Reads a mesh from CalcluliX input (.inp) files.
Project description
ccxmeshreader
Introduction
Reads a mesh from CalcluliX input (.inp
) files.
Only supports a limited set of keywords defining the mesh. See Supported Keywords for details.
Usage
from ccxmeshreader import read_mesh
mesh = read_mesh('path/to/some.inp')
Supported Keywords
*NODE
Nodes and their coordinates are parsed and added to the dictionary returned by read_mesh
in the node_coordinates_by_number
key.
The node_coordinates_by_number
key contains a dictionary where the key is the node number, and value is the coordinates as a three-element tuple with float values.
For example, given the following *NODE
definition:
*NODE, NSET=Nall
1, 1.0, 0.0, 0.1
2, 3.0, 1.0, 2.0
3, 0.9, 5.0, 7.0
mesh = read_mesh('example.inp')
print(mesh['node_coordinates_by_number'])
{
1: (1.0, 0.0, 0.1),
2: (3.0, 1.0, 2.0),
3: (0.9, 5.0, 7.0)
}
Currently node sets are not supported, and the optional NSET
parameter is ignored.
*ELEMENT
Elements and their associated nodes are parsed and added to the dictionary returned by read_mesh
in the element_dict_by_type
key.
The element_dict_by_type
key contains a dictionary where the key is the element type, and value is another dictionary where the key is the element number,
and value is a list of node numbers associated to the element.
For example, given the following *ELEMENT
definition:
*ELEMENT, TYPE=C3D20R, ELSET=Eall
1, 1, 2, 3
2, 4, 5, 6
mesh = read_mesh('example.inp')
print(mesh['element_dict_by_type'])
{
'C3D20R': {
1: [1, 2, 3]
2: [4, 5, 6]
}
}
Continuation of data-lines ending with a comma ,
is supported. For example:
*ELEMENT, TYPE=C3D20R, ELSET=Eall
1, 1, 2, 3,
4, 5, 6
2, 7, 8, 9
mesh = read_mesh('example.inp')
print(mesh['element_dict_by_type'])
{
'C3D20R': {
1: [1, 2, 3, 4, 5, 6]
2: [7, 8, 9]
}
}
If the ELSET
parameter is provided, then the element set will be added to the element_set_by_name
dictionary returned in the mesh of read_mesh
with the corresponding element numbers.
For example, from the above *ELEMENT
definition:
mesh = read_mesh('example.inp')
print(mesh['element_set_by_name'])
{
'EALL': {1, 2}
}
*ELSET
Element set definitions are parsed and added to the dictionary returned by read_mesh
in the element_set_by_name
key.
The element_set_by_name
key contains a dictionary where the key is the name of the element set, and value is a set of element numbers.
For example, given the following *ELEMENT
and *ELSET
definitions:
*ELEMENT, TYPE=S4, ELSET=E1
1, 1, 2, 3,
4, 5, 6
2, 7, 8, 9
*ELSET, ELSET=E2, GENERATE
1, 4
*ELSET,ELSET=E3
E2, 5, 6
mesh = read_mesh('example.inp')
print(mesh['element_set_by_name'])
{
'E1': {1, 2},
'E2': {1, 2, 3, 4}
'E3': {1, 2, 3, 4, 5, 6}
}
The optional GENERATE
parameter is respected with start, end, and step.
*INCLUDE
Files specified by the *INCLUDE
keyword are read, but currently limited to relative file paths, and assumed to be relative to the path passed to read_mesh
.
Recursive includes (i.e. *INCLUDE
statements in a previously included file) are not yet supported.
Approach
The approach this library takes is to read the .inp
file in a while
loop, line-by-line, until there are no lines left, and collect the nodes and elements that make up the mesh into a dictionary.
It does not use an intermediate step of parsing the .inp
file into an abstract syntax tree -- as doing so would be costly and likely involve a parsing library.
Thus, ccxmeshreader
can be considered light-weight and performant.
Limitations
Continuation of keyword lines is not supported.
For example, trying to read the following .inp
file:
*ELEMENT, TYPE=C3D20R,
ELSET=Eall
raises a ccxmeshreader.ParserError
.
Unit Tests
Unit tests are included in the tests/
directory, and can be ran with the following command:
python -m unittest discover tests "*_test.py"
Project details
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