`nodes` Module¶

Inheritance diagram of pyNastran.bdf.cards.nodes

All nodes are defined in this file. This includes:

Node * XPoint

EPOINT

SPOINT

XPoints * EPOINTs * SPOINTs

GRID

GRDSET

GRIDB

POINT

Ring * RINGAX

SEQGP

All ungrouped elements are Node objects.

The EPOINT/SPOINT classes refer to a single EPOINT/SPOINT. The EPOINTs/SPOINTs classes are for multiple degrees of freedom (e.g. an SPOINT card).

class pyNastran.bdf.cards.nodes.EPOINT(nid, comment='')[source]¶

Bases: pyNastran.bdf.cards.nodes.XPoint

defines the EPOINT class

Creates the EPOINT card

Parameters

nidint: the EPOINT id
commentstr; default=’’: a comment for the card

type = 'EPOINT'¶

class pyNastran.bdf.cards.nodes.EPOINTs(ids, comment='')[source]¶

Bases: pyNastran.bdf.cards.nodes.XPoints

1	2	3	4	5	6	7	8	9
EPOINT	ID1	THRU	ID2
EPOINT	ID1	ID1	ID3	ID4	ID5	ID6	ID7	ID8
	ID8	etc.

Creates the EPOINTs card that contains many EPOINTs

Parameters

idsList[int]: EPOINT ids
commentstr; default=’’: a comment for the card

create_epointi()[source]¶: Creates individal EPOINT objects

type = 'EPOINT'¶

class pyNastran.bdf.cards.nodes.GRDSET(cp: int, cd: int, ps: str, seid: int, comment: str = '')[source]¶

Bases: pyNastran.bdf.cards.base_card.BaseCard

Defines default options for fields 3, 7, 8, and 9 of all GRID entries.

1	2	3	4	5	6	7	8	9
GRDSET		CP				CD	PS	SEID

Creates the GRDSET card

Parameters

cpint; default=0: the xyz coordinate frame
cdint; default=0: the analysis coordinate frame
psstr; default=’’: Additional SPCs in the analysis coordinate frame (e.g. ‘123’). This corresponds to DOF set SG.
seidint; default=0: superelement id TODO: how is this used by Nastran???
commentstr; default=’’: a comment for the card

Cd()[source]¶

Gets the output coordinate system

Returns

cdint: the output coordinate system

Cp()[source]¶

Gets the analysis coordinate system

Returns

cpint: the analysis coordinate system

Ps()[source]¶

Gets the GRID-based SPC

Returns

psstr: the GRID-based SPC

SEid()[source]¶

Gets the Superelement ID

Returns

seidint: the Superelement ID

classmethod _init_from_empty()[source]¶

classmethod add_card(card, comment='')[source]¶

Adds a GRDSET card from BDF.add_card(...)

Parameters

cardBDFCard(): a BDFCard object
commentstr; default=’’: a comment for the card

cd = None¶: Analysis coordinate system

cp = None¶: Output Coordinate System

cross_reference(model: BDF) → None[source]¶

Cross links the card so referenced cards can be extracted directly

Parameters

modelBDF(): the BDF object

ps = None¶: Default SPC constraint on undefined nodes

raw_fields()[source]¶

Gets the fields in their unmodified form

Returns

fieldsList[varies]: the fields that define the card

repr_fields()[source]¶

Gets the fields in their simplified form

Returns

fieldsList[varies]: the fields that define the card

seid = None¶: Superelement ID

type = 'GRDSET'¶

uncross_reference() → None[source]¶: Removes cross-reference links

write_card(size: int = 8, is_double: bool = False) → str[source]¶

The writer method used by BDF.write_card

Parameters

sizeint: the size of the card (8/16)

class pyNastran.bdf.cards.nodes.GRID(nid: int, xyz: Union[None, List[float], numpy.ndarray], cp: int = 0, cd: int = 0, ps: str = '', seid: int = 0, comment: str = '')[source]¶

Bases: pyNastran.bdf.cards.base_card.BaseCard

1	2	3	4	5	6	7	8	9
GRID	NID	CP	X1	X2	X3	CD	PS	SEID

Attributes

nidint: node id
xyzfloat ndarray: Raw location <\(x_1, x_2, x_3\)>
cpint: reference coordinate system
cdint: analysis coordinate system
psstr: nodal-based constraints
seidint: superelement id
cp_refCoord() or None: cross-referenced cp
cd_refCoord() or None: cross-referenced cd

