deltasigma 0.2.2

a Python package to synthesize, simulate, scale and map to implementable topologies delta sigma modulators.

A port of the MATLAB Delta Sigma Toolbox based on free software and very little sleep

The python-deltasigma is a Python package to synthesize, simulate, scale and map to implementable topologies delta sigma modulators.

It aims to provide a 1:1 Python port of Richard Schreier’s *excellent* MATLAB Delta Sigma Toolbox, the de facto standard tool for high-level delta sigma simulation, upon which it is very heavily based.

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Homepage: python-deltasigma.io

Documentation: docs.python-deltasigma.io

Latest version: 0.2

Install

python-deltasigma runs on Linux, Mac OS X and Windows.

Installing requires Python 2.6+ or 3.3+, numpy, scipy (>= 0.11.0) and matplotlib.

Strongly recommended: Cython - for significantly faster delta sigma modulator simulations.

They are packaged by virtually all the major Linux distributions.

I do not run Windows, so I can’t really provide more info (sorry), except that people tell me they manage to have a working setup.

When the dependencies are satisfied, run:

pip install deltasigma

to install the latest stable version from the Python Package Index (PYPI), or:

python setup.py install

if you’re installing a development version from Git.

Extras

Install the sphinx package to build the documentation yourself.

The test suite requires setuptools, used to access the reference function outputs.

Testing can be automated with nose and triggered with:

python setup.py test

Documentation

In addition to the notebooks found in the examples/ directory, ported from the MATLAB Delta Sigma toolbox:

1. You can find the included package documentation online.

2. The original MATLAB Toolbox provides in-depth documentation, which is very useful to understand what the toolbox is capable of. See DSToolbox.pdf and OnePageStory.pdf (PDF warning).

3. The book:

   Richard Schreier, Gabor C. Temes, Understanding Delta-Sigma Data Converters, ISBN: 978-0-471-46585-0, November 2004, Wiley-IEEE Press

   is probably the most authoritative resource on the topic. Chapter 8-9 show how to use the MATLAB toolkit and the observations apply also to this Python port. Links on amazon, on the Wiley-IEEE press.

   I am not affiliated with neither the sellers nor the authors.

Licensing and copyright notice

All original MATLAB code is Copyright (c) 2009, Richard Schreier. See the LICENSE file for the licensing terms.

The Python code here provided is a derivative work from the above toolkit - a faithful port - and subject to the same license terms.

Credit goes to Richard Schreier for writing the MATLAB Delta Sigma Toolbox, devising algorithms and implementations and doing an excellent work at it.

This package contains some source code from pydsm, also based on the same MATLAB toolbox. The pydsm package is copyright (c) 2012, Sergio Callegari.

When not otherwise specified, the Python code is Copyright 2013, Giuseppe Venturini and the python-deltasigma contributors.

MATLAB is a registered trademark of The MathWorks, Inc.

CHANGES

Version 0.2 series

The 0.2 series features support for real and quadrature baseband and passband modulator topologies.

0.2.2: Add support for scipy 0.16.x.

• scipy introduced several subclasses for scipy.signal.lti, they are now supported.

• BUGFIX: Merge pull request from Thomas Russell Murphy, fixing an off-by-one slicing error in dsdemo3 (great catch! thanks you).

• Fix typos in the documentation.

0.2.1: Fix calculation of quadrature STFs.

• BUGFIX: Fix calculation of quadrature STFs from their ABCD matrix.

• Add dsexample4.ipynb to the examples.

0.2.0: Add support for quadrature modulators.

• Add simulateQDSM(),

• Add synthesizeQNTF(),

• Add realizeQNTF(),

• Add simulateQSNR(),

• Add calculateQTF().

• Several functions have been extened to support quadrature modulator.

Version 0.1 series

0.1-10: Bugfix and additional options in changeFig().

• BUGFIX: ship Cython sources in the package.

• BUGFIX: only modify explicitely set options in changeFig().

• Add support for xfticks and yfticks options in changeFig().

