Xara

<p align="center"> <a href="https://xara.so/"> <img src="https://raw.githubusercontent.com/STAIRLab/xara-docs/master/source/_static/images/xara-chi.png" alt="xara logo" width="150" > </a> </p> <hr> <!-- <h3 align="center">xara</h3> --> <p align="center"> Nonlinear finite element analysis. <br> </p> <img align="left" src="https://raw.githubusercontent.com/claudioperez/sdof/master/docs/assets/peer-black-300.png" width="150px" alt="PEER Logo"> <br> <div style="align:center">

</div>

xara is a Python package that provides an intuitive and performant API for nonlinear
finite element analysis, implemented in C++ through the OpenSeesRT framework.
OpenSees features state-of-the-art finite element formulations and solution
algorithms, including mixed formulations for beams and solids, over 200 material models, and an
extensive collection of continuation algorithms to solve highly nonlinear
problems.

This package may be used as a drop-in replacement for both OpenSees.exe and
OpenSeesPy (see Getting Started below), and generally provides a substantial performance boost.

Getting Started

The xara package can be installed into a Python environment
in the standard manner. For example, using pip:

shellCopy
pip install xara

There are several ways to use the xara package:

• The standard way to use xara from Python is to create a xara.Model,
  and invoke its methods:

  pythonCopy
  model = xara.Model(ndm=2, ndf=2) # Create a 2D model with 2 DOFs per node
  model.node(1, 2.0, 3.0)
  ...

  Most of the functions from the OpenSeesPy library can be invoked directly
  as methods of a xara.Model without any changes in syntax, although it is
  generally encouraged to use the safer variants supported by xara. For
  example:

  pythonCopy
  # BAD
  model.pattern("Plain", 1, "Linear")
  model.load(1, 2.0, 3.0)
  # GOOD
  model.pattern("Plain", 1, "Linear")
  model.load(1, 2.0, 3.0, pattern=1)

• To start an interactive Tcl interpreter run the shell command:

  bashCopy
  python -m opensees

  To quit the interpreter, just run exit:

  tclCopy
  opensees > exit

• To execute Tcl procedures programmatically from Python, create an instance
  of the xara.Model class and call its eval() method to evaluate Tcl code:

  pythonCopy
  model = xara.Model()
  model.eval("model Basic -ndm 2")
  model.eval("print -json")

• The xara package exposes a compatibility layer that exactly reproduces
  the OpenSeesPy functions, but does so without mandating a single
  global program state. To run OpenSeesPy scripts, just change the import:

  pythonCopy
  import openseespy.opensees

  to

  pythonCopy
  import opensees.openseespy

  For true stateless modeling, the Model class should be used instead of the legacy
  model function; see the documentation here.

Development

To compile the project see about/compiling

Support

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