pyissm.model.Model

class pyissm.model.Model

Bases: object

High-level container for all components of an Ice-sheet and Sea-level System Model (ISSM) model. Initializes a collection of model components, each of which may store inputs, settings, and results related to ice sheet simulation.

mesh

Mesh properties.

Type:: classes.mesh.mesh2d

mask

Defines grounded and floating elements.

Type:: classes.mask

geometry

Surface elevation, bedrock topography, ice thickness, etc.

Type:: classes.geometry

constants

Physical constants.

Type:: classes.constants

smb

Surface mass balance.

Type:: classes.smb.default

basalforcings

Bed forcings.

Type:: classes.basalforcings.default

materials

Material properties.

Type:: classes.materials.ice

damage

Damage propagation laws.

Type:: classes.damage

friction

Basal friction / drag properties.

Type:: classes.friction.default

flowequation

Flow equations.

Type:: classes.flowequation

timestepping

Timestepping for transient models.

Type:: classes.timestepping.default

initialization

Initial guess / state.

Type:: classes.initialization

rifts

Rifts properties.

Type:: classes.rifts

solidearth

Solidearth inputs and settings.

Type:: classes.solidearth.earth

dsl

Dynamic sea level.

Type:: classes.dsl.default

debug

Debugging tools (valgrind, gprof).

Type:: classes.debug

verbose

Verbosity level in solve.

Type:: classes.verbose

settings

Settings properties.

Type:: classes.issmsettings

toolkits

Toolkit options for each solution.

Type:: classes.toolkits

cluster

Cluster parameters (number of CPUs, etc.).

Type:: classes.cluster.generic

balancethickness

Parameters for balancethickness solution.

Type:: classes.balancethickness

stressbalance

Parameters for stressbalance solution.

Type:: classes.stressbalance

groundingline

Parameters for groundingline solution.

Type:: classes.groundingline

hydrology

Parameters for hydrology solution.

Type:: classes.hydrology.shreve

masstransport

Parameters for masstransport solution.

Type:: classes.masstransport

thermal

Parameters for thermal solution.

Type:: classes.thermal

steadystate

Parameters for steadystate solution.

Type:: classes.steadystate

transient

Parameters for transient solution.

Type:: classes.transient

levelset

Parameters for moving boundaries (level-set method).

Type:: classes.levelset

calving

Parameters for calving.

Type:: classes.calving.default

frontalforcings

Parameters for frontalforcings.

Type:: classes.frontalforcings.default

love

Parameters for love solution.

Type:: classes.love.default

esa

Parameters for elastic adjustment solution.

Type:: classes.esa

sampling

Parameters for stochastic sampler.

Type:: classes.sampling

autodiff

Automatic differentiation parameters.

Type:: classes.autodiff

inversion

Parameters for inverse methods.

Type:: classes.inversion.default

qmu

Dakota properties.

Type:: classes.qmu.default

amr

Adaptive mesh refinement properties.

Type:: classes.amr

results

Model results.

Type:: classes.results.default

outputdefinition

Output definition.

Type:: classes.outputdefinition

radaroverlay

Radar image for plot overlay.

Type:: classes.radaroverlay

miscellaneous

Miscellaneous fields.

Type:: classes.miscellaneous

stochasticforcing

Stochasticity applied to model forcings.

Type:: classes.stochasticforcing

Examples

>>> md = pyissm.model.Model()
>>> md.mesh
<mesh object>
>>> md.mask
<mask object>
>>> md.geometry
<geometry object>

__init__()

Initialize default sub-classes and parameterizations for the ISSM model object.

This constructor initializes all default model components and their associated classes, setting up the complete structure for an Ice-sheet and Sea-level System Model (ISSM) simulation.

Notes

All attributes are initialized with their default class implementations. See the class docstring for detailed descriptions of each attribute.

Methods

`__init__`()	Initialize default sub-classes and parameterizations for the ISSM model object.
`check_message`(string)	Notify about a model consistency error, update internal state, and return the instance.
`collapse`()	Collapse a 3D mesh into a 2D mesh.
`extract`(area)	Extract a submodel from a larger model based on a domain or flag list.
`extrude`([num_layers, extrusion_exponent, ...])	Vertically extrude a 2D mesh to create a 3D mesh.
`model_class_names`()	Return a sorted list of registered model class attribute names.

check_message(string)

Notify about a model consistency error, update internal state, and return the instance.

