Indices and tables¶
Overview¶
pycvodes provides a
Python binding to the
Ordinary Differential Equation
integration routines from cvodes in the
SUNDIALS suite. pcyvodes allows a user to numerically integrate
(systems of) differential equations. Note that routines for sensitivity analysis is not yet exposed in this binding (which makes
the functionality essentially the same as cvode).
The following multistep methods are available:
- bdf
- adams
Note that bdf (as an implicit stepper) require a user supplied callback for calculating the jacobian.
Documentation¶
Autogenerated API documentation for latest stable release is found here: https://pythonhosted.org/pycvodes (and development docs for the current master branch are found here: http://hera.physchem.kth.se/~pycvodes/branches/master/html).
Installation¶
Simplest way to install is to use the conda package manager:
$ conda install -c bjodah pycvodes pytest
$ python -m pytest --pyargs pycvodes
tests should pass.
Binary distribution is available here: https://anaconda.org/bjodah/pycvodes
Source distribution is available here: https://pypi.python.org/pypi/pycvodes
Examples¶
The classic van der Pol oscillator (see examples/van_der_pol.py)
>>> import numpy as np
>>> from pycvodes import integrate_predefined # also: integrate_adaptive
>>> mu = 1.0
>>> def f(t, y, dydt):
... dydt[0] = y[1]
... dydt[1] = -y[0] + mu*y[1]*(1 - y[0]**2)
...
>>> def j(t, y, Jmat, dfdt=None, fy=None):
... Jmat[0, 0] = 0
... Jmat[0, 1] = 1
... Jmat[1, 0] = -1 - mu*2*y[1]*y[0]
... Jmat[1, 1] = mu*(1 - y[0]**2)
... if dfdt is not None:
... dfdt[:] = 0
...
>>> y0 = [1, 0]; dt0=1e-8; t0=0.0; atol=1e-8; rtol=1e-8
>>> tout = np.linspace(0, 10.0, 200)
>>> yout, info = integrate_predefined(f, j, y0, tout, atol, rtol, dt0,
... method='bdf')
>>> import matplotlib.pyplot as plt
>>> series = plt.plot(tout, yout)
>>> plt.show()
For more examples see examples/, and rendered jupyter notebooks here: http://hera.physchem.kth.se/~pycvodes/branches/master/examples
License¶
The source code is Open Source and is released under the simplified 2-clause BSD license. See LICENSE for further details.
Contributors are welcome to suggest improvements at https://github.com/bjodah/pycvodes