permutationfunc Class Reference

Store a list of permutation functions and calculate the binary operator * on these states. More...

#include <permutationfunc.h>

Collaboration diagram for permutationfunc:

List of all members.

Public Member Functions
	permutationfunc (uintc *fop_, uintc N_, uintc dim_)
	Initialize the class with the matrix of functions, the number of functions and the permutations dimension.
uintc *	fi (uintc i) const
	Return the function.
void	ik (uint *x, uintc i, uintc k) const
	Apply binary functions i(k(0,1,.
uintc	ik (bool &found, uintc i, uintc k) const
	Apply binary functions i(k(0,1,.
uintc	inverse (bool &found, uintc *x) const
	Given a permutation find the index if it exists.
void	writeBinaryOperator (bool &result, uint *mat) const
	Write the operator to matrix mat which is assumed to be N by N in length.
Public Attributes
uintc *	fop
	A pointer to the matrix of size N by dim.
uintc	N
	The number of functions.
uintc	dim
	The dimension of the permutation.

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Detailed Description

Store a list of permutation functions and calculate the binary operator * on these states.

General support for permutations so looking at the classes interface does not help much.

This class was written was to calculate the states given the operators as permutations.

Example

  cout << "Test if flipping a triange and rotating it form a group." << endl;

  uint fop[] = 
  {
    0,1,2,
    1,2,0,
    2,0,1,
    0,2,1,
    2,1,0,
    1,0,2
  };
  permutationfunc pf(fop,6,3);

  cout << "Generate the binary table" << endl;

  uint mat[6*6];
  bool result;
  pf.writeBinaryOperator(result,mat);
  if (result==false)
  {
    cout << "Failed to form a binary operator." << endl;
    return;
  }

  binopproperties gt(mat,6);
  cout << "isGroup()=" << gt.isGroup() << endl;

Definition at line 46 of file permutationfunc.h.

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Constructor & Destructor Documentation

permutationfunc::permutationfunc	(	uintc *	fop_,
		uintc	N_,
		uintc	dim_
	)			[inline]

Initialize the class with the matrix of functions, the number of functions and the permutations dimension.

Definition at line 53 of file permutationfunc.h.

    : fop(fop_), N(N_), dim(dim_) {}

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Member Function Documentation

uintc* permutationfunc::fi

(

uintc

i

)

const [inline]

Return the function.

ie the i'th row.

Definition at line 67 of file permutationfunc.h.

References dim, and fop.

    { return fop + dim*i; }

uintc permutationfunc::ik	(	bool &	found,
		uintc	i,
		uintc	k
	)			const

Apply binary functions i(k(0,1,.

.,dim-1) and return the result as a state.

Definition at line 40 of file permutationfunc.cpp.

References dim, ik(), and inverse().

{
  uint x[dim];
  ik(x,i,k);

  return inverse(found,x);
}

void permutationfunc::ik	(	uint *	x,
		uintc	i,
		uintc	k
	)			const

Apply binary functions i(k(0,1,.

.,dim-1) and store in x.

Definition at line 32 of file permutationfunc.cpp.

References dim, fop, and N.

Referenced by ik().

{
  assert(i<N);
  assert(k<N);
  for (uint w=0; w<dim; ++w)
    x[w] = fop[ i*dim + fop[ k*dim + w ] ];
}

uintc permutationfunc::inverse	(	bool &	found,
		uintc *	x
	)			const

Given a permutation find the index if it exists.

Definition at line 8 of file permutationfunc.cpp.

References dim, fop, and N.

Referenced by ik(), and binoppropertiestest::test03().

{
  for (uint i=0; i<N; ++i)
  {
    found=true;
    for (uint k=0; k<dim; ++k)
    {
      if (x[k]!=fop[i*dim+k])
      {
        found=false;
        k=dim;
      }
    }
    
    if (found==false)
      continue;

    return i;
  }

  return 0;
}

void permutationfunc::writeBinaryOperator	(	bool &	result,
		uint *	mat
	)			const

Write the operator to matrix mat which is assumed to be N by N in length.

Definition at line 50 of file permutationfunc.cpp.

Referenced by binoppropertiestest::test05().

{
  result=true;
  bool found;
  for (uint i=0; i<N; ++i)
    for (uint k=0; k<N; ++k)
    {
      mat[i*N+k] = ik(found,i,k);
      result &= found;
    }
}

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Member Data Documentation

uintc permutationfunc::dim

The dimension of the permutation.

Definition at line 64 of file permutationfunc.h.

Referenced by fi(), ik(), and inverse().

uintc* permutationfunc::fop

A pointer to the matrix of size N by dim.

Definition at line 60 of file permutationfunc.h.

Referenced by fi(), ik(), and inverse().

uintc permutationfunc::N

The number of functions.

Definition at line 62 of file permutationfunc.h.

Referenced by ik(), and inverse().

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The documentation for this class was generated from the following files:

• mathlib/permutationfunc.h
• mathlib/permutationfunc.cpp