Number Crunching and Related Tools

This page lists a number of packages related to numerics, number crunching, signal processing, financial modeling, linear programming, statistics, data structures, date-time processing, random number generation, and crypto.

This list is current as of 25 September 2001.

Cryptography

• mxCrypto [details] [source]
  An extensive toolkit including Python extensions for encryption, authentication, key exchange, secure socket operation, and many other types of cryptography operations. (M.-A. Lemburg)
• Python Cryptography Toolkit [details]
  Contains hashing algorithms, chaffing/winnowing, random number generation, various utility modules, and several block encryption and digital signature algorithms. (A.M. Kuchling)

Data Structures

• PyPolyhedron [details] [source]
  Calculate polyhedron's V- and H-representation. This is a Python interface to a C-library cddlib (Pearu Peterson)
• avl_tree [details] [source]
  AVL module provide a hybrid between a dictionary and a list which can come in handy. AVL trees (named after the inventors, Adel'son-Vel'skii and Landis) are balanced binary search trees. (Sam Rushing)
• bplustree [details] [source]
  Classical compsci B+trees, implemented entirely in Python: Fast, portable file based indexing with range queries and including a dbm-compatibility mode. (Aaron Watters)
• fsm [details] [source]
  Finite State Machine module. (Skip Montanaro)
• graph_lib [details] [source]
  This module defines the Python class Graph. Graph is loosely modelled after the Library of Efficient Data types and Algorithms (LEDA). It includes methods for constructing graphs, BFS and DFS traversals, topological sort, etc.
• kjbuckets [details] [source]
  kjbuckets is a C extension to python which defines three Python data types kjSet, kjGraph, and kjDict, implemented using a fast and space efficient hash table strategy. The types are tightly coupled and may be combined and manipulated using a collection of fast "set at a time" operations written in C. If you need to manipulate collections and mappings quickly take a look at this module. It comes with no warrantee of course, but it has been pounded pretty heavily and I consider it fairly solid. (Aaron Watters)
• npstruct [details] [source]
  An extension module useful for parsing and unparsing binary data structures. Somewhat like the standard struct module, but with a few extra features (bitfields, user-function-fields, byte order specification, etc...) and a different API more convenient for streamed and context-sensitive formats like network protocol packets, image and sound files, etc. (Sam Rushing)

Date/Time

• mxDateTime [details] [source]
  These types were created to provide a consistent way of transferring date and time data between Python and databases. Apart from handling date before the Unix epoch (1.1.1970) they also correctly work with dates beyond the Unix time limit (currently with Unix time values being encoded using 32bit integers, the limit is reached in 2038) and thus is Year 2000 and Year 2038 safe. (M.-A. Lemburg)
• Mayalib [details] [source]
  Mayan dates and numbers (math) for Python. (Ivan Van Laningham)
• normalDate [details] [source]
  NormalDate is a specialized class to handle dates without all the excess baggage (time zones, daylight savings, leap seconds, etc.) of other date structures. (Jeff Bauer)
• strptime [details] [source]
  Produce time-module style time tuples: The inverse of strftime, convert a string to a tuple that the time module can handle. (Andy Eskilsson)

FFT

• Fftw-numpy [details] [source]
  Fftw-numpy is a generic wrapping of the FFTW-2.1.3 C-library into Python done using SWIG. FFTW is advertised as a very fast implementation of the FFT and I believe it lives up to its billing. It has support for arbitrary N-dimensional arrays as well as fast real-to-complex FFT's. As part of the package, I have included a module called FFT2 that can act as a drop-in replacement for FFT in NumPy (except there is no real-to-complex transform yet). There is also a benchmark script that shows that FFT2 is about 18-25% faster than fftpack (at least on pentium machines). There is also support for arbitrary multidimensional transforms (not just 2-D). (Travis Oliphant)
• fourier [details] [source]
  A set of routines to perform Fourier transforms using pure (Numerical) Python. These are slower by a factor of 2-10 than pure C version in the FFT module (which is pretty good for a pure Python solution), but they make an interesting example. (Tom Hochberg)
• Signaltools [details] [source]
  A work in progress toolbox intended to contain most of the signal processing functionality available in other array-oriented systems like MATLAB. the included routines are fast N-D convolution and N-D correlation procedures for use when filtering big datasets with small kernels and a fast N-D order statistic filter routine. (A median filter is an example of an order-filter and is also included). There is also a routine to filter along an arbitrary dimension of an N-D array with a rational transfer function filter (like the filter function in MATLAB) and a remez-exchange algorithm. Recently added are an N-D median filter and an N-D wiener filter. (Travis Oliphant)

