone offset (hours).

get_offset_time()

Parameters:

offset_time=0 – allow data to be in GMT with a time zone offset (hours).

get_start_time()

:this will be the real_data_start time (seconds).

get_end_time()

:this will be the real_data_stop time (seconds).

get_num_method()

class gnome.movers.IceMover(filename=None, topology_file=None, current_scale=1, uncertain_along=0.5, uncertain_cross=0.25, extrapolate=False, time_offset=0, **kwargs)

Bases: CurrentMoversBase

Base class from which all Python movers/weatherers can inherit

It defines the base functionality for mover/weatherer.

NOTE: Since base class is not Serializable, it does not need

a class level _schema attribute.

Initialize an IceMover

Parameters:

• filename – absolute or relative path to the data file: could be netcdf or filelist

• topology_file=None – absolute or relative path to topology file. If not given, the IceMover will compute the topology from the data file.

• active_range (2-tuple of datetimes) – Range of datetimes for when the mover should be active

• current_scale – Value to scale current data

• uncertain_duration – how often does a given uncertain element get reset

• uncertain_time_delay – when does the uncertainly kick in.

• uncertain_cross – Scale for uncertainty perpendicular to the flow

• uncertain_along – Scale for uncertainty parallel to the flow

• extrapolate – Allow current data to be extrapolated before and after file data

• time_offset – Time zone shift if data is in GMT

uses super, super(IceMover,self).__init__(**kwargs)

filename = None

name

define as property in base class so all objects will have a name by default

topology_file = None

extrapolate = False

uncertain_along = 0.5

uncertain_cross = 0.25

current_scale = 1

time_offset

get_grid_data()

get_grid_bounding_box(grid_data=None, box_to_merge=None)

Return a bounding box surrounding the grid data.

Parameters:

• grid_data (A sequence of 3-tuples or 4-tuples containing (long, lat) pairs.) – The point data of our grid.

• box_to_merge – A bounding box to surround in combination with our grid data. This allows us to pad the bounding box that we generate.

get_center_points()

get_scaled_velocities(model_time)

Parameters:

model_time=0 – datetime in integer seconds

get_ice_velocities(model_time)

Parameters:

model_time=0

get_movement_velocities(model_time)

Parameters:

model_time=0

get_ice_fields(model_time)

Parameters:

model_time=0

export_topology(topology_file)

Parameters:

topology_file=None – absolute or relative path where topology file will be written.

extrapolate_in_time(extrapolate)

Parameters:

extrapolate=false – allow current data to be extrapolated before and after file data.

offset_time(time_offset)

Parameters:

offset_time=0 – allow data to be in GMT with a time zone offset (hours).

get_offset_time()

Parameters:

offset_time=0 – allow data to be in GMT with a time zone offset (hours).

class gnome.movers.CurrentCycleMover(filename=None, topology_file=None, tide=None, **kwargs)

Bases: c_GridCurrentMover

Base class from which all Python movers/weatherers can inherit

It defines the base functionality for mover/weatherer.

NOTE: Since base class is not Serializable, it does not need

a class level _schema attribute.

Initialize a CurrentCycleMover

Parameters:

• filename – Absolute or relative path to the data file: could be netcdf or filelist

• topology_file=None – Absolute or relative path to topology file. If not given, the c_GridCurrentMover will compute the topology from the data file.

• tide – A gnome.environment.Tide object to be attached to CatsMover

• active_range (2-tuple of datetimes) – Range of datetimes for when the mover should be active

• current_scale – Value to scale current data

• uncertain_duration – How often does a given uncertain element get reset

• uncertain_time_delay – when does the uncertainly kick in.

• uncertain_cross – Scale for uncertainty perpendicular to the flow

• uncertain_along – Scale for uncertainty parallel to the flow

• extrapolate – Allow current data to be extrapolated before and after file data

• time_offset – Time zone shift if data is in GMT

uses super: super(CurrentCycleMover,self).__init__(**kwargs)

mover

property tide

property data_start

property data_stop

property is_data_on_cells

get_center_points()

get_scaled_velocities(time)

Parameters:

time=0 – datetime in integer seconds

class gnome.movers.RiseVelocityMover(**kwargs)

Bases: gnome.movers.CyMover

This mover class inherits from CyMover and contains CyRiseVelocityMover

The real work is done by CyRiseVelocityMover. CyMover sets everything up that is common to all movers.

Uses super to invoke base class __init__ method.

Optional parameters (kwargs) used to initialize CyRiseVelocityMover

Parameters:

• water_density – Default is 1020 kg/m3

• water_viscosity – Default is 1.e-6

Remaining kwargs are passed onto Mover’s __init__ using super. See Mover documentation for remaining valid kwargs.

mover

get_move(sc, time_step, model_time_datetime)

Override base class functionality because mover has a different get_move signature

Parameters:

• sc – an instance of the gnome.SpillContainer class

• time_step – time step in seconds

• model_time_datetime – current time of the model as a date time object

class gnome.movers.TamocRiseVelocityMover(*args, **kwargs)

Bases: RiseVelocityMover

The only thing this adds (so far)

are droplet_diameter and density array types

Uses super to invoke base class __init__ method.

Optional parameters (kwargs) used to initialize CyRiseVelocityMover

Parameters:

• water_density – Default is 1020 kg/m3

• water_viscosity – Default is 1.e-6

Remaining kwargs are passed onto Mover’s __init__ using super. See Mover documentation for remaining valid kwargs.

class gnome.movers.WindMover(wind=None, uncertain_duration=3.0 * 3600, uncertain_time_delay=0, uncertain_speed_scale=2.0, uncertain_angle_scale=0.4, scale_value=1, default_num_method='RK2', filename=None, **kwargs)

Bases: gnome.movers.movers.PyMover

WindMover implemented in Python. Uses the .wind attribute to move particles. The .at() interface is expected on the .wind attribute

Initialize a WindMover :param wind: Environment object representing wind to be

used.

