pyissm.model.classes.flowequation

class pyissm.model.classes.flowequation(other=None)

Bases: manage_state

Flow equation class for ISSM.

This class contains parameters for configuring flow equations in the ISSM framework. It allows users to select and configure different ice flow approximations such as SIA, SSA, Higher-Order, and Full-Stokes, along with their associated numerical methods and boundary conditions.

Parameters:: other (any, optional) – Any other class object that contains common fields to inherit from. If values in other differ from default values, they will override the default values.

isSIA

Is the Shallow Ice Approximation (SIA) used?

Type:: int, default=0

isL1L2

Are L1L2 equations used?

Type:: int, default=0

isSSA

Is the Shelfy-Stream Approximation (SSA) used?

Type:: int, default=0

isMOLHO

Are MOno-layer Higher-Order (MOLHO) equations used?

Type:: int, default=0

isHO

Is the Higher-Order (HO) approximation used?

Type:: int, default=0

isFS

Are the Full-Stokes (FS) equations used?

Type:: int, default=0

isNitscheBC

Is weakly imposed condition used?

Type:: int, default=0

FSNitscheGamma

Gamma value for the Nitsche term.

Type:: float, default=1e6

fe_SSA

Finite Element for SSA: ‘P1’, ‘P1bubble’, ‘P1bubblecondensed’, ‘P2’.

Type:: str, default=’P1’

fe_HO

Finite Element for HO: ‘P1’, ‘P1bubble’, ‘P1bubblecondensed’, ‘P2’.

Type:: str, default=’P1’

fe_FS

Finite Element for FS: ‘MINI’, ‘MINIcondensed’, ‘TaylorHood’, ‘XTaylorHood’, ‘OneLayerP4z’, ‘CrouzeixRaviart’.

Type:: str, default=’MINIcondensed’

augmented_lagrangian_r

Augmented Lagrangian parameter r.

Type:: float, default=1

augmented_lagrangian_rhop

Augmented Lagrangian parameter rhop.

Type:: float, default=1

augmented_lagrangian_rlambda

Augmented Lagrangian parameter rlambda.

Type:: float, default=1

augmented_lagrangian_rholambda

Augmented Lagrangian parameter rholambda.

Type:: float, default=1

XTH_theta

XTH theta parameter.

Type:: float, default=0

vertex_equation

Vertex equation parameter.

Type:: float, default=np.nan

element_equation

Element equation parameter.

Type:: float, default=np.nan

borderSSA

Border parameter for SSA.

Type:: float, default=np.nan

borderHO

Border parameter for HO.

Type:: float, default=np.nan

borderFS

Border parameter for FS.

Type:: float, default=np.nan

Examples

>>> md.flowequation = pyissm.model.classes.flowequation()
>>> md.flowequation.isSSA = 1
>>> md.flowequation.fe_SSA = 'P1bubble'
>>> md.flowequation.FSNitscheGamma = 1e5

__init__(other=None)

Initialize the instance with optional field inheritance.

Parameters:: other (object, optional) – Another instance to inherit field values from. If provided, any fields in the current instance that differ from the default values and exist in ‘other’ will be replaced with the values from ‘other’.

Notes

The inheritance process:

Iterates through all attributes of the current instance

Checks if the same attribute exists in the ‘other’ instance

Compares field values using _fields_equal()

If different, replaces the current value with the ‘other’ value

This enables the common ISSM pattern where classes can inherit configurations from existing instances while maintaining their default values for unspecified fields.

Methods

`__init__`([other])	Initialize the instance with optional field inheritance.
`check_consistency`(md, solution, analyses)	Check consistency of the [flowequation.default] parameters.
`issm_enum_string`()	Default ISSM C++ enum string used during marshalling.
`marshall_class`(fid, prefix[, md])	Marshall [flowequation.default] parameters to a binary file.

check_consistency(md, solution, analyses)

Check consistency of the [flowequation.default] parameters.

Parameters:

md (pyissm.model.Model) – The model object to check.
solution (str) – The solution name to check.
analyses (list of str) – List of analyses to check consistency for.

Returns:

md – The model object with any consistency errors noted.

Return type:

pyissm.model.Model

marshall_class(fid, prefix, md=None)

Marshall [flowequation.default] parameters to a binary file.

Parameters:

fid (file object) – The file object to write the binary data to.
prefix (str) – Prefix string used for data identification in the binary file.
md (pyissm.model.Model, optional) – ISSM model object needed in some cases.

Return type:

None