Methods

Nid()	gets nid
Cp()	gets cp_ref.cid or cp depending on cross-referencing
Cd()	gets cd_ref.cid or cd depending on cross-referencing
Ps()	gets ps
SEid()	superelement id
get_position()	gets xyz in the global frame
get_position_wrt(model, cid)	gets xyz in a local frame
cross_reference(model)	cross-references the card
uncross_reference()	uncross-references the card
set_position(model, xyz, cid=0, xref=True)	updates the coordinate system
Using the GRID object::	model = read_bdf(bdf_filename) node = model.Node(nid) # gets the position of the node in the global frame node.get_position() node.get_position_wrt(model, cid=0) # gets the position of the node in a local frame node.get_position_wrt(model, cid=1) # change the location of the node node.set_position(model, array([1.,2.,3.]), cid=3)

Creates the GRID card

Parameters

nidint: node id
cpint; default=0: the xyz coordinate frame
xyz(3, ) float ndarray; default=None -> [0., 0., 0.]: the xyz/r-theta-z/rho-theta-phi values
cdint; default=0: the analysis coordinate frame
psstr; default=’’: Additional SPCs in the analysis coordinate frame (e.g. ‘123’). This corresponds to DOF set SG.
seidint; default=0: superelement id TODO: how is this used by Nastran???
commentstr; default=’’: a comment for the card

Cd() → int[source]¶

Gets the output coordinate system

Returns

cdint: the output coordinate system

Cp() → int[source]¶

Gets the analysis coordinate system

Returns

cpint: the analysis coordinate system

Nid() → int[source]¶

Gets the GRID ID

Returns

nidint: node ID

Ps() → str[source]¶

Gets the GRID-based SPC

Returns

psstr: the GRID-based SPC

SEid() → int[source]¶

Gets the Superelement ID

Returns

seidint: the Superelement ID

classmethod add_card(card: BDFCard, comment: str = '') → Any[source]¶

Adds a GRID card from BDF.add_card(...)

Parameters

cardBDFCard(): a BDFCard object
commentstr; default=’’: a comment for the card

cross_reference(model: BDF, grdset: Optional[Any] = None) → None[source]¶

Cross links the card so referenced cards can be extracted directly

Parameters

modelBDF(): the BDF object
grdsetGRDSET / None; default=None: a GRDSET if available (default=None)
.. note:: The gridset object will only update the fields that: have not been set

classmethod export_to_hdf5(h5_file, model, nids)[source]¶: exports the nodes in a vectorized way

get_position() → numpy.ndarray[source]¶

Gets the point in the global XYZ coordinate system.

Returns

xyz(3, ) float ndarray: the position of the GRID in the global coordinate system

get_position_assuming_rectangular() → NDArray3float[source]¶

Gets the point in a coordinate system that has unit vectors in the referenced coordinate system, but is not transformed from a cylindrical/spherical system. This is used by cards like CBAR/CBEAM for element offset vectors.

Returns

xyz(3, ) float ndarray: the position of the GRID in the global coordinate system

get_position_no_xref(model: Any) → numpy.ndarray[source]¶

get_position_wrt(model: BDF, cid: int) → np.ndarray[source]¶

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

Parameters

modelBDF(): the BDF object
cidint: the desired coordinate ID

Returns

xyz(3, ) float ndarray: the position of the GRID in an arbitrary coordinate system

get_position_wrt_coord_ref(coord_out: CORDx) → np.ndarray[source]¶

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

Parameters

coord_outCORDx: the desired coordinate system

Returns

xyz(3, ) float ndarray: the position of the GRID in an arbitrary coordinate system

get_position_wrt_no_xref(model: BDF, cid: int) → NDArray3float[source]¶: see get_position_wrt

raw_fields() → List[Any][source]¶

Gets the fields in their unmodified form

Returns

fieldsList[int/float/str]: the fields that define the card

repr_fields() → List[Any][source]¶

Gets the fields in their simplified form

Returns

fieldsList[int/float/str]: the fields that define the card

set_position(model: BDF, xyz: np.ndarray, cid: int = 0, xref: bool = True) → None[source]¶

Updates the GRID location

Parameters

xyz(3, ) float ndarray: the location of the node.
cpint; default=0 (global): the analysis coordinate system
xrefbool; default=True: cross-references the coordinate system

type = 'GRID'¶

uncross_reference() → None[source]¶: Removes cross-reference links

validate() → None[source]¶: card checking method that should be overwritten

write_card(size: int = 8, is_double: bool = False) → str[source]¶

The writer method used by BDF.write_card

Parameters

sizeint; default=8: the size of the card (8/16)
is_doublebool; default=False: should this card be written with double precision