Parameters:

• active_range (2-tuple of datetimes) – Range of datetimes for when the mover should be active

• scale_value – Value to scale wind data

• uncertain_duration – how often does a given uncertain element get reset

• uncertain_time_delay – when does the uncertainly kick in.

• uncertain_speed_scale – Scale for uncertainty of wind speed

• uncertain_angle_scale – Scale for uncertainty of wind angle

• num_method – Numerical method for calculating movement delta. Choices:(‘Euler’, ‘RK2’, ‘RK4’) Default: RK2

wind = None

make_default_refs = False

uncertain_duration = 10800.0

uncertain_time_delay = 0

uncertain_speed_scale = 2.0

uncertain_angle_scale = 0.4

uncertain_diffusion = 0

scale_value = 1

sigma_theta = 0

sigma2 = 0

is_first_step = False

time_uncertainty_was_set = 0

shape = (2,)

uncertainty_list

classmethod from_netCDF(filename=None, scale_value=1, uncertain_duration=3 * 3600, uncertain_time_delay=0, uncertain_speed_scale=2.0, uncertain_angle_scale=0.4, default_num_method='RK2', **kwargs)

property data_start

property data_stop

prepare_for_model_run()

reset uncertainty

prepare_for_model_step(sc, time_step, model_time_datetime)

Call base class method using super Also updates windage for this timestep

Parameters:

• sc – an instance of gnome.spill_container.SpillContainer class

• time_step – time step in seconds

• model_time_datetime – current time of model as a date time object

model_step_is_done(sc)

remove any off map les

get_bounds()

Return a bounding box surrounding the grid data. This function exists because it is part of the top level Mover API

update_uncertainty(num_les, elapsed_time)

update uncertainty

Parameters:

• num_les – the number released so far

• elapsed_time – time in seconds since model run started

update_uncertainty_values(elapsed_time)

update uncertainty values

Parameters:

elapsed_time – time in seconds since model run started

allocate_uncertainty(num_les)

add uncertainty

Parameters:

num_les – the number of les released so far

add_uncertainty(deltas, time_step)

add uncertainty

Parameters:

deltas – the movement for the current time step

get_move(sc, time_step, model_time_datetime, num_method=None)

Compute the move in (long,lat,z) space. It returns the delta move for each element of the spill as a numpy array of size (number_elements X 3) and dtype = gnome.basic_types.world_point_type

Base class returns an array of numpy.nan for delta to indicate the get_move is not implemented yet.

Each class derived from Mover object must implement it’s own get_move

Parameters:

• sc – an instance of gnome.spill_container.SpillContainer class

• time_step – time step in seconds

• model_time_datetime – current model time as datetime object

All movers must implement get_move() since that’s what the model calls

class gnome.movers.CurrentMover(current=None, scale_value=1, uncertain_duration=24 * 3600, uncertain_time_delay=0, uncertain_along=0.5, uncertain_cross=0.25, default_num_method='RK2', filename=None, **kwargs)

Bases: gnome.movers.movers.PyMover

CurrentMover implemented in Python. Uses the .current attribute to move particles. The .at() interface is expected on the .current attribute

Initialize a CurrentMover

Parameters:

• current (Any Current or Current-like that implements the .at() function) – Environment object representing ocean currents to be used.

• active_range (2-tuple of datetimes) – Range of datetimes for when the mover should be active

• scale_value – Value to scale current data

• uncertain_duration – how often does a given uncertain element get reset in seconds

• uncertain_time_delay – when does the uncertainly kick in in seconds

• uncertain_cross – Scale for uncertainty perpendicular to the flow

• uncertain_along – Scale for uncertainty parallel to the flow

• default_num_method – Numerical method for calculating movement delta. Choices:(‘Euler’, ‘RK2’, ‘RK4’) Default: RK2

property filename

current = None

scale_value = 1

uncertain_along = 0.5

uncertain_cross = 0.25

uncertain_duration = 86400

uncertain_time_delay = 0

model_time = 0

spill_type = 0

is_first_step = False

time_uncertainty_was_set = 0

shape = (2,)

classmethod from_netCDF(filename=None, name=None, scale_value=1, uncertain_duration=24 * 3600, uncertain_time_delay=0, uncertain_along=0.5, uncertain_cross=0.25, **kwargs)

Function for specifically creating a CurrentMover from a file

property data_start

property data_stop

get_bounds()

Return a bounding box surrounding the grid data. This function exists because it is part of the top level Mover API

get_move(sc, time_step, model_time_datetime, num_method=None)

Compute the move in (long,lat,z) space. It returns the delta move for each element of the spill as a numpy array of size (number_elements X 3) and dtype = gnome.basic_types.world_point_type

Base class returns an array of numpy.nan for delta to indicate the get_move is not implemented yet.

Each class derived from Mover object must implement it’s own get_move

Parameters:

• sc – an instance of gnome.spill_container.SpillContainer class

• time_step – time step in seconds

• model_time_datetime – current model time as datetime object

All movers must implement get_move() since that’s what the model calls

prepare_for_model_run()

reset uncertainty

prepare_for_model_step(sc, time_step, model_time_datetime)

add uncertainty

model_step_is_done(sc)

remove any off map les

gnome.movers.mover_schemas