Geometries in ScotchPy

Geometries are implemented in ScotchPy with the Geom class.

The Geom class

class Geom

The Geom constructor itself calls libscotch’s geomAlloc function. This object doesn’t need to be initialized.


init()

This routine initializes the fields of the Geom object instance. Called by a class constructor when init=True (by default). Mandatory before calling geom routines or after calling exit() in order to re-use the same Geom instance.


exit()

This routine cleans-up all fields of the instance. Is the opposite of the init() routine. Called automatically when the object is destroyed. Calling explicitly this method is only required when an init() call follows.


free()

This routine frees the geometry data. Can be called after the geometry is no longer needed. Calls exit() and init() to reinitialize the object.


data(as_dict=False)

This routine returns the data of the geometry. :param as_dict: If True, the requested data is returned as a dict. If not, it is returned as a 2-element tuple. :type as_dict: Boolean :returns: Values in this order: dimnnbr, geomtab. :rtype: Tuple or Dict


The following routines, which need to be called from a :class:`Graph` (or a :class:`Mesh` if specified) object are relayed to the Geom class but not present in the class itself:


geom_load_chac(geom, grafstream, geomstream, string)

This routine loads the geometry of the graph from the given file or stream in the Chaco graph format.

Parameters:

  • geom (Geom) – The geometry to be loaded.

  • grafstream (Either a file object (result of an open(), don’t forget to close it) or a filename, as a string or as a bytes object (such as b"file/name")) – Input file or stream to read from.

  • geomstream (Either a file object (result of an open(), don’t forget to close it) or a filename, as a string or as a bytes object (such as b"file/name")) – Input file or stream to read from.

  • string (String) – The string to be used.


geom_load_habo(geom, grafstream/meshstream, geomstream, string)

This routine loads the geometry of the graph or the mesh from the given file or stream in the Harwell-Boeing square assembled matrix format.

Parameters:

  • geom (Geom) – The geometry to be loaded.

  • grafstream (Either a file object (result of an open(), don’t forget to close it) or a filename, as a string or as a bytes object (such as b"file/name")) – Input file or stream to read from.

  • geomstream (Either a file object (result of an open(), don’t forget to close it) or a filename, as a string or as a bytes object (such as b"file/name")) – Input file or stream to read from.

  • string (String) – The string to be used.


geom_load_scot(geom, grafstream/meshstream, geomstream, string)

This routine loads the geometry of the graph or the mesh from the given file or stream in the Scotch graph/mesh and geometry formats.

Parameters:

  • geom (Geom) – The geometry to be loaded.

  • grafstream (Either a file object (result of an open(), don’t forget to close it) or a filename, as a string or as a bytes object (such as b"file/name")) – Input file or stream to read from.

  • geomstream (Either a file object (result of an open(), don’t forget to close it) or a filename, as a string or as a bytes object (such as b"file/name")) – Input file or stream to read from.

  • string (String) – The string to be used.


geom_save_chac(geom, grafstream, geomstream, string)

This routine saves the geometry of the graph to the given file or stream in the Chaco graph format.

Parameters:

  • geom (Geom) – The geometry to be saved.

  • grafstream (Either a file object (result of an open(), don’t forget to close it) or a filename, as a string or as a bytes object (such as b"file/name")) – Input file or stream to write to.

  • geomstream (Either a file object (result of an open(), don’t forget to close it) or a filename, as a string or as a bytes object (such as b"file/name")) – Input file or stream to write to.

  • string (String) – The string to be used.


geom_save_scot(geom, grafstream/meshstream, geomstream, string)

This routine saves the geometry of the graph or the mesh to the given file or stream in the Scotch graph/mesh and geometry formats.

Parameters:

  • geom (Geom) – The geometry to be saved.

  • grafstream (Either a file object (result of an open(), don’t forget to close it) or a filename, as a string or as a bytes object (such as b"file/name")) – Input file or stream to write to.

  • geomstream (Either a file object (result of an open(), don’t forget to close it) or a filename, as a string or as a bytes object (such as b"file/name")) – Input file or stream to write to.

  • string (String) – The string to be used.


geom_alloc()

This routine allocates a new geometry object and returns it. :returns: The new geometry object. :rtype: Geom