wind package

Submodules

wind.vmax module

vmax – calculate maximum wind speed from pressure deficit

CreationDate: 2006-10-30 Description: Calculate Vmax from pressure difference and vice versa. Offers three relations for calculating Vmax based on the pressure difference - Atkinson & Holliday (1977), Holland (1980) and Willoughby & Rahn (2004). The default is the Holland relation.

The normalisations to 10m AGL, 10-minute-mean winds were taken from Harper (2002).

SeeAlso: (related programs) Constraints: Input pressures should be in Pa (not hPa) Version: $Rev: 810 $

Version: 220 ModifiedBy: Craig Arthur ModifiedDate: 2006-12-01 Modification: Added pDiff function

Version: 267 ModifiedBy: Craig Arthur ModifiedDate: 2007-02-19 Modification: Normalised all vmax relations to provide 10m AGL, 10-minute-mean wind speeds

References

  • Atkinson and Holliday 1977: Tropical Cyclone Minimum Sea Level Pressure / Maximum Sustained Wind Relationship for the Wetern North Pacific. Mon. Wea. Rev., 105, 421-427

  • Holland, G. 1980: An Analytic Model of the Wind and Pressure Profiles in Hurricanes. Mon. Wea. Rev, 108, 1212-1218

  • Willoughby, H.E. and M.E. Rahn, 2004: Parametric Representation of the Primary Hurricane Vortex. Part I: Observations and Evaluation of the Holland (1980) Model. Mon. Wea. Rev., 132, 3033-3048

  • Harper, B.A. 2002: Tropical Cyclone Parameter Estimation in the Australian Region: Wind-Pressure Relationships and Related Issues for Engineering Planning and Design.

$Id: vmax.py 810 2012-02-21 07:52:50Z nsummons $

pDiff(vMax, pEnv, vMaxType='holland', beta=1.3, rho=1.15)

Inverse functions to calculate central pressure from vMax Assumes vMax is given in metres/second. Returns pCentre in Pa.

vmax(pCentre, pEnv, type='holland', beta=1.3, rho=1.15)

Calculate the maximum wind speed from the pressure difference.

Parameters

  • pc (float) – central pressure (Pa)

  • pe (float) – environmental pressure (Pa)

  • type (str) – which Vmax relation to use (Willoughby & Rahn, Holland or Atkinson & Holliday)

  • beta (float) – Holland’s (1980) beta parameter. Only used for the Holland estimation (type=holland)

  • rho (float) – air density (default=1.15 kg/m^3)

Returns

maximum wind speed. For types 1 & 2, this is a gradient level wind. The relation used in type 3 (Atkinson & Holliday) was determined using surface wind observations so should be used with caution at the gradient level.

Raises

ValueError – if environmental pressure is lower than central pressure

Note: The pressure should ideally be passed in units of Pa, but the function will accept hPa and automatically convert to Pa.

wind.windmodels module

This provides classes and methods that calculate the gradient level and surface (10-m above ground) wind speed, based on a number of parametric profiles and boundary layer models. These classes and methods provide the wind field at a single point in time. The complete wind swath is evaluated in the calling classes.

The windmodels.WindSpeedModel classes define the wind-pressure relations that define the maximum wind speed for a given central pressure deficit.

The windmodels.WindProfileModel classes define parametric radial profiles of gradient level wind speed around the primary TC vortex. These do not account for TC motion or interaction with the surface.

The windmodels.WindFieldModel classes define the boundary layer models implemented, which relate the gradient level vortex to the surface wind speed, incorporating the wavenumber-1 assymetry due to storm forward motion, and the effects of (uniform) surface roughness.

Wind speeds are assumed to represent a 1-minute mean wind speed. Conversion to other averaging periods is performed by application of gust factors in the calling classes.

Note

Not all models are fully implemented - some cannot be fully implemented, as the mathematical formulation results in discontinuous profiles (e.g. Rankine vortex), for which a mathematical representation of the vorticity cannot be defined. The vorticity is required for the windmodels.KepertWindFieldModel. Users should carefully select the combinations of wind profiles and wind fields to ensure sensible results.

class AtkinsonWindSpeed(windProfileModel)

Bases: wind.windmodels.WindSpeedModel

Atkinson and Holliday (1977), Tropical Cyclone Minimum Sea Level Pressure / Maximum Sustained Wind Relationship for the Western North Pacific . Mon. Wea. Rev., 105, 421-427 Maximum 10m, 1-minute wind speed. Uses pEnv as 1010 hPa.

maximum()

Maximum wind speed.

class DoubleHollandWindProfile(lat, lon, eP, cP, rMax, beta1, beta2, rMax2=150.0, windSpeedModel=<class 'wind.windmodels.HollandWindSpeed'>)

Bases: wind.windmodels.WindProfileModel

McConochie et al’s double Holland vortex model (based on Cardone et al, 1994). This application is the Coral Sea adaptation of the double vortex model (it can also be used for concentric eye-wall configurations).