Finance

• pyfi [details] [source]
  pyfi provides a set of functions that perform commonly used financial calculations. (Rupert Scammell)
• pyFinancials [details] [source]
  A collection of algorithms for advanced financial calculations. (G. P. Ciceri)

Interface

• Multipack [details] [source]
  A collection of FORTRAN routines interfaced with NumPy. There are modules for special function evaluation, signal and image processing, and modules that wrap common FORTRAN functions from ODEPACK, MINPACK, and QUADPACK. (Travis Oliphant)
• SAML [details] [source]
  Interface to the "Simple Algebraic Math Library", a C library for computer algebra, together with some application programs: a desktop calculator, a spreadsheet (sort of) and a program to factorize integers. (Thierry Bousch)
• pymat [details] [source]
  PyMat is an interface between NumPy and a MATLAB engine session. It can be used to support NumPy's functionality with the features of MATLAB. An example module is included that presents a very simple interface to MATLAB's plotting functions. This allows you to, for example, plot NumPy arrays in a MATLAB plot window. (Andrew Sterian)
• PYML [details] [source]
  PYML is an interface between the computer language Python and Mathematica. Mathematica expressions can be written in Python code, evaluated, and their results returned to Python. Support for postscript graphics returned from Mathematica exists. (David Konerding)

Linear Programming

• lpsolvpy [details] [source]
  An interface to the LGPL'd numerical linear program solver lp_solve. (Michael Pronath)
• optimize [details] [source]
  A module containing optimization algorithms written in pure Python. Currently it contains implementations of the Nelder-Mead simplex algorithm, the Broyden-Fletcher-Goldfarb-Shanno (BFGS) quasi-Newton algorithm, and a line-search conjugate-gradient Newton algorithm for minimizing a function of many variables. (Travis Oliphant)
• pySimplex [details] [source]
  Pysimplex provides some basic symbolic programming tools for constructing, solving and optimizing systems of linear equations and inequalities. It includes an implementation of the classical SIMPLEX linear optimization algorithm as well as a filter for parsing and optimizing linear models encoded using the standard MPS format. (Aaron Watters)
• Simplex [details] [source]
  Simplex minimizes an arbitrary nonlinear function of N variables by the Nedler-Mead Simplex method. (Vivake Gupta)

Matrix/Vector

• matrix [details] [source]
  Yet Another Matrix Module. This one leans more toward the flexible end of the spectrum, sacrificing performance for correctness. For example, it can correctly handle rationals and other strange things being inserted into it. Also implemented: LU[P] decomposition, and a simultaneous linear equation solving capability. Most of the standard matrix ops: transpose, determinant, inverse, etc.. along with some functional-style methods for mapping and iteration. (Sam Rushing)
• SparsePy [details] [source]
  A module that implements a sparse matrix class for Python. The attributes of the class are Numeric arrays and the methods are based on the included toolkits SPARSEKIT2 by Yousef Saad (in FORTRAN) and SuperLU (in C) by Xiaoye Li and Jim Demmel. Note: You need the BLAS library (in LAPACK at netlib or from your vendor) and a FORTRAN compiler to compile this package. (The binary for Linux just needs Python and NumPy). (Travis Oliphant)
• Sparsemodule [details] [source]
  An extension module wrapping the sparse library. It can be used for solving large systems of linear equations. (Neil Schemenauer)
• MatPy [details] [source]
  A Python package for numerical computation and plotting with a MatLab-like interface. It currently consists of wrappers around the Numeric, Gnuplot and SpecialFuncs packages. It provides an alternative interface to NumPy that is somewhat more convenient for matrix and vector computation. Eventually both will be based directly on the same low level routines. We are also looking for the possibility of interface to Octave. (H. Zhu)

Music

• ratio [details] [source]
  For those who are big fans of Just Intonation, one tedious aspect of this is that you end up fondling ratios a lot. The math gets boring after a while, though I do believe you should be able to do the math on your own to get a feel for what it is you're doing. Having said that, I decided I needed some help because I got sick of reducing multiplied ratios. I've written a quick Python module, ratio.py, which handles a lot of the tedium. In particular, building up JI tetrachords and scales based on justly intuned chords or by katapyknosis is pretty simple with this module. (William Annis)

Neural Networks

• bpnn [details] [source]
  A simple back-propagation neural network module. (Neil Schemenauer)

Number Theory

• logic [details] [source]
  A class which provides pure 2, 3 and multi-value (fuzzy) logic. (Mark Summerfield)