Returns

msgstr: the card as a string

write_card_16(is_double: bool = False) → str[source]¶: Writes a GRID card in 16-field format

write_card_8() → str[source]¶: Writes a GRID card in 8-field format

class pyNastran.bdf.cards.nodes.GRIDB(nid, phi, cd, ps, ringfl, comment='')[source]¶

Bases: pyNastran.bdf.cards.base_card.BaseCard

defines the GRIDB class

Creates the GRIDB card

Cd()[source]¶

Gets the output coordinate system

Returns

cdint: the output coordinate system

classmethod add_card(card, comment='')[source]¶

Adds a GRIDB card from BDF.add_card(...)

Parameters

cardBDFCard(): a BDFCard object
commentstr; default=’’: a comment for the card

get_position()[source]¶

nid = None¶: node ID

ps = None¶: local SPC constraint

raw_fields()[source]¶

Gets the fields in their unmodified form

Returns

fieldsList[varies]: the fields that define the card

repr_fields()[source]¶

Gets the fields in their simplified form

Returns

fieldsList[varies]: the fields that define the card

ringfl = None¶: ringfl

type = 'GRIDB'¶

write_card(size: int = 8, is_double: bool = False) → str[source]¶

The writer method used by BDF.write_card

Parameters

sizeint; default=8: the size of the card (8/16)
is_doublebool; default=False: should this card be written with double precision

Returns

msgstr: the card as a string

class pyNastran.bdf.cards.nodes.POINT(nid: int, xyz: Union[List[float], numpy.ndarray], cp: int = 0, comment: str = '')[source]¶

Bases: pyNastran.bdf.cards.base_card.BaseCard

1	2	3	4	5	6
POINT	NID	CP	X1	X2	X3

Creates the POINT card

Parameters

nidint: node id
xyz(3, ) float ndarray; default=None -> [0., 0., 0.]: the xyz/r-theta-z/rho-theta-phi values
cpint; default=0: coordinate system for the xyz location
commentstr; default=’’: a comment for the card

Cp() → int[source]¶

Gets the analysis coordinate system

Returns

cpint: the analysis coordinate system

classmethod _init_from_empty()[source]¶

classmethod add_card(card: BDFCard, comment: str = '') → POINT[source]¶

Adds a POINT card from BDF.add_card(...)

Parameters

cardBDFCard(): a BDFCard object
commentstr; default=’’: a comment for the card

cp = None¶: Grid point coordinate system

cross_reference(model: BDF) → None[source]¶

Cross links the card so referenced cards can be extracted directly

Parameters

modelBDF(): the BDF object

get_position() → NDArray3float[source]¶

Gets the point in the global XYZ coordinate system.

Returns

position(3,) float ndarray: the position of the POINT in the globaly coordinate system

get_position_wrt(model, cid)[source]¶

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

Parameters

modelBDF(): the BDF model object
cidint: the desired coordinate ID

Returns

xyz(3,) ndarray: the position of the POINT in an arbitrary coordinate system

nid = None¶: Node ID

raw_fields() → List[Union[int, float, str, None]][source]¶

Gets the fields in their unmodified form

Returns

fieldslist[varies]: the fields that define the card

repr_fields() → List[Union[int, float, str]][source]¶

Gets the fields in their simplified form

Returns

fieldslist[varies]: the fields that define the card

set_position(model, xyz, cid=0)[source]¶

Updates the POINT location

Parameters

xyz(3,) float ndarray: the location of the node
cpint; default=0 (global): the analysis coordinate system

type = 'POINT'¶

uncross_reference() → None[source]¶: Removes cross-reference links

validate() → None[source]¶: card checking method that should be overwritten

write_card(size: int = 8, is_double: bool = False) → str[source]¶

The writer method used by BDF.write_card

Parameters

sizeint: the size of the card (8/16)

xyz = None¶: node location in local frame

class pyNastran.bdf.cards.nodes.SEQGP(nids, seqids, comment='')[source]¶

Bases: pyNastran.bdf.cards.base_card.BaseCard

defines the SEQGP class

Creates the SEQGP card

Parameters

nidint: the node id
seqidint/float: the superelement id
commentstr; default=’’: a comment for the card

classmethod _init_from_empty()[source]¶

classmethod add_card(card, comment='')[source]¶

Adds a SEQGP card from BDF.add_card(...)