Parameters

  • lat (float) – Latitude of TC centre.

  • lon (float) – Longitude of TC centre.

  • eP (float) – environmental pressure (hPa).

  • cP (float) – centrral pressure of the TC (hPa).

  • rMax (float) – Radius to maximum wind (km).

  • beta1 (float) – β parameter for the primary vortex.

  • beta2 (float) – β parameter for the secondary vortex.

  • rmax2 (float) – Optional. Radius to the secondary wind maximum (default=250 km).

  • windSpeedModel (windmodels.WindSpeedModel instance.) – A maximum wind speed model to apply.

secondDerivative()

Second derivative of the profile.

velocity(R)

Calculate velocity as a function of radial distance. Represents the velocity of teh gradient level vortex.

Parameters

R – numpy.ndarray of distance of grid from the TC centre.

Returns

Array of gradient level wind speed.

Return type

numpy.ndarray

vorticity(R)

Calculate the vorticity associated with the (gradient level) vortex.

Parameters

R – numpy.ndarray of distance of grid from the TC centre.

Returns

Array of gradient level (relative) vorticity.

Return type

numpy.ndarray

class HollandWindProfile(lat, lon, eP, cP, rMax, beta, windSpeedModel=<class 'wind.windmodels.HollandWindSpeed'>)

Bases: wind.windmodels.WindProfileModel

Holland profile. For r < rMax, we reset the wind field to a cubic profile to avoid the barotropic instability mentioned in Kepert & Wang (2001).

Parameters

  • lat (float) – Latitude of TC centre.

  • lon (float) – Longitude of TC centre.

  • eP (float) – environmental pressure (hPa).

  • cP (float) – centrral pressure of the TC (hPa).

  • rMax (float) – Radius to maximum wind (m).

  • beta (float) – β parameter.

  • windSpeedModel (windmodels.WindSpeedModel instance.) – A maximum wind speed model to apply.

firstDerivative()

First derivative of profile at rMax

secondDerivative()

Second derivative of profile at rMax.

velocity(R)

Calculate velocity as a function of radial distance. Represents the velocity of teh gradient level vortex.

Parameters

R – numpy.ndarray of distance of grid from the TC centre (metres).

Returns

Array of gradient level wind speed.

Return type

numpy.ndarray

vorticity(R)

Calculate the vorticity associated with the (gradient level) vortex.

Parameters

R – numpy.ndarray of distance of grid from the TC centre (metres).

Returns

Array of gradient level (relative) vorticity.

Return type

numpy.ndarray

class HollandWindSpeed(windProfileModel)

Bases: wind.windmodels.WindSpeedModel

Holland (1980), An Analytic Model of the Wind and Pressure Profiles in Hurricanes. Mon. Wea. Rev, 108, 1212-1218 Density of air is assumed to be 1.15 kg/m^3. β is assumed to be 1.3. Other values can be specified. Gradient level wind (assumed maximum).

maximum()

Maximum wind speed.

class HubbertWindField(windProfileModel)

Bases: wind.windmodels.WindFieldModel

Hubbert, G.D., G.J. Holland, L.M. Leslie and M.J. Manton, 1991: A Real-Time System for Forecasting Tropical Cyclone Storm Surges. Weather and Forecasting, 6, 86-97

Parameters

  • R (numpy.ndarray) – Distance from the storm centre to the grid (km).

  • lam (numpy.ndarray) – Direction (geographic bearing, positive clockwise) from storm centre to the grid.

  • vFm (float) – Foward speed of the storm (m/s).

  • thetaFm (float) – Forward direction of the storm (geographic bearing, positive clockwise, radians).

  • thetaMax (float) – Bearing of the location of the maximum wind speed, relative to the direction of motion.

field(R, lam, vFm, thetaFm, thetaMax=0.0)

The wind field.

class JelesnianskiWindProfile(lat, lon, eP, cP, rMax, windSpeedModel=<class 'wind.windmodels.WilloughbyWindSpeed'>)

Bases: wind.windmodels.WindProfileModel

Jelesnianski model of the wind profile.