Numerics

• numberTheory [details] [source]
  Collection of functions from the book numberTheory. Darrell Gallion.
• FixedPoint [details] [source]
  Fixed decimal precision arithmetic.
• Fraction [details] [source]
  Simple class implemented in pure Python that does fraction arithmetic. (Mike Hostetler)
• GMP [details] [source]
  The GMP module is an extension module that lets you use the GNU Multiprecision Library's large integers from Python. (Andrew Kuchling)
• SILOON [details] [source]
  SILOON (Scripting Interface Languages for Object-Oriented Numerics) gives users the ability to rapidly prototype their scientific codes in a simple yet elegant fashion using the popular scripting languages Python and Perl. While programming in these flexible and dynamic languages, SILOON users maintain the capability of accessing the full power and complexity of C++ and FORTRAN (coming soon) libraries executed on high-performance parallel computers. (SILOON Team)
• surd [details] [source]
  Irrational numbers (surds) as objects.
• yarn [details] [source]
  Yet Another Rational Numbers module.

Other Tools

• Evol [details] [source]
  Evolutions strategies: Powerful global optimisation Basic class for a global optimisation strategie called 'Evolutionsstrategie' by Prof.Schwefel. (Tobias Polzin)
• explore [details] [source]
  Explore Array Data with Gnuplot Interactive Rotating, Zooming of 3D-gnuplot surface plot. (Tobias Polzin)
• emath [details] [source]
  100% Python functions which are based on the famous Numerical Recipes -- polynomial evaluation, zero- finding, integration, FFT's, and vector operations. "They are loosely modelled after Numerical Recipes in C because I needed, at the time, actual source codes which I can examine instead of just wrappers around Fortran libraries like NumPy and Octave. As evident from the documentations, the routines were written with emphasis on clarity rather than on runtime efficiency." (William Park)
• PyClimate [details] [source]
  A Python package designed to accomplish some usual tasks during the analysis of climate variability using Python. It provides functions to perform some simple IO operations, operations with COARDS-compliant netCDF files, EOF analysis, SVD and CCA analysis of coupled data sets, some linear digital filters, kernel based probabilitydensity function estimation and access to DCDFLIB.C library from Python. (Jon Saenz)
• Pythonica [details] [source]
  A simple version of mathematica for python. (Tobias Polzin)
• Quadrature [details] [source]
  A module that allows one to perform Gaussian Quadrature (numerical integration) over a finite interval for arbitrary Python functions. (Travis Oliphant)
• ScientificPython [details] [source]
  A collection of Python modules that are useful for scientific computing. In this collection you will find modules that cover basic geometry (vectors, tensors, transformations, vector and tensor fields), quaternions, automatic derivatives, (linear) interpolation, polynomials, elementary statistics, nonlinear least-squares fits, unit calculations, Fortran-compatible text formatting, 3D visualization via VRML, and two Tk widgets for simple line plots and 3D wireframe models. (Konrad Hinsen)

Parsing Tools

• kwparsing [details] [source]
  kwParser is a parser generator for Python. It transforms an abstract specification of a language grammar (for example the CORBA Interface Definition Language) together with "interpretation functions" that define the semantics of the language into a compiler or translator or interpreter. In the case of CORBA IDL a python program using kwParser could generate stubs and support code (in Python or some other language) to talk to a CORBA interface. (Aaron Watters)

Random Number Generators

• ccrandom [details] [source]
  This module is mostly compatible with the Python's random module, but uses Linux or BSD's /dev/urandom device to generate numbers, thus yielding more random output than the default Python module. (Christopher A. Craig)
• crng [details] [source]
  The Python module crng implements random-number generators (RNGs) based on several different algorithms producing uniform deviates in the open interval (0,1), i.e. exclusive of the end-point values 0 and 1. A few continuous and integer-valued non-uniform deviates are also available. Each RNG algorithm is implemented as a separate Python extension type. The RNG types are independent of each other, but have very similar interfaces. The entire module is implemented as one single C source code file. (Per J. Kraulis)
• MTRand [details] [source]
  Mersenne Twister random number generator. Far longer period and far higher order of equidistribution than any other implemented generators. Fast generation and efficient use of memory. (Darrell Gallion)

Special Functions

• Cephesmodule [details] [source]
  A module patterned after the umath (ufuncs) module that comes with Numerical Python; it makes most of the special functions (like elliptic, and modified Bessel) from the cephes and amos libraries available to python. (Travis Oliphant)

Statistics

• stats [details] [source]
  A collection of statistical functions, ranging from descriptive statistics (mean, median, histograms, variance, skew, kurtosis, etc.) to inferential statistics (t-tests, F-tests, chi-square, etc.). The functions are defined for operation on lists and, if Numeric is installed, also defined for array arguments. REQUIRES pstat.py (v0.3 or later) and io.py (v0.1 or later). (Gary Strangman)

For more information on related numeric packages, see the Vaults of Parnassus or SourceForge.