This method prints a formatted consistency error message to standard output, marks the instance as inconsistent by setting self.private.isconsistent, and returns the instance to allow for method chaining.

Parameters:: string (str) – Human-readable description of the consistency error. This will be inserted into the printed message: Model consistency error: {string}.
Returns:: The same instance on which the method was called, enabling fluent/chained calls.
Return type:: self

Notes

This method mutates the instance state (self.private.isconsistent) and prints output. It does not raise exceptions.

Examples

>>> obj.check_message("missing parameter")
    Model consistency error: missing parameter
>>> obj.private.isconsistent
    False

collapse()

Collapse a 3D mesh into a 2D mesh.

This method collapses a 3D model into a 2D model by depth-averaging all fields. The original 3D mesh information is preserved, but the model is modified in-place.

The following operations are performed:

Projects 3D friction coefficients to 2D (at bedrock level)

Averages or projects 3D observations and initialization fields to 2D

Collapses boundary conditions from 3D to 2D

Depth-averages velocity and material properties

Projects 3D results and output definitions to 2D

Rebuilds mesh connectivity for the 2D mesh

Returns:

md – The same model instance with updated 2D mesh and collapsed fields. Original 3D mesh information is preserved.

Return type:

pyissm.model.Model

Raises:

Exception –

If the model does not contain a 3D mesh. - If an unsupported friction type is encountered.

Notes

This method modifies the model in-place. All 3D fields are projected or averaged to create 2D equivalents.

Examples

>>> md = pyissm.model.Model()
>>> md.collapse()

See also

pyissm.model.Model.extrude(): Extrude model in vertical direction
pyissm.model.Model.collapse(): Collapse model layers

extrude(num_layers=None, extrusion_exponent=None, lower_exponent=None, upper_exponent=None, coefficients=None)

Vertically extrude a 2D mesh to create a 3D mesh.

Vertically extrude a 2D mesh and create corresponding 3D prism mesh. The vertical distribution can follow a polynomial law, two polynomial laws (one for lower part and one for upper part), or be described by a list of coefficients between 0 and 1.

Parameters:

num_layers (int, optional) – Number of vertical layers to create. Required when using polynomial extrusion (single or dual exponent). Must be at least 2.
extrusion_exponent (float, optional) – Single polynomial exponent for uniform vertical distribution. Must be >= 0. When specified, creates extrusion list using this exponent.
lower_exponent (float, optional) – Polynomial exponent for the lower part of the mesh. Must be >= 0. Used in conjunction with upper_exponent for non-uniform vertical distribution.
upper_exponent (float, optional) – Polynomial exponent for the upper part of the mesh. Must be >= 0. Used in conjunction with lower_exponent for non-uniform vertical distribution.
coefficients (array_like, optional) – List of coefficients between 0 and 1 defining custom vertical distribution. Automatically includes 0 and 1 if not present. Alternative to polynomial extrusion.

Returns:

md – The same model instance with updated 3D mesh and extruded model fields. Original 2D mesh is preserved in mesh.x2d, mesh.y2d, mesh.elements2d, etc.

Return type:

pyissm.model.Model

Raises:

TypeError –

If extrusion_exponent or lower_exponent/upper_exponent <= 0. - If coefficients contain values outside [0, 1] range. - If num_layers < 2. - If mesh is already 3D (extrude called more than once).

Notes

The function performs the following operations:

Creates 3D prism elements from 2D elements

Distributes nodes vertically between bed and surface according to extrusion parameters

Maintains vertex and element numbering relationships via lowervertex,

uppervertex, lowerelements, and upperelements - Projects all 2D model fields to 3D using extrude methods - Updates mesh connectivity and boundary information - Preserves the original 2D mesh information for reference

Examples

Single exponent (uniform-like distribution):

>>> md = md.extrude(num_layers=15, extrusion_exponent=1.3)

Dual exponents (non-uniform distribution):

>>> md = md.extrude(num_layers=15, lower_exponent=1.3, upper_exponent=1.2)

Custom coefficients (specific layer distribution):

>>> md = md.extrude(coefficients=[0, 0.2, 0.5, 0.7, 0.9, 0.95, 1])