femap-neutral-parser 0.4.0

FEMAP neutral file parser

FEMAP neutral Parser

FEMAP neutral file parser

• Free software: MIT license

Features and limitations

Parse and render FEMAP neutral files. For now, three blocks are interpreted:

• Block 100 “Neutral File Header”

• Block 450 “Output Sets”

• Block 451 “Output Data Vectors”

Additionally, MYSTRAN outputs (which makes use of different titles than FEMAP) are harmonized: access to total translation is done using the same title as FEMAP (“Total Translation” vs “RSS translations”).

Basic example

>>> from femap_neutral_parser import Parser
>>> neutral = Parser("fea.NEU")

Get a summary of what’s available:

>>> neutral.info()
Analysis
========
 * subcase 1: Analyse. NASTRAN SPC 1 - NASTRAN SPC 1 - NASTRAN SPC 1 - lc1. test (Static)
 * subcase 2: Analyse. NASTRAN SPC 1 - NASTRAN SPC 1 - NASTRAN SPC 1 - lc2. test (Static)

Outputs
=======
access to one of them using `.output_vectors[<title>][<subcaseid>]['record']

 * Total Translation
 * T1 Translation
 * T2 Translation
...

As of femap-neutral-parser 0.3.0, an aggregated output is done via Parser.vectors() method:

>>> arr = neutral.vectors(("T1 Translation",
...                        "T2 Translation",
...                        "T3 Translation"),
...                       subcaseids=None)  # collect all subcases
>>> arr
rec.array([( 1,  0.        , 0.,  0.000000e+00, 1),
           ( 2, -0.1870816 , 0.,  0.000000e+00, 1),
           ( 3,  0.        , 0.,  0.000000e+00, 1),
           ...
           (10,  0.        , 0., -1.100510e+00, 2),
           (11,  0.        , 0., -1.916094e+00, 2),
           (12,  0.        , 0., -2.389742e+00, 2)],
          dtype=[('nodeID', '<i8'), ('T1 Translation', '<f8'), ('T2 Translation', '<f8'), ('T3 Translation', '<f8'), ('subcaseID', '<i8')])

Which is easily turned into a pandas DataFrame:

>>> pd.DataFrame(arr).set_index(["subcaseID", "nodeID"])
                  T1 Translation  T2 Translation  T3 Translation
subcaseID nodeID
1         1             0.000000             0.0        0.000000
          2            -0.187082             0.0        0.000000
...
          11            0.000000             0.0       -1.564502
          12            0.000000             0.0       -1.602912
2         1             0.000000             0.0        0.000000
          2            -0.204539             0.0        0.000000
...
          11            0.000000             0.0       -1.916094
          12            0.000000             0.0       -2.389742

To get individual output vectors, just address the relevant dictionary:

>>> arr = neutral.output_vectors["Total Translation"][2]["record"]
>>> type(arr)
numpy.ndarray
>>> arr
array([( 1, 0.000000e+00), ( 2, 2.045391e-01), ( 3, 0.000000e+00),
       ( 4, 1.468270e-02), ( 5, 9.231050e-05), ( 6, 6.276400e-01),
       ( 7, 2.578386e+00), ( 8, 1.025100e-01), ( 9, 2.578363e+00),
       (10, 1.100510e+00), (11, 1.916094e+00), (12, 2.389742e+00)],
      dtype=[('nodeID', '<i8'), ('Total Translation', '<f8')])
>>> import pandas as pd
>>> pd.DataFrame(arr).set_index("nodeID")
        Total Translation
nodeID
1                0.000000
2                0.204539
3                0.000000
4                0.014683
5                0.000092
6                0.627640
7                2.578386
8                0.102510
9                2.578363
10               1.100510
11               1.916094
12               2.389742

Requirements

Beside Python>=3.8, only numpy is required. numpy arrays are released as https://numpy.org/doc/stable/user/basics.rec.html, which makes conversions to Pandas a breeze.

Testing

For testing, making docs or coding, all the dev requirements are provided in requirements_dev.txt.

From a blank virtual environment, clone this repo:

git clone https://framagit.org/numenic/femap_neutral_parser.git

Create a Python virtual environment, and activate it:

python3 -m venv fnp
source fnp/bin/activate

Install requirements::

cd femap_neutral_parser pip install -r requirements.txt # install numpy pip install -r requirements_dev.txt pip install -e . # install femap-neutral-parser in new venv

Now testing:

make test  # or make coverage

Building docs:

make docs

History

0.1.0 (2021-03-24)

• First release on PyPI.

0.2.0 (2021-04-16)

• Update Documentation