bdf/utils Package¶

This is the pyNastran.bdf.rst file.

`utils` Module¶

Defines various utilities including:

parse_patran_syntax
parse_patran_syntax_dict
Position
PositionWRT
TransformLoadWRT

pyNastran.bdf.utils.Position(xyz, cid, model, is_cid_int=None)[source]¶

Gets the point in the global XYZ coordinate system.

Parameters:	xyz : (3,) ndarray the position of the GRID in an arbitrary coordinate system cid : int the coordinate ID for xyz model : BDF() the BDF model object is_cid_int : bool is cid/cid_new an integer or a Coord object (deprecated)
Returns:	xyz2 : (3,) ndarray the position of the GRID in an arbitrary coordinate system

pyNastran.bdf.utils.PositionWRT(xyz, cid, cid_new, model, is_cid_int=None)[source]¶

Gets the location of the GRID which started in some arbitrary system and returns it in the desired coordinate system

Parameters:	xyz : (3, ) float ndarray the position of the GRID in an arbitrary coordinate system cid : int the coordinate ID for xyz cid_new : int the desired coordinate ID model : BDF() the BDF model object is_cid_int : bool is cid/cid_new an integer or a Coord object (deprecated)
Returns:	xyz_local : (3, ) float ndarray the position of the GRID in an arbitrary coordinate system

pyNastran.bdf.utils.TransformLoadWRT(F, M, cid, cid_new, model, is_cid_int=None)[source]¶

Transforms a force/moment from an arbitrary coordinate system to another coordinate system.

Parameters:	Fxyz : (3, ) float ndarray the force in an arbitrary coordinate system Mxyz : (3, ) float ndarray the moment in an arbitrary coordinate system cid : int the coordinate ID for xyz cid_new : int the desired coordinate ID model : BDF() the BDF model object is_cid_int : bool is cid/cid_new an integer or a Coord object (deprecated)
Returns:	Fxyz_local : (3, ) float ndarray the force in an arbitrary coordinate system Mxyz_local : (3, ) float ndarray the force in an arbitrary coordinate system

pyNastran.bdf.utils.parse_patran_syntax(node_sets, pound=None)[source]¶

Parses Patran’s syntax for compressing nodes/elements

Parameters:

node_sets : str: the node_set to parse
pound : int / str: value : the pound value (e.g. # in 1:#, which means all)

Returns:

nodes : List[int]

the integer values

Patran has a short syntax of the form:

String	Output
“1 2 3”	[1, 2, 3]
“5:10”	[5, 6, 7, 8, 9, 10]
“12:20:2”	[12, 14, 16, 18, 20]

Examples

Example 1

>>> node_sets = "1 2 3 5:10 12:20:2"
>>> data = parse_patran_syntax(node_sets)
>>> data
data = [1, 2, 3, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20]

Example 2

>>> node_sets = "1 2 3:#"
>>> data = parse_patran_syntax(node_sets, pound=10)
>>> data
data = [1, 2, 3, 5, 6, 7, 8, 9, 10]

Warning

Don’t include the n/node or e/element or any other identifier, just a string of “1 2 3 5:10 12:20:2”. Use parse_patran_syntax_dict to consider the identifier.

pyNastran.bdf.utils.parse_patran_syntax_dict(node_sets, pound_dict=None, msg='')[source]¶

Parses Patran’s syntax for compressing nodes/elements

Parameters:	node_sets : str the node_set to parse pound_dict : List[str] key : the string value : the pound value (e.g. 1:#) msg : str error message; currently unused
Returns:	nodes : Dict[str] = List[int] str : the key values : the integer values for that key

Notes

An identifier (e.g. “e”) must be used. Use parse_patran_syntax to skip the identifier.

