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ktechlab/src/electronics/simulation/matrix.h

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/***************************************************************************
* Copyright (C) 2003-2004 by David Saxton *
* david@bluehaze.org *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
***************************************************************************/
#ifndef MATRIX_H
#define MATRIX_H
#include "vec.h"
#include <vector>
class Map;
typedef std::vector<std::vector<uint> > ETMap;
/**
@short Handles row-wise permutation of matrixes
*/
class Map
{
public:
enum e_type
{
et_none = 0x0, // Default value, none
et_constant = 0x1, // Never changes value in lifetime of matrix
et_stable = 0x2, // Value changes occasionally, e.g. user changing resistance value
et_variable = 0x3, // Rate of changing is unknown, probably average - e.g. logic
et_unstable = 0x4, // Value changes practically every call of performLU
et_big = 0x8 // Ignore this :-) It is used to OR with one of the others, but it should only ever be accessed by the class
};
Map( const uint size );
~Map();
void setUse( const uint i, const uint j, Map::e_type type, bool big );
/**
* Generates an optimal permutation, returned in the given array
*/
void createMap( int *map );
/**
* Resets the info to a blank pattern
*/
void reset();
protected:
/**
* Compares two "types", returning true if t1 >= t2, else false
*/
bool typeCmp( const uint t1, const uint t2 );
private:
ETMap *m_map;
uint m_size;
};
/**
This class performs matrix storage, lu decomposition, forward and backward
substitution, and a few other useful operations. Steps in using class:
(1) Create an instance of this class with the correct size
(2) Define the matrix pattern as neccessary:
(1) Call zero (unnecessary after initial ceration) to reset the pattern
& matrix
(2) Call setUse to set the use of each element in the matrix
(3) Call createMap to generate the row-wise permutation mapping for use
in partial pivoting
(3) Add the values to the matrix
(4) Call performLU, and get the results with fbSub
(5) Repeat 2, 3, 4 or 5 as necessary.
@todo We need to allow createMap to work while the matrix has already been initalised
@short Matrix manipulation class tailored for circuit equations
@author David Saxton
*/
class Matrix
{
public:
/**
* Creates a size x size square matrix m, with all values zero,
* and a right side vector x of size m+n
*/
Matrix( uint n, uint m );
~Matrix();
/**
* Sets all elements to zero
*/
void zero();
/**
* Sets the type of (matrix-) element at the position i, j.
* @param type Describes how often the value changes
* @param big Set this true if the value is likely to be >= 1, else false
*/
void setUse( const uint i, const uint j, Map::e_type type, bool big );
void setUse_b( const uint i, const uint j, Map::e_type type, bool big )
{
setUse( i, j+m_n, type, big );
}
void setUse_c( const uint i, const uint j, Map::e_type type, bool big )
{
setUse( i+m_n, j, type, big );
}
void setUse_d( const uint i, const uint j, Map::e_type type, bool big )
{
setUse( i+m_n, j+m_n, type, big );
}
/**
* Generates the row-wise permutation mapping from the values set by setUse
*/
void createMap();
/**
* Returns true if the matrix is changed since last calling performLU()
* - i.e. if we do need to call performLU again.
*/
inline bool isChanged() const { return max_k < m_size; }
/**
* Performs LU decomposition. Going along the rows,
* the value of the decomposed LU matrix depends only on
* the previous values.
*/
void performLU();
/**
* Applies the right side vector (x) to the decomposed matrix,
* with the solution returned in x.
*/
void fbSub( Vector* x );
/**
* Prints the matrix to stdout
*/
void displayMatrix();
/**
* Prints the LU-decomposed matrix to stdout
*/
void displayLU();
/**
* Sets the element matrix at row i, col j to value x
*/
double& g( uint i, uint j )
{
i = m_inMap[i];
if ( i<max_k ) max_k=i;
if ( j<max_k ) max_k=j;
// I think I need the next line...
if ( max_k>0 ) max_k--;
return (*m_mat)[i][j];
}
double& b( uint i, uint j ) { return g( i, j+m_n ); }
double& c( uint i, uint j ) { return g( i+m_n, j ); }
double& d( uint i, uint j ) { return g( i+m_n, j+m_n ); }
const double g( uint i, uint j ) const { return (*m_mat)[m_inMap[i]][j]; }
const double b( uint i, uint j ) const { return g( i, j+m_n ); }
const double c( uint i, uint j ) const { return g( i+m_n, j ); }
const double d( uint i, uint j ) const { return g( i+m_n, j+m_n ); }
/**
* Returns the value of matrix at row i, col j.
*/
const double m( uint i, uint j ) const
{
return (*m_mat)[m_inMap[i]][j];
}
/**
* Multiplies this matrix by the Vector rhs, and places the result
* in the vector pointed to by result. Will fail if wrong size.
*/
void multiply( Vector *rhs, Vector *result );
/**
* Sets the values of this matrix to that of the given matrix
*/
void operator=( Matrix *const m );
/**
* Adds the values of the given matrix to this matrix
*/
void operator+=( Matrix *const m );
private:
/**
* Swaps around the rows in the (a) the matrix; and (b) the mappings
*/
void swapRows( const uint a, const uint b );
// // Generates m_outMap from m_inMap
// void genOutMap();
uint m_n;
uint m_m;
uint m_size;
uint max_k;
int *m_inMap; // Rowwise permutation mapping from external reference to internal storage
// int *m_outMap; // Opposite of m_inMap
matrix *m_mat;
matrix *m_lu;
double *m_y; // Avoids recreating it lots of times
Map *m_map;
};
/**
This class provides a very simple, lightweight, 2x2 matrix solver.
It's fast and reliable. Set the values for the entries of A and b:
A x = b
call solve() (which returns true if successful - i.e. exactly one solution to the
matrix), and get the values of x with the appropriate functions.
@short 2x2 Matrix
@author David Saxton
*/
class Matrix22
{
public:
Matrix22();
double &a11() { return m_a11; }
double &a12() { return m_a12; }
double &a21() { return m_a21; }
double &a22() { return m_a22; }
double &b1() { return m_b1; }
double &b2() { return m_b2; }
/**
* Solve the matrix. Returns true if successful (i.e. non-singular), else
* false. Get the solution with x1() and x2().
*/
bool solve();
/**
* Resets all entries to zero
*/
void reset();
double x1() const { return m_x1; }
double x2() const { return m_x2; }
private:
double m_a11, m_a12, m_a21, m_a22;
double m_b1, m_b2;
double m_x1, m_x2;
};
#endif