Python/linear_algebra

Linear algebra library for Python

This module contains some useful classes and functions for dealing with linear algebra in python 2.

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Overview

class Vector

• • This class represents a vector of arbitray size and operations on it.

  Overview about the methods:

  • constructor(components : list) : init the vector
  • set(components : list) : changes the vector components.
  • __str__() : toString method
  • component(i : int): gets the i-th component (start by 0)
  • __len__() : gets the size / length of the vector (number of components)
  • euclidLength() : returns the eulidean length of the vector.
  • operator + : vector addition
  • operator - : vector subtraction
  • operator * : scalar multiplication and dot product
  • copy() : copies this vector and returns it.
  • changeComponent(pos,value) : changes the specified component.

• function zeroVector(dimension)

  • returns a zero vector of 'dimension'

• function unitBasisVector(dimension,pos)

  • returns a unit basis vector with a One at index 'pos' (indexing at 0)

• function axpy(scalar,vector1,vector2)

  • computes the axpy operation

• function randomVector(N,a,b)

  • returns a random vector of size N, with random integer components between 'a' and 'b'.

class Matrix

• • This class represents a matrix of arbitrary size and operations on it.

  Overview about the methods:

  • __str__() : returns a string representation
  • operator * : implements the matrix vector multiplication
    implements the matrix-scalar multiplication.
  • changeComponent(x,y,value) : changes the specified component.
  • component(x,y) : returns the specified component.
  • width() : returns the width of the matrix
  • height() : returns the height of the matrix
  • operator + : implements the matrix-addition.
  • operator - _ implements the matrix-subtraction

• function squareZeroMatrix(N)

  • returns a square zero-matrix of dimension NxN

• function randomMatrix(W,H,a,b)

  • returns a random matrix WxH with integer components between 'a' and 'b'

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Documentation

The module is well documented. You can use the python in-built help(...) function.
For instance: help(Vector) gives you all information about the Vector-class.
Or help(unitBasisVector) gives you all information you needed about the
global function unitBasisVector(...). If you need informations about a certain
method you type help(CLASSNAME.METHODNAME).

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Usage

You will find the module in the src directory its called lib.py. You need to
import this module in your project. Alternative you can also use the file lib.pyc in python-bytecode.

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Tests

In the src directory you also find the test-suite, its called tests.py.
The test-suite uses the built-in python-test-framework unittest.