Parameters

  • lat (float) – Latitude of TC centre.

  • lon (float) – Longitude of TC centre.

  • eP (float) – environmental pressure (hPa).

  • cP (float) – centrral pressure of the TC (hPa).

  • rMax (float) – Radius to maximum wind (m).

  • windSpeedModel (windmodels.WindSpeedModel instance.) – A maximum wind speed model to apply.

velocity(R)

Calculate velocity as a function of radial distance. Represents the velocity of teh gradient level vortex.

Parameters

R – numpy.ndarray of distance of grid from the TC centre (metres).

Returns

Array of gradient level wind speed.

Return type

numpy.ndarray

vorticity(R)

Calculate the vorticity associated with the (gradient level) vortex.

Parameters

R – numpy.ndarray of distance of grid from the TC centre (metres).

Returns

Array of gradient level (relative) vorticity.

Return type

numpy.ndarray

class KepertWindField(windProfileModel)

Bases: wind.windmodels.WindFieldModel

Kepert, J., 2001: The Dynamics of Boundary Layer Jets within the Tropical Cyclone Core. Part I: Linear Theory. J. Atmos. Sci., 58, 2469-2484

field(R, lam, vFm, thetaFm, thetaMax=0.0)
Parameters

  • R (numpy.ndarray) – Distance from the storm centre to the grid (km).

  • lam (numpy.ndarray) – Direction (geographic bearing, positive clockwise) from storm centre to the grid.

  • vFm (float) – Foward speed of the storm (m/s).

  • thetaFm (float) – Forward direction of the storm (geographic bearing, positive clockwise, radians).

  • thetaMax (float) – Bearing of the location of the maximum wind speed, relative to the direction of motion.

class McConochieWindField(windProfileModel)

Bases: wind.windmodels.WindFieldModel

McConochie, J.D., T.A. Hardy and L.B. Mason, 2004: Modelling tropical cyclone over-water wind and pressure fields. Ocean Engineering, 31, 1757-1782.

It appears this paper used 10-minute mean wind speeds for calibration. Therefore, we convert to return a 1-minute sustained wind speed equivalent.

field(R, lam, vFm, thetaFm, thetaMax=0.0)
Parameters

  • R (numpy.ndarray) – Distance from the storm centre to the grid (km).

  • lam (numpy.ndarray) – Direction (geographic bearing, positive clockwise) from storm centre to the grid.

  • vFm (float) – Foward speed of the storm (m/s).

  • thetaFm (float) – Forward direction of the storm (geographic bearing, positive clockwise, radians).

  • thetaMax (float) – Bearing of the location of the maximum wind speed, relative to the direction of motion.

class NewHollandWindProfile(lat, lon, eP, cP, rMax, rGale=150.0)

Bases: wind.windmodels.WindProfileModel

Holland et al. 2010. In this version, the exponent is allowed to vary linearly outside the radius of maximum wind. i.e. rather than take the sqare root, the exponent varies around 0.5. Currently this version does not have a corresponding vorticity profile set up in windVorticity, so it cannot be applied in wind field modelling.

Parameters

  • lat (float) – Latitude of TC centre.

  • lon (float) – Longitude of TC centre.

  • eP (float) – environmental pressure (hPa).

  • cP (float) – centrral pressure of the TC (hPa).

  • rMax (float) – Radius to maximum wind (km).

  • rGale (float) – Radius of gale force winds (default=150 km).

velocity(R)

In this incarnation, we are assuming the pressure rate of change and forward velocity is zero, so there is no requirement for a first-pass guess at x.

Calculate velocity as a function of radial distance. Represents the velocity of teh gradient level vortex.

Parameters

R – numpy.ndarray of distance of grid from the TC centre.

Returns

Array of gradient level wind speed.

Return type

numpy.ndarray

vorticity(R)

Calculate the vorticity associated with the (gradient level) vortex.

Parameters

R – numpy.ndarray of distance of grid from the TC centre.

Returns

Array of gradient level (relative) vorticity.

Return type

numpy.ndarray

class PowellWindProfile(lat, lon, eP, cP, rMax)

Bases: wind.windmodels.HollandWindProfile

Powell et al, 2005. Another definition of the beta parameter inserted into the Holland model. Unlike Willoughby and Rahn’s model, there is no reliance on vMax. Powell et al. also included a small random term, but since the beta value is also used in the vorticity calculation, we need to ensure the values used in this function and the corresponding vorticity function match.

