flopy.mfusg.mfusggnc module

Mfusggnc module.

This is for the Ghost Node Correction (GNC) Package for MODFLOW-USG. Contains the MfUsgGnc class. Note that the user can access the MfUsgGnc class as flopy.mfusg.MfUsgGnc.

class MfUsgGnc(model, numgnc=0, numalphaj=1, i2kn=0, isymgncn=0, iflalphan=0, gncdata=None, extension='gnc', options=None, unitnumber=None, filenames=None)

Bases: Package

MODFLOW USG Ghost Node Correction (GNC) Package Class.

Parameters:

• numgnc (integer) – numgnc (integer) is the number of GNC entries.

• numalphaj (integer) – numalphaj (integer) is the number of contributing factors.

• i2kn (integer) – 0 : second-order correction not applied to unconfined transmissivity. 1 : second-order correction applied to unconfined transmissivity.

• isymgncn (integer) – 0 : implicit update on left-hand side matrix for asymmetric systems. 1 : explicit update on right-hand side vector for symmetric systems.

• iflalphan (integer) –

  0 : AlphaJ is contributing factors from all adjacent contributing nodes. 1 : AlphaJ represent the saturated conductances between the ghost node

  location and node j, and the contributing factors are computed internally using the equations for the unconfined conductances.

• gncdata ([cellidn, cellidm, cellidsj, alphasj]) –

  • cellidn ((integer, …)) is the cellid of the cell in which the ghost node is located.

  • cellidm ((integer, …)) is the cellid of the connecting cell

  • cellidsj ((integer, …)) is the array of CELLIDS for the contributing j cells. This Item is repeated for each of the numalphaj adjacent contributing cells of the ghost node.

  • alphasj (double) is the contributing factors for each contributing node in CELLIDSJ. This Item is repeated for each of the numalphaj adjacent contributing cells of the ghost node.

• model (model object) – The model object (of type flopy.modflow.mf.Modflow) to which this package will be added.

• extension (str, optional) – File extension (default is ‘gnc’.

• unitnumber (int, optional) – FORTRAN unit number for this package (default is None).

• filenames (str or list of str) – Filenames to use for the package. If filenames=None the package name will be created using the model name and package extension. If a single string is passed the package will be set to the string. Default is None.

Notes

Examples

>>> import flopy
>>> m = flopy.modflow.Modflow()
>>> gnc = flopy.mfusg.MfUsgGnc(m)

static get_default_dtype(numalphaj, iflalphan)

Returns default GNC dtypes.

static get_empty(numgnc=0, numalphaj=1, iflalphan=0)

Returns empty GNC recarray of default dtype.

classmethod load(f, model, pak_type='gnc', ext_unit_dict=None, **kwargs)

Load an existing package.

Parameters:

• f (filename or file handle) – File to load.

• model (model object) – The model object (of type flopy.modflow.mf.Modflow) to which this package will be added.

• ext_unit_dict (dictionary, optional) – If the arrays in the file are specified using EXTERNAL, or older style array control records, then f should be a file handle. In this case ext_unit_dict is required, which can be constructed using the function flopy.utils.mfreadnam.parsenamefile.

Returns:

gnc

Return type:

MfUsgGnc object

Examples

>>> import flopy
>>> m = flopy.modflow.Modflow()
>>> gnc = flopy.modflow.ModflowGnc.load('test.gnc', m)

write_file(f=None, check=False)

Write the package file.

Parameters:

f (filename or file handle) – File to write to.

Return type:

None