ProbeFunction1D Class Reference

#include <probefunction1d.h>

Collaboration diagram for ProbeFunction1D:

[legend]

List of all members.

Public Member Functions
	ProbeFunction1D ()
void	sampleFunction (Function1D &f, unsigned cmp, double a, double b, unsigned nPoints)
	ProbeFunction1D (Function1D &f, unsigned cmp, double a, double b, unsigned nPoints)
	~ProbeFunction1D ()
void	getMinMaxValues (double c1, double c2, double &min, double &max) const
void	getMaxValues (double c1, double c2, double &max)
void	print ()
Private Types
enum	FunctionBehavour { INCREASING, DECREASING }
Private Member Functions
void	add (double x, double fx)
void	setType (FunctionBehavour beh)
FunctionBehavour	getType (unsigned i) const
unsigned	find (double c) const
Private Attributes
Function1D *	m_f
double	m_a
double	m_b
unsigned	m_cmp
std::vector< double >	m_vX
std::vector< double >	m_vF
std::vector< FunctionBehavour >	m_vType

---

Detailed Description

This function probe a 1D function storing the regions where the value of the function increase or decrease and the stable points. With these information, we can easily find the maximum and minumum values of a function in any interval.

Definition at line 13 of file probefunction1d.h.

---

Member Enumeration Documentation

enum ProbeFunction1D::FunctionBehavour [private]

Enumerator:

INCREASING
DECREASING

Definition at line 21 of file probefunction1d.h.

{INCREASING,DECREASING};

---

Constructor & Destructor Documentation

ProbeFunction1D::ProbeFunction1D

(

)

[inline]

Definition at line 32 of file probefunction1d.h.

{m_f=NULL;m_a=m_b=NAN;}

ProbeFunction1D::ProbeFunction1D	(	Function1D &	f,
		unsigned	cmp,
		double	a,
		double	b,
		unsigned	nPoints
	)

Definition at line 7 of file probefunction1d.cpp.

  :m_f(&f),m_cmp(cmp)
{
  assert(a<b);

  m_a = a;
  m_b = b;
  
  double dx = (b-a)/((double) nPoints);
  double xPrev = a;
  double fxPrev=f(a,m_cmp);

  double x=a+dx;
  double fx=f(x,m_cmp);

  FunctionBehavour currType;

  
  this->add(xPrev,fxPrev);
  if (fxPrev < fx)
    currType = INCREASING;
  else
    currType = DECREASING;
  this->setType(currType);
  
  for (unsigned i=1;i<nPoints;i++)
  {
    fxPrev = fx;
    xPrev = x;
    x+=dx;
    fx = f(x,m_cmp);
    
    if (currType == INCREASING && (fx < fxPrev))
    {
      this->add(xPrev,fxPrev);
      currType=DECREASING;
      this->setType(currType);
    }
    if (currType == DECREASING && (fx > fxPrev))
    {
      this->add(xPrev,fxPrev);
      currType=INCREASING;
      this->setType(currType);
    }
  }
}

ProbeFunction1D::~ProbeFunction1D

(

)

[inline]

Definition at line 36 of file probefunction1d.h.

{}

---

Member Function Documentation

void ProbeFunction1D::add	(	double	x,
		double	fx
	)			[private]

Definition at line 54 of file probefunction1d.cpp.

{
  m_vF.push_back(fx);
  m_vX.push_back(x);
}

unsigned ProbeFunction1D::find

(

double

c

)

const [private]

Given a point in the domain of the function, get the index of the stationary point located imediately left of the the given point. If such smaller point doesnt exist, it return the index 0 belonging to the most left point of the probe domain.

Parameters:

c

The point.

Returns:

Definition at line 167 of file probefunction1d.cpp.

{
  assert(!m_vX.empty());
  if (!((c>=m_a) && (c<=m_b)))
       throw new Exception("ProbeFunction1D::getMinMaxValues value %g not contained in the probe interval [%g,%g]",
                           c,m_a,m_b);
  unsigned i;
  for(i=0;i<m_vX.size();i++)
  {
    if (m_vX[i] > c)
      return i-1;
  }
  return i-1;
}

void ProbeFunction1D::getMaxValues	(	double	c1,
		double	c2,
		double &	max
	)

Definition at line 120 of file probefunction1d.cpp.