Parameters

  • lat (float) – Latitude of TC centre.

  • lon (float) – Longitude of TC centre.

  • eP (float) – environmental pressure (hPa).

  • cP (float) – centrral pressure of the TC (hPa).

  • rMax (float) – Radius to maximum wind (km).

  • windSpeedModel (windmodels.WindSpeedModel instance.) – A maximum wind speed model to apply.

class RankineWindProfile(lat, lon, eP, cP, rMax, windSpeedModel=<class 'wind.windmodels.WilloughbyWindSpeed'>)

Bases: wind.windmodels.WindProfileModel

Rankine vortex profile. Vmax determined by dp using, by default, the Willoughby & Rahn method.

Parameters

  • lat (float) – Latitude of TC centre.

  • lon (float) – Longitude of TC centre.

  • eP (float) – environmental pressure (hPa).

  • cP (float) – centrral pressure of the TC (hPa).

  • rMax (float) – Radius to maximum wind (km).

  • windSpeedModel (windmodels.WindSpeedModel instance.) – A maximum wind speed model to apply.

velocity(R)

Calculate velocity as a function of radial distance. Represents the velocity of teh gradient level vortex.

This includes an assumption about the shape of the profile outside Rmax. The literature indicates 0.4 < alpha < 0.6 (e.g. see Holland, 1980).

Parameters

R – numpy.ndarray of distance of grid from the TC centre.

Returns

Array of gradient level wind speed.

Return type

numpy.ndarray

vorticity(R)

Calculate the vorticity associated with the (gradient level) vortex.

Parameters

R – numpy.ndarray of distance of grid from the TC centre.

Returns

Array of gradient level (relative) vorticity.

Return type

numpy.ndarray

class SchloemerWindProfile(lat, lon, eP, cP, rMax)

Bases: wind.windmodels.HollandWindProfile

Schloemer’s (1954) is the same as the Holland relation with β = 1

Parameters

  • lat (float) – Latitude of TC centre.

  • lon (float) – Longitude of TC centre.

  • eP (float) – environmental pressure (hPa).

  • cP (float) – centrral pressure of the TC (hPa).

  • rMax (float) – Radius to maximum wind (km).

  • windSpeedModel (windmodels.WindSpeedModel instance.) – A maximum wind speed model to apply.

class WilloughbyWindProfile(lat, lon, eP, cP, rMax, windSpeedModel=<class 'wind.windmodels.WilloughbyWindSpeed'>)

Bases: wind.windmodels.HollandWindProfile

The Willoughby & Rahn (2004) relation, which makes β a function of Vmax, rMax and latitude. We use Willoughby & Rahn’s (2004) relation for Vmax only. This determines the β parameter then calls Holland (which means the profile is cubic within Rmax) to calculate the wind profile. The β term calculation is based on Atlantic and Eastern Pacific cyclone data, not Australian data.

Parameters

  • lat (float) – Latitude of TC centre.

  • lon (float) – Longitude of TC centre.

  • eP (float) – environmental pressure (hPa).

  • cP (float) – centrral pressure of the TC (hPa).

  • rMax (float) – Radius to maximum wind (km).

  • windSpeedModel (windmodels.WindSpeedModel instance.) – A maximum wind speed model to apply.

class WilloughbyWindSpeed(windProfileModel)

Bases: wind.windmodels.WindSpeedModel

Willoughby & Rahn (2004), Parametric Representation of the Primary Hurricane Vortex. Part I: Observations and Evaluation of the Holland (1980) Model. Mon. Wea. Rev., 132, 3033-3048

maximum()

Maximum wind speed.

class WindFieldModel(windProfileModel)

Bases: object

Wind field (boundary layer) models. These define the boundary layer models implemented, which relate the gradient level vortex to the surface wind speed, incorporating the wavenumber-1 assymetry due to storm forward motion, and the effects of (uniform) surface roughness.

Parameters

windProfileModel – A wind.WindProfileModel instance.

property f

Helper property to return the coriolis force from the wind profile.

field(R, lam, vFm, thetaFm, thetaMax=0.0)

The wind field.

property rMax

Helper property to return the maximum radius from the wind profile.

velocity(R)

Helper property to return the wind velocity at radiuses R from the wind profile or the precalculated attribute.

vorticity(R)

Helper property to return the wind vorticity at radiuses R from the wind profile or the precalculated attribute.

class WindProfileModel(lat, lon, eP, cP, rMax, windSpeedModel)

Bases: object

The base wind profile model.

