ExaDisNet Class¶
Description¶
ExaDisNet
is the fundamental data structure used in pyexadis
(python interface to ExaDiS) to represent the dislocation network. ExaDisNet
is a wrapper class around the internal data structure representation of the dislocation network in ExaDiS, which internally handles memory movements between the different execution spaces (e.g. CPU to GPU).
An ExaDisNet
network can be instantiated in several ways. The native way is to provide a cell, an array of nodes, and an array of segments as arguments:
G = ExaDisNet(cell, nodes, segs)
with
cell
:pyexadis.Cell
object defining the simulation cell. Constructor arguments:h
(required): simulation cell matrix (columns are the cell vectors)origin
(optional): cell origin. Default: (0,0,0)is_periodic
(optional): periodic flag along the three dimensions. Default: [true,true,true].
nodes
: array of nodes where each row contains a node attributes.Attributes for all nodes must be of the following formats:
x, y, z
x, y, z, constraint
domain_id, local_id, x, y, z
domain_id, local_id, x, y, z, constraint
where x, y, z are the nodes coordinates, constraint is the node constraint (
pyexadis_base.NodeConstraints.UNCONSTRAINED
orpyexadis_base.NodeConstraints.PINNED_NODE
), domain_id is the simulation domain index, local_id is the local index of the node in the domain.
segs
: array of segments defining the directed dislocation graph.Segments must be defined only once, e.g. if a segment from node i to node j is defined, then the segment from node j to node i must not be defined.
Attributes of the segments must be of the following formats:
n1, n2, bx, by, bz
n1, n2, bx, by, bz, nx, ny, nz
where n1, n2 are the end nodes indices (index in the
nodes
array), bx, by, bz are components of the Burgers vector when going from node n1 to node n2, nx, ny, nz are components of the segment slip plane normal.
Note that all lengths (e.g. cell size, nodes coordinates, Burgers vectors) are defined in units of global parameter burgmag
. Burgers vectors and plane normals are defined in the global frame of the simulation.
For instance, we can define a dislocation line of length 100b along [1,0,0] lying on plane [0,1,0] and discretized with 3 nodes:
Ldis = 100.0
Lbox = 2*Ldis
cell = pyexadis.Cell(h=Lbox*np.eye(3), origin=-0.5*Lbox*np.ones(3))
nodes = np.array([[-0.5*Ldis, 0.0, 0.0, NodeConstraints.PINNED_NODE],
[ 0.0*Ldis, 0.0, 0.0, NodeConstraints.UNCONSTRAINED],
[ 0.5*Ldis, 0.0, 0.0, NodeConstraints.PINNED_NODE]])
segs = np.array([[0, 1, b[0], b[1], b[2], 0.0, 1.0, 0.0],
[1, 2, b[0], b[1], b[2], 0.0, 1.0, 0.0]])
G = ExaDisNet(cell, nodes, segs)
Some utility functions are also provided in file python/pyexadis_utils.py
to generate basic dislocation graphs (Frank-Read source, infinite lines, etc.). See Creating initial dislocation configurations for more information.
Another convenient method is to initialize a ExaDisNet
object by reading a dislocation network in legacy ParaDiS format from file using built-in method read_paradis()
:
G = ExaDisNet()
G.read_paradis('config.data')
A dislocation network defined in a ExaDisNet
object must be wrapped into a DisNetManager
object before it can be used within modules, e.g.
G = ExaDisNet(...)
N = DisNetManager(G)
Properties¶
ExaDisNet.net
: pointer to the ExaDiS network binding objectExaDisNet.cell
: ExaDiS network cell object
Methods¶
ExaDisNet.import_data(data)
: Set the content of theExaDisNet
object by importing it from adata
dictionary. Argumentdata
must be the output of anexport_data()
method.ExaDisNet.export_data()
: Export theExaDisNet
object into adata
dictionary.ExaDisNet.read_paradis(datafile)
: Set the content of theExaDisNet
object by reading a legacy ParaDiS data file.ExaDisNet.write_data(datafile)
: Write the network into a legacy ParaDiS data file.ExaDisNet.generate_prismatic_config(crystal, Lbox, num_loops, radius, maxseg=-1, Rorient=None, seed=1234, uniform=False)
: Set the content of theExaDisNet
object by generating a configuration made of prismatic dislocation loops.ExaDisNet.generate_line_config(crystal, Lbox, num_lines, theta=None, maxseg=-1, Rorient=None, seed=-1, verbose=True)
: Set the content of theExaDisNet
object by generating a configuration made of straight, infinite lines/dipoles.ExaDisNet.num_nodes()
: Returns the number of nodes in the network.ExaDisNet.num_segments()
: Returns the number of segments in the network.ExaDisNet.is_sane()
: Checks if the network connectivity is sane.ExaDisNet.get_nodes_data()
: Returns a dictionary of nodes data, containing entriestags
,positions
, andconstraints
.ExaDisNet.get_segs_data()
: Returns a dictionary of segments data, containing entriesnodeids
,burgers
, andplanes
.ExaDisNet.get_tags()
: Returns an array of the nodes tags (domain,index), size=(Nnodes,2).ExaDisNet.get_positions()
: Returns an array of the nodes positions, size=(Nnodes,3).ExaDisNet.set_positions(pos)
: Sets the nodes positions by providing arraypos
of size=(Nnodes,3)ExaDisNet.get_forces()
: Returns an array of the nodes forces, size=(Nnodes,3).ExaDisNet.get_velocities()
: Returns an array of the nodes velocities, size=(Nnodes,3).