pyiga is a Python research toolbox for Isogeometric Analysis. Its current highlights are:
- Automatic generation of efficient matrix assembling code from a high-level, FEniCS-like description of the bilinear form. See the bottom of vform.py for some built-in examples as well as the Navier-Stokes example below.
- Fast assembling by a black-box low-rank assembling algorithm described in this paper (or this technical report).
- Extensive support for fast tensor approximation methods for tensor product IgA.
To find out more, have a look at the API reference and the examples below.
The notebooks directory contains several examples of how to use pyiga:
- solve-poisson.ipynb: solve a Poisson equation and plot the solution
- solve-stokes.ipynb: solve stationary Stokes flow and plot the velocity field
- solve-navier-stokes.ipynb: solve the instationary Navier-Stokes equations with fully implicit Crank-Nicolson timestepping and produce an animation of the result
pyiga is compatible with Python 2.7 as well as Python 3.4 and higher.
NB: Python 2 support is only provided for compatibility and is not
well tested. Python 3 is recommended.
Before installing, make sure you have recent versions of Numpy, Scipy and Cython installed and that your environment can compile Python extension modules. If you do not have such an environment set up yet, the easiest way to get it is by installing Anaconda (this can be done without administrator privileges).
Clone this repository and execute
$ python setup.py install --user
in the main directory. The installation script should now compile the Cython
extensions and then install the package in your user directory. If you prefer
to install the package globally, skip the --user flag; this requires
administrator rights.
If you have Intel MKL installed on your machine, be sure to install the
pyMKL package; if pyiga detects this package, it will use the
MKL PARDISO sparse direct solver instead of the internal scipy solver
(typically SuperLU).
pyiga comes with a small test suite to test basic functionality. Depending on
your test runner of choice, move to the main directory and execute
nosetests or py.test to run the tests.
If the test runner fails to find the Cython extensions modules (pyiga.bspline_cy etc.),
you may have to run python setup.py build_ext -i to build them in-place.
After successful installation, you should be able to load the package. A simple example:
from pyiga import bspline, geometry, assemble
kv = bspline.make_knots(3, 0.0, 1.0, 50) # knot vector over (0,1) with degree 3 and 50 knot spans
geo = geometry.quarter_annulus() # a NURBS representation of a quarter annulus
K = assemble.stiffness((kv,kv), geo=geo) # assemble a stiffness matrix for the 2D tensor product
# B-spline basis over the quarter annulusThere is an API reference. Beyond that, look at the code, the unit tests, and the IPython notebooks to learn more.