Parameters

  • lat (float) – Latitude of TC centre.

  • lon (float) – Longitude of TC centre.

  • eP (float) – environmental pressure (hPa).

  • cP (float) – centrral pressure of the TC (hPa).

  • rMax (float) – Radius to maximum wind (km).

  • windSpeedModel (windmodels.WindSpeedModel instance.) – A maximum wind speed model to apply.

property dP

Pressure difference.

property vMax

Maximum wind speed.

velocity(R)

Calculate velocity as a function of radial distance R. Represents the velocity of teh gradient level vortex.

Parameters

R – numpy.ndarray of distance of grid from the TC centre.

Returns

Array of gradient level wind speed.

Return type

numpy.ndarray

vorticity(R)

Calculate the vorticity associated with the (gradient level) vortex at radius R.

Parameters

R – numpy.ndarray of distance of grid from the TC centre.

Returns

Array of gradient level (relative) vorticity.

Return type

numpy.ndarray

class WindSpeedModel(windProfileModel)

Bases: object

Abstract wind speed model.

property cP

Current pressure.

property dP

Pressure difference.

property eP

Environment pressure.

maximum()

Maximum wind speed.

allSubclasses(cls)

Recursively find all subclasses of a given class.

field(name)

Helper function to return the appropriate wind field model given a name.

fieldParams(name)

List of additional parameters required for a wind field model.

profile(name)

Helper function to return the appropriate wind profile model given a name.

profileParams(name)

List of additional parameters required for a wind profile model.

Module contents

wind – Wind field calculation

This module contains the core object for the wind field calculations. It provides the radial profile models to define the primary vortex of the simulated TC, and bounday layer models that define the asymmetry induced by surface friction and forward motion of the TC over the earth’s surface. The final output from the module is a netCDF file containing the maximum surface gust wind speed (a 10-minute mean wind speed, at 10 metres above ground level), along with the components (eastward and westward) that generated the wind gust and the minimum mean sea level pressure over the lifetime of the event. If multiple TCs are contained in a track file, then the output file contains the values from all events (for example, an annual maximum wind speed).

Wind field calculations can be run in parallel using MPI if the mpi4py library is found and TCRM is run using the mpirun command. For example, to run with 10 processors:

$ mpirun -n 10 python tcrm.py cairns.ini

wind can be correctly initialised and started by calling the run() with the location of a configFile:

>>> import wind
>>> wind.run('cairns.ini')
class WindfieldAroundTrack(track, profileType='powell', windFieldType='kepert', beta=1.3, beta1=1.5, beta2=1.4, thetaMax=70.0, margin=2.0, resolution=0.05, gustFactor=1.35, gridLimit=None, domain='bounded')

Bases: object

The windfield around the tropical cyclone track.

Parameters

  • track (Track) – the tropical cyclone track.

  • profileType (str) – the wind profile type.

  • windFieldType (str) – the wind field type.

  • beta (float) – wind field parameter.

  • beta1 (float) – wind field parameter.

  • beta2 (float) – wind field parameter.

  • thetaMax (float) –

  • margin (float) –

  • resolution (float) – Grid resolution (in degrees)

  • gustFactor (float) – Conversion from 1-min mean to 0.2-sec gust wind speed, for off-sea conditions. See WMO TD1555 (2010) for details.

  • gridLimit (dict) – the domain where the tracks will be generated. The dict should contain the keys xMin, xMax, yMin and yMax. The y variable bounds the latitude and the x variable bounds the longitude.

localWindField(i)

Calculate the local wind field at time i around the tropical cyclone.

Parameters

i (int) – the time.

polarGridAroundEye(i)

Generate a polar coordinate grid around the eye of the tropical cyclone at time i.

Parameters

i (int) – the time.

pressureProfile(i, R)

Calculate the pressure profile at time i at the radiuses R around the tropical cyclone.

Parameters

  • i (int) – the time.

  • R (numpy.ndarray) – the radiuses around the tropical cyclone.

regionalExtremes(gridLimit, timeStepCallback=None)

Calculate the maximum potential wind gust and minimum pressure over the region throughout the life of the tropical cyclone.

Parameters

  • gridLimit (dict) – the domain where the tracks will be considered. The dict should contain the keys xMin, xMax, yMin and yMax. The y variable bounds the latitude and the x variable bounds the longitude.