Warning

case sensitive

Examples

Example 1

>>> node_sets = "e 1:3 n 2:6:2 Node 10:13"
>>> data = parse_patran_syntax_dict(node_sets)
>>> data = {
      'e'    : [1, 2, 3],
      'n'    : [2, 4, 6],
      'Node' : [10, 11, 12, 13],
}

Example 2

>>> node_sets = "e 1:3 n 2:6:2 Node 10:#"

# a pound character will be set to 20, but only for ‘Node’, but not # ‘n’ so define it twice if needed >>> pounds = {‘Node’ : 20} >>> data = parse_patran_syntax_dict(node_sets, pounds=pounds) >>> data = {

‘e’ : [1, 2, 3], ‘n’ : [2, 4, 6], ‘Node’ : [10, 11, 12, 13],

}

pyNastran.bdf.utils.parse_patran_syntax_dict_map(node_sets, type_map, msg='')[source]¶

Parses Patran’s syntax for compressing nodes/elements

Parameters:	node_sets : str the node_set to parse type_map : dict[key_in] key_in : str the name of the input string key_out : str the name of the out string #pound_dict : List[str] #key : the string #value : the pound value (e.g. 1:#) msg : str error message; currently unused
Returns:	nodes : Dict[str] = List[int] str : the key values : the integer values for that key

Examples

Example 1 .. code-block:: python

# we drop the coordinate systems because we didn’t request them # (coord is not referenced) # >>> node_sets = “e 1:3 n 2:6:2 Node 10:13 N 15 coord 1:10” >>> type_map = {

‘n’ : ‘Node’, ‘Node’ : ‘Node’, ‘e’ : ‘Element’, ‘Elm’ : ‘Element’, ‘Element’ : ‘Element’,

}

Example 2 >>> data = parse_patran_syntax_dict(node_sets, type_map) >>> data = {

‘Element’ : [1, 2, 3], ‘Node’ : [2, 4, 6, 10, 11, 12, 13, 15],

}

Todo

doesn’t support pound_dict

pyNastran.bdf.utils.split_eids_along_nids(model, eids, nids)[source]¶

Dissassociate a list of elements along a list of nodes.

The expected use of this function is that you have two bodies that are incorrectly equivalenced and you would like to create duplicate nodes at the same location and associate the new nodes with one half of the elements.

Pick the nodes along the line and the elements along one side of the line.

Parameters:	model : BDF() the BDF model eids : list/tuple element ids to disassociate nids : list/tuple node ids to disassociate Implicitly returns model with additional nodes.

Notes

xref should be set to False for this function.

pyNastran.bdf.utils.transform_load(F, M, cid, cid_new, model)[source]¶

Transforms a force/moment from an arbitrary coordinate system to another coordinate system.

Parameters:	Fxyz : (3, ) float ndarray the force in an arbitrary coordinate system Mxyz : (3, ) float ndarray the moment in an arbitrary coordinate system cid : int the coordinate ID for xyz cid_new : int the desired coordinate ID model : BDF() the BDF model object
Returns:	Fxyz_local : (3, ) float ndarray the force in an arbitrary coordinate system Mxyz_local : (3, ) float ndarray the force in an arbitrary coordinate system

pyNastran.bdf.utils.write_patran_syntax_dict(dict_sets)[source]¶

writes partran syntax

Parameters:	dict_sets : Dict[str] = List[int] str : the key values : the integer values for that key
Returns:	node_sets : str the node_set to parse See `parse_patran_syntax_dict` for explanation of usage

`write_path` Module¶

Defines following useful methods:

write_include(filename, is_windows=True)

pyNastran.bdf.write_path._split_path(abspath, is_windows)[source]¶

Takes a path and splits it into the various components.

This is a helper method for write_include

pyNastran.bdf.write_path.write_include(filename, is_windows=None)[source]¶

Writes a bdf INCLUDE file line given an imported filename.

Parameters:

filename : str

the filename to write

is_windows : bool; default=None

True/False : Windows has a special format for writing INCLUDE: files, so the format for a BDF that will run on Linux and Windows is different.

None : Check the platform

For a model that will run on Linux:

..code-block:: python

fname = r’/opt/NASA/test1/test2/test3/ test4/formats/pynastran_v0.6/pyNastran/bdf/model.inc’ write_include(fname, is_windows=False)

We want:

..code-block:: python

INCLUDE /opt/NASA/test1/test2/test3/test4/formats/pynastran_v0.6/: pyNastran/bdf/model.inc

bdf/utils Package¶

utils Module¶

write_path Module¶

`utils` Module¶

`write_path` Module¶