Dynamic is a simple simulator for dynamical systems construed as computations. See the project homepage for links to related publications.
The following information may also be found in the file LICENSE.txt.
Except as stated below, all files in this repository are Copyright ©2017 Sandia Corporation. Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains certain rights in this software.
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
Certain third-party software is included in this package and carries its own separate copyright and licensing terms. See the file NOTICE.txt for details.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
The present version number designation of Dynamic is 0.1 (alpha). The status of this software should be considered PRE-RELEASE. It is still in early development. User-friendly visualization and configuration features have still not been implemented.
Dynamic is a framework for simulating simple models of (conservative, nonlinear, generally chaotic) dynamical systems, for the purpose of investigating to what extent such models can be used as the foundation for new computational paradigms.
Dynamic provides for the construction and simulation of arbitrary networks (undirected graphs) of canonical coordinates, coupled to their neighbors by arbitrary Hamiltonian interaction terms. The simulation method does discrete time-domain integration using a centered-difference leapfrog-style update rule, alternating between position and momentum coordinates. Coordinates are represented in fixed point. Together the centered-difference update rule and the fixed-point coordinates ensure complete bit-level reversibility of the simulation, ensuring that the simulated time-evolution does not destroy entropy.
The initial prototype implementation of Dynamic is being written in Python (3.5.1) and tested on Windows (8.1 Professional, 64-bit), although we may eventually port it to C++ for better performance, and/or perhaps code a parallel version using MPI and/or OpenMP.
We plan to support a variety of interactive, animated views of the data for visualization and analysis purposes. Some possibilities for this may include:
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Plot position/velocity (phase portrait) of each coordinate on a 2D plane. Animate fading trails showing coordinate history. Plot mean/deviation of coordinate values.
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Plot circuit diagram color-coding node values. Overlay inferred digital values?
The present status of the development of the visualization capabilities is: A window is created for visualization purposes, but nothing is displayed in it yet. More work is needed...
Dynamic will be able to be configured to connect important statistics about the trajectories of coordinates of interest in the system, for purposes of analyzing whether computationally meaningful information is contained in the trajectory.
Presently, the demo applications calculates and displays mean values of the generalized position coordinate of each node.
For notes on the software architecture of Dynamic, see the docs/Notes.txt file.
Contents of the 'dynamic/' repository are as follows:
9.1. Artwork subdirectory (artwork/).
Contains source files and high-resolution reference versions of graphic artwork for the Dynamic system (splash pages, logos, etc.).
9.2. Batch subdirectory (batch/).
Contains MS-DOS style batch (.BAT) files to facilitate working with the source tree in Windows environments.
9.3. Data subdirectory (data/).
Contains various raw output data from the simulation as well as Excel workbooks.
9.4. Documentation subdirectory (docs/).
Contains miscellaneous notes and other documentation.
9.5. Log subdirectory (log/).
This directory is initially empty and exists solely to be the location where log files will be written.
9.6. Main source file hierarchy (src/).
Current source file tree.
9.7. Test directory (test/).
Auxilliary source files for testing.
9.8. Copyright/license files (LICENSE.txt, NOTICE.txt).
The main copyright/license file is LICENSE.txt. An additional
notice relevant to incorporated third-party software is in NOTICE.txt.
9.9. README file (README.md).
This file.