  • timeStepCallback (function) – the function to be called on each time step.

class WindfieldGenerator(config, margin=2.0, resolution=0.05, profileType='powell', windFieldType='kepert', beta=1.5, beta1=1.5, beta2=1.4, thetaMax=70.0, gridLimit=None, domain='bounded', multipliers=None, windfieldPath=None)

Bases: object

The wind field generator.

Parameters

  • margin (float) –

  • resolution (float) –

  • profileType (str) – the wind profile type.

  • windFieldType (str) – the wind field type.

  • beta (float) – wind field parameter.

  • beta1 (float) – wind field parameter.

  • beta2 (float) – wind field parameter.

  • thetaMax (float) –

  • gridLimit (dict) – the domain where the tracks will be generated. The dict should contain the keys xMin, xMax, yMin and yMax. The y variable bounds the latitude and the x variable bounds the longitude.

calcLocalWindfield(results)

Calculate a local wind field using the regional windfield data

Parameters

results – collection of :tuple: track and wind field data

calculateExtremesFromTrack(track, callback=None)

Calculate the wind extremes given a single tropical cyclone track.

Parameters

  • track (Track) – the tropical cyclone track.

  • callback (function) – optional function to be called at each timestep to extract point values for specified locations.

calculateExtremesFromTrackfile(trackfile, callback=None)

Calculate the wind extremes from a trackfile that might contain a number of tropical cyclone tracks. The wind extremes are calculated over the tracks, i.e., the maximum gusts and minimum pressures over all tracks are retained.

Parameters

  • trackfile (str) – the file name of the trackfile.

  • callback (function) – optional function to be called at each timestep to extract point values for specified locations.

dumpGustsFromTrackfiles(trackfiles, windfieldPath, timeStepCallback=None)

Helper method to dump the maximum wind speeds (gusts) observed over a region to netcdf files. One file is created for every track file.

Parameters

  • trackfiles (list of str) – a list of track file filenames.

  • windfieldPath (str) – the path where to store the gust output files.

  • filenameFormat (str) – the format string for the output file names. The default is set to ‘gust-%02i-%04i.nc’.

  • progressCallback (function) – optional function to be called after a file is saved. This can be used to track progress.

  • timeStepCallback – optional function to be called at each timestep to extract point values for specified locations.

dumpGustsFromTracks(trackiter, windfieldPath, timeStepCallback=None)

Dump the maximum wind speeds (gusts) observed over a region to netcdf files. One file is created for every track file.

Parameters

  • trackiter (list of Track objects) – a list of Track objects.

  • windfieldPath (str) – the path where to store the gust output files.

  • filenameFormat (str) – the format string for the output file names. The default is set to ‘gust-%02i-%04i.nc’.

  • timeStepCallback – optional function to be called at each timestep to extract point values for specified locations.

plotGustToFile(result, filename)

Plot the wind field on a map

saveGustToFile(trackfile, result, filename)

Save gusts to a file.

setGridLimit(track)

Set the outer bounds of the grid to encapsulate the extent of a single TC track.

Parameters

track – Track object.

balanced(iterable)

Balance an iterator across processors.

This partitions the work evenly across processors. However, it requires the iterator to have been generated on all processors before hand. This is only some magical slicing of the iterator, i.e., a poor man version of scattering.

filterTracks(tracks, gridLimit, margin)
inRegion(t, gridLimit, margin)
Parameters

t – Track object

Returns

True if the track enters the simulation grid, False otherwise

loadTracks(trackfile)

Read tracks from a track .nc file and return a list of Track objects.

This calls the function ncReadTrackData to parse the track .nc file.

Parameters

trackfile (str) – the track data filename.

Returns

list of Track objects.

loadTracksFromFiles(trackfiles, gridLimit, margin)

Generator that yields Track objects from a list of track filenames.

When run in parallel, the list trackfiles is distributed across the MPI processors using the balanced function. Track files are loaded in a lazy fashion to reduce memory consumption. The generator returns individual tracks (recall: a trackfile can contain multiple tracks) and only moves on to the next file once all the tracks from the current file have been returned.

Parameters

trackfiles (list of strings) – list of track filenames. The filenames must include the path to the file.

loadTracksFromPath(path)

Helper function to obtain a generator that yields Track objects from a directory containing track .csv files.

This function calls loadTracksFromFiles to obtain the generator and track filenames are processed in alphabetical order.

Parameters

path (str) – the directory path.

run(configFile, callback=None)

Run the wind field calculations.

Parameters

  • configFile (str) – path to a configuration file.

  • callback (func) – optional callback function to track progress.