LatNet Builder Manual
2.0.1-11
Software Package for Constructing Highly Uniform Point Sets
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This class implements theoretical bounds on the values of \(P_{\alpha}\) for a lattice (see class Palpha
).
More...
#include <NormaPalpha.h>
Inherits LatticeTester::Normalizer< RedDbl >.
Public Member Functions | |
NormaPalpha (const Int &m, int alpha, int s, NormType norm=L2NORM) | |
Constructor for the bounds \(B_{\alpha}(s)\) obtained for lattices, in all dimensions \(\le s\), where \(\alpha= {}\)alpha . More... | |
double | calcBound (int alpha, int s) |
Computes and returns the bound \(B_{\alpha}(s)\) given in [33] (p. More... | |
void | init (int alpha) |
Initializes the bounds for the Palpha normalization. | |
int | getAlpha () const |
Returns the value of \(\alpha\). | |
Public Member Functions inherited from LatticeTester::Normalizer< RedDbl > | |
Normalizer (RedDbl &logDensity, int t, std::string Name, NormType norm=L2NORM, double beta=1) | |
Constructor for the bounds. More... | |
Normalizer (int t, std::string Name, NormType norm=L2NORM, double beta=1) | |
Constructor only used by the NormaPalpha class. More... | |
virtual | ~Normalizer () |
Destructor. | |
virtual void | init (RedDbl &logDensity, double beta) |
Initializes the bounds on the length of the shortest vector. More... | |
std::string | ToString () const |
Returns this object as a string. | |
NormType | getNorm () const |
Returns the norm associated with this object. | |
void | setLogDensity (RedDbl logDensity) |
Sets the log-density associated with this object to logDensity . | |
RedDbl | getLogDensity () const |
Returns the logDensity associated with this object. | |
void | setNorm (NormType norm) |
Sets the norm associated with this object to norm . | |
int | getDim () const |
Returns the maximal dimension for this object. | |
double | getPreComputedBound (int j) const |
Returns the bound on the length of the shortest nonzero vector in dimension \(j\) as computed in Normalizer::init. | |
double | getBound (int j) const |
Calculates and returns the bound on the length of the shortest nonzero vector in dimension \(j\). | |
virtual double | getGamma (int j) const |
Returns the value of the lattice constant \(\gamma_j\) in dimension \(j\). More... | |
Additional Inherited Members | |
Static Public Attributes inherited from LatticeTester::Normalizer< RedDbl > | |
static const int | MAX_DIM = 48 |
Protected Attributes inherited from LatticeTester::Normalizer< RedDbl > | |
std::string | m_name |
Name of the normalizer. | |
NormType | m_norm |
Norm associated with this object. | |
RedDbl | m_logDensity |
log of the density, ie log of the number of points of the lattice per unit of volume. | |
int | m_maxDim |
Only elements 1 to m_maxDim (inclusive) of arrays are defined. | |
double | m_beta |
Beta factor. | |
double * | m_bounds |
Contains the bounds on the length of the shortest nonzero vector in the lattice in each dimension. | |
This class implements theoretical bounds on the values of \(P_{\alpha}\) for a lattice (see class Palpha
).
LatticeTester::NormaPalpha< Int, RedDbl >::NormaPalpha | ( | const Int & | m, |
int | alpha, | ||
int | s, | ||
NormType | norm = L2NORM |
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) |
Constructor for the bounds \(B_{\alpha}(s)\) obtained for lattices, in all dimensions \(\le s\), where \(\alpha= {}\)alpha
.
The lattices have rank \(1\), with \(m\) points per unit volume. Restriction: \(2 \le s \le48\), \(\alpha\ge2\), and \(m\) prime.
double LatticeTester::NormaPalpha< Int, RedDbl >::calcBound | ( | int | alpha, |
int | s | ||
) |
Computes and returns the bound \(B_{\alpha}(s)\) given in [33] (p.
83, Theorem 4.4). Given \(s > 1\), \(\alpha> 1\), \(m\) prime, and \(m > e^{\alpha s/(\alpha-1)}\), then there exists an integer vector \(\mathbf{a} \in\mathbb Z^s\) such that
\[ P_{\alpha}(s, \mathbf{a}) \le B_{\alpha}(s) = \frac{e}{s}^{\alpha s} \frac{(2\ln m + s)^{\alpha s}}{m^{\alpha}}. \]
If the conditions for the existence of the bound are not satisfied, the function returns \(-1\).
References NTL::conv(), and LatticeTester::IntFactor< Int >::isPrime().