LogAndSign Class Reference

#include <newmat.h>

Public Member Functions
	LogAndSign ()
	LogAndSign (Real)
void	operator*= (Real)
void	PowEq (int k)
void	ChangeSign ()
Real	LogValue () const
int	Sign () const
Real	Value () const

Private Attributes
Real	log_value
int	sign

Detailed Description

Definition at line 39 of file newmat.h.

Constructor & Destructor Documentation

LogAndSign() [1/2]

LogAndSign::LogAndSign ( )

inline

Definition at line 46 of file newmat.h.

References sign().

{ log_value=0.0; sign=1; }

LogAndSign() [2/2]

LogAndSign::LogAndSign

(

Real

f

)

Definition at line 641 of file newmat8.cpp.

References sign().

{
   if (f == 0.0) { log_value = 0.0; sign = 0; return; }
   else if (f < 0.0) { sign = -1; f = -f; }
   else sign = 1;
   log_value = log(f);
}

Member Function Documentation

ChangeSign()

void LogAndSign::ChangeSign ( )

inline

Definition at line 50 of file newmat.h.

References sign().

Referenced by CroutMatrix::LogDeterminant(), and BandLUMatrix::LogDeterminant().

{ sign = -sign; }

LogValue()

Real LogAndSign::LogValue ( ) const

inline

Definition at line 51 of file newmat.h.

{ return log_value; }

operator*=()

void LogAndSign::operator*=

(

Real

x

)

Definition at line 617 of file newmat8.cpp.

References sign(), and x.

{
   if (x > 0.0) { log_value += log(x); }
   else if (x < 0.0) { log_value += log(-x); sign = -sign; }
   else sign = 0;
}

PowEq()

void LogAndSign::PowEq

(

int

k

)

Definition at line 624 of file newmat8.cpp.

References sign().

Referenced by IdentityMatrix::LogDeterminant().

{
   if (sign)
   {
      log_value *= k;
      if ( (k & 1) == 0 ) sign = 1;
   }
}

Sign()

int LogAndSign::Sign ( ) const

inline

Definition at line 52 of file newmat.h.

References sign().

{ return sign; }

Value()

Real LogAndSign::Value

(

)

const

Definition at line 633 of file newmat8.cpp.

References sign().

Referenced by BaseMatrix::Determinant().

{
   Tracer et("LogAndSign::Value");
   if (log_value >= FloatingPointPrecision::LnMaximum())
      Throw(OverflowException("Overflow in exponential"));
   return sign * exp(log_value);
}

Member Data Documentation

log_value

Real LogAndSign::log_value

private

Definition at line 43 of file newmat.h.

sign

int LogAndSign::sign

private

Definition at line 44 of file newmat.h.

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

• newmat.h
• newmat8.cpp