(py)oscode: Oscillatory ordinary differential equation solver¶
oscode is a C++ tool with a Python interface that solves oscillatory
ordinary differential equations efficiently. It is designed to
deal with equations of the form
where \(\gamma(t)\) and \(\omega(t)\) can be given as arrays.
oscode makes use of an analytic approximation of \(x(t)\) embedded in a
stepping procedure to skip over long regions of oscillations, giving a reduction
in computing time. The approximation is valid when the frequency
\(\omega(t)\) changes slowly relative to the timescales of integration, it
is therefore worth applying when this condition holds for at least some part of
the integration range.
For the details of the numerical method used by
oscode, see the Citations
Basic requirements for using the C++ interface:
C++11 or later
Eigen (a header-only library included in this source)
The strictly necessary Python dependencies are automatically installed when you use pip or the setup.py. They are:
The optional dependencies are:
pyoscode can be installed via pip
pip install pyoscode
or via the setup.py
git clone https://github.com/fruzsinaagocs/oscode cd oscode python setup.py install --user
You can then import
pyoscode from anywhere. Omit the
--user option if
you wish to install globally or in a virtual environment. If you have any
difficulties, check out the FAQs section below.
You can check that things are working by running tests/ (also ran by Travis continuous integration):
oscode is a header-only C++ package, it requires no installation.
git clone https://github.com/fruzsinaagocs/oscode
and then include the relevant header files in your C++ code:
#include "solver.hpp" #include "system.hpp"
Try the following quick examples. They are available in the examples.
- Introduction to oscode
- To plot results from burst.cpp
To compile and run:
g++ -g -Wall -std=c++11 -c -o burst.o burst.cpp g++ -g -Wall -std=c++11 -o burst burst.o ./burst
Documentation is hosted at readthedocs.
To build your own local copy of the documentation you can run:
cd pyoscode/docs make html
If you use
oscode to solve equations for a publication, please cite:
Any comments and improvements to this project are welcome. You can contribute by:
Opening and issue to report bugs and propose new features.
Making a pull request.
You can get help by submitting an issue or posting a message on Gitter.
- Eigen import errors:
pyoscode/_pyoscode.hpp:6:10: fatal error: Eigen/Dense: No such file or directory #include <Eigen/Dense> ^~~~~~~~~~~~~
Try explicitly including the location of your Eigen library via the
CPLUS_INCLUDE_PATHenvironment variable, for example:
CPLUS_INCLUDE_PATH=/usr/include/eigen3 python setup.py install --user # or CPLUS_INCLUDE_PATH=/usr/include/eigen3 pip install pyoscode
/usr/include/eigen3should be replaced with your system-specific eigen location.
Many thanks to Will Handley, Lukas Hergt, Anthony Lasenby, and Mike Hobson for their support and advice regarding the algorithm behind oscode. There are many packages without which some part of oscode (e.g. testing and examples) wouldn’t run as nicely and smoothly, thank you all developers for making and maintaining these open-source projects. A special thanks goes to the devs of exhale for making the beautiful C++ documentation possible.
- 1.0.0: current version
Arrays for frequency and damping term need not be evenly spaced
Automatic C++ documentation on readthedocs
Eigen included in source for pip installability
First pip release :)
Bug that occurred when beginning and end of integration coincided corrected
Automatic detection of direction of integration
Memory leaks at python interface fixed
C++ documentation added