Parameters

cardBDFCard(): a BDFCard object
commentstr; default=’’: a comment for the card

append(seqgp)[source]¶

cross_reference(model: BDF) → None[source]¶

raw_fields()[source]¶

Gets the fields in their unmodified form

Returns

fieldsList[varies]: the fields that define the card

type = 'SEQGP'¶

write_card(size: int = 8, is_double: bool = False) → str[source]¶

The writer method used by BDF.write_card

Parameters

sizeint; default=8: unused
is_doublebool; default=False: unused

class pyNastran.bdf.cards.nodes.SPOINT(nid, comment='')[source]¶

Bases: pyNastran.bdf.cards.nodes.XPoint

defines the SPOINT class

Creates the SPOINT card

Parameters

nidint: the SPOINT id
commentstr; default=’’: a comment for the card

get_position()[source]¶

type = 'SPOINT'¶

class pyNastran.bdf.cards.nodes.SPOINTs(ids, comment='')[source]¶

Bases: pyNastran.bdf.cards.nodes.XPoints

1	2	3	4	5	6	7	8	9
SPOINT	ID1	THRU	ID2
SPOINT	ID1	ID1	ID3	ID4	ID5	ID6	ID7	ID8
	ID8	etc.

Creates the SPOINTs card that contains many SPOINTs

Parameters

idsList[int]: SPOINT ids
commentstr; default=’’: a comment for the card

create_spointi()[source]¶: Creates individal SPOINT objects

type = 'SPOINT'¶

class pyNastran.bdf.cards.nodes.XPoint(nid, comment)[source]¶

Bases: pyNastran.bdf.cards.base_card.BaseCard

common class for EPOINT/SPOINT

classmethod _export_to_hdf5(h5_file, model: BDF, nids: List[int]) → None[source]¶: exports the nodes in a vectorized way

classmethod _init_from_empty()[source]¶

cross_reference(model: BDF) → None[source]¶

Cross links the card so referenced cards can be extracted directly

Parameters

modelBDF(): the BDF object

raw_fields()[source]¶

Gets the fields in their unmodified form

Returns

fieldsList[varies]: the fields that define the card

property type¶: dummy method for EPOINT/SPOINT classes

write_card(size: int = 8, is_double: bool = False) → str[source]¶

The writer method used by BDF.write_card

Parameters

sizeint; default=8: unused
is_doublebool; default=False: unused

class pyNastran.bdf.cards.nodes.XPoints(ids, comment='')[source]¶

Bases: pyNastran.bdf.cards.base_card.BaseCard

common class for EPOINTs and SPOINTs

classmethod _init_from_empty()[source]¶

classmethod add_card(card, comment='')[source]¶

Adds a SPOINT/EPOINT card from BDF.add_card(...)

Parameters

cardBDFCard(): a BDFCard object
commentstr; default=’’: a comment for the card

add_points(sList)[source]¶: Adds more EPOINTs/SPOINTs to this object

cross_reference(model: BDF) → None[source]¶

Cross links the card so referenced cards can be extracted directly

Parameters

modelBDF(): the BDF object

raw_fields()[source]¶

Gets the fields in their unmodified form

Returns

fieldsList[varies]: the fields that define the card

property type¶: dummy method for EPOINTs/SPOINTs classes

write_card(size: int = 8, is_double: bool = False) → str[source]¶

The writer method used by BDF.write_card

Parameters

sizeint; default=8: unused
is_doublebool; default=False: unused

pyNastran.bdf.cards.nodes.compress_xpoints(point_type: str, xpoints: List[int]) → List[List[int]][source]¶

Gets the SPOINTs/EPOINTs in sorted, short form.

uncompressed: SPOINT,1,3,5 compressed: SPOINT,1,3,5

uncompressed: SPOINT,1,2,3,4,5 compressed: SPOINT,1,THRU,5

uncompressed: SPOINT,1,2,3,4,5,7 compressed: SPOINT,7

SPOINT,1,THRU,5

point_type = ‘SPOINT’ spoints = [1, 2, 3, 4, 5] fields = compressed_xpoints(point_type, spoints) >>> fields [‘SPOINT’, 1, ‘THRU’, 5]

pyNastran.bdf.cards.nodes.write_xpoints(cardtype: str, points, comment: str = '') → str[source]¶: writes SPOINTs/EPOINTs

nodes Module¶

`nodes` Module¶