• Add support for BW conversion of plots in changeFig().

0.1-9: Add support for modulators with multiple outputs, allowing simulating MASH cascade DSMs.

• Add support in partitionABCD() for specifying the number of outputs.

• Add support for multiple quantizers in calculateTF().

• BUGFIX: Fix simulation of DSMs with multiple quantizers.

• BUGFIX: cancelPZ() was not testing the first root.

• pretty_lti() now returns 0 if k is 0 after rounding.

• plotPZ() doesn’t list coincident real roots as complex conjugate roots with imag(root) = +/-0.

• DOC: add example of MASH cascade.

0.1-8: Accept both tuples and lists as NTFs for simulation.

• Previously passing a tuple for the NTF resulted in an error. Fixed.

• Doc fixes in mapCtoD().

0.1-7: Quantization fix in the Cython backends. More tests.

• A bug was found in the function responsible for quantizing the loop filter output in simulateDSM(), only the Cython implementations are affected: all users are strongly recommended to upgrade.

• Add more test for simulateDSM().

• Check for the filter and data lengths in sinc_decimate().

0.1-6: sinc_decimate() fix, NTF matching method in realizeNTF_ct()

• An off-by-1 indexing bug was found in sinc_decimate(), all users are strongly recommended to update.

• Add NTF matching method to realizeNTF_ct().

0.1-5: CRFFD support, separate tests, less verbosity and DOC fixes.

• Add CRFFD support (see realizeNTF, mapABCD and stuffABCD).

• Move all tests to a dedicated location (tests/).

• Ensure float64 is the data representation when simulating DSM.

• Add the simulations_backends variable and its doc.

• Cython: disable cblas extension on Win. Reduce verbosity.

• Multiple minor fixes to ensure scalars are never returned in place of arrays.

Many thanks to Shayne Hodge for reporting issues with deltasigma on Windows and several patches to the test suite.

0.1-4: Cython implementation of simulateDSM(), PEP8 and DOC fixes.

• deltasigma/_simulateDSM_cblas.pyx and deltasigma/_simulateDSM_scipy_blas.pyx, Cython implementation from pydsm of simulateDSM(), available if Cython is, providing a 70x speed-up of DSM simulations.

• More documentation improvements and PEP8-related fixes.

0.1-3: Bugfixes, PEP8, more test coverage

• deltasigma/_realizeNT_ct.py now supports FF topologies.

• deltasigma/_pulse.py now supports MIMO systems.

• pretty_lti() has been improved to provide the prettiest printing of LTIs to date.

• Many documentation improvements and PEP8-related fixes.

0.1-2: Bugfixes, PEP8, DOC and most importantly a, g, b, c reshape.

• The a, g, b, c coefficients are now 1-dimensional.

• deltasigma/_stuffABCD.py: scalar b bugfix.

• deltasigma/_logsmooth.py: fix bin width.

• deltasigma/_utils.py: add mround(), round compatibly with MATLAB.

• deltasigma/_utils.py: add root multiplicity support in pretty_lti().

• deltasigma/_utils.py: bugfix in cplxpair for incoherent complex values.

0.1-1: Bugfix: most importantly fix realizeNTF_ct().

• deltasigma/_realizeNTF_ct.py: Fixes for multi-timing, add unit tests for FB.

• deltasigma/_pulse.py: Bugfix (reshape missing assignment), fix documentation formatting.

• deltasigma/_bilogplot.py: Fix plot. Add unit test.

• deltasigma/_rmsGain.py: Fix docstring.

• deltasigma/_lollipop.py: Use matplotlib’s stem function. Enforce PEP8. Add support for color ‘None’.

0.1: Bugfix: missing copy() in mapABCD().

0.1rc4 : Multiple bugfixes. Py3k fixes. Test coverage up to 85+%.

0.1rc3 : Fix file-not-found issue with setup.py.

0.1rc2 : Fix travis and coveralls.io support.

0.1rc1 : Initial release