{
  assert(c1<=c2);
  assert(c1 >= m_a && c2 <= m_b);
    //  NumericMethods::adjustBounds(c1,m_a,m_b);
    //NumericMethods::adjustBounds(c2,m_a,m_b);

  Function1D &f = *m_f;
  int indexC1 = this->find(c1);
  int indexC2 = this->find(c2);

  if (indexC1 == indexC2)
  {
    if (this->getType(indexC1) == INCREASING)
    {
      max = f(c2,m_cmp);
    }
    else 
    {
      max = f(c1,m_cmp);
    }
  }
  else
  {
    assert(indexC1 < indexC2 && (unsigned) indexC2 < m_vF.size());
    double fx;
    max = f(c1,m_cmp);
    for (int i= indexC1+1;i<=indexC2;i++)
    {
      fx = m_vF[i];
      if (fx > max)
        max = fx;
    }
    fx = f(c2,m_cmp);
    if (fx > max)
      max = fx;
  }
}

void ProbeFunction1D::getMinMaxValues	(	double	c1,
		double	c2,
		double &	min,
		double &	max
	)			const

Get the minimum and maximum value in the interval [c1,c2] of the function passed as parameter in the constructor method.

Parameters:

	c1
	c2

Returns:

Definition at line 72 of file probefunction1d.cpp.

{
  //See if the probe function already got the probe information.
  //Users should always call the sampleFunction method first,
  //Or use the non default constructor 
  assert(m_f);
  assert(c1<=c2);
  //  assert(c1 >= m_a && c2 <= m_b);
  NumericMethods::adjustBounds(c1,m_a,m_b);
  NumericMethods::adjustBounds(c2,m_a,m_b);
  int indexC1 = this->find(c1);
  int indexC2 = this->find(c2);
  Function1D &f = *m_f;
  if (indexC1 == indexC2)
  {
    if (this->getType(indexC1) == INCREASING)
    {
      min = f(c1,m_cmp);
      max = f(c2,m_cmp);
    }
    else 
    {
      min = f(c2,m_cmp);
      max = f(c1,m_cmp);
    }
  }
  else
  {
    assert(indexC1 < indexC2 && (unsigned) indexC2 < m_vF.size());
    double fx;
    min = max = f(c1,m_cmp);
    for (int i= indexC1+1;i<=indexC2;i++)
    {
      fx = m_vF[i];
      if (fx > max)
        max = fx;
      else if (fx < min)
        min = fx;
    }
    fx = f(c2,m_cmp);
    if (fx > max)
      max = fx;
    else if (fx < min)
      min = fx;
  }
}

FunctionBehavour ProbeFunction1D::getType

(

unsigned

i

)

const [inline, private]

Definition at line 27 of file probefunction1d.h.

{assert(i<m_vType.size());return m_vType[i];}

void ProbeFunction1D::print

(

)

Print the gathered information about the function f, passed as argument to the class' constructor.

Returns:

Definition at line 187 of file probefunction1d.cpp.

{
  for (unsigned i=0;i<m_vX.size();i++)
  {
    printf("Point: %g,%g ",m_vX[i],m_vF[i]);
  if (m_vType[i] == INCREASING)
    printf("-- INCREASING --\n");
  if (m_vType[i] == DECREASING)
    printf("-- DECREASING --\n");
  }
  printf("Point: %g,%g\n",m_b,(*m_f)(m_b,m_cmp));
  
}

void ProbeFunction1D::sampleFunction	(	Function1D &	f,
		unsigned	cmp,
		double	a,
		double	b,
		unsigned	nPoints
	)

Definition at line 202 of file probefunction1d.cpp.

{
  m_f=&f;
  m_cmp=cmp;

  assert(a<b);

  m_a = a;
  m_b = b;
  
  double dx = (b-a)/((double) nPoints);
  double xPrev = a;
  double fxPrev=f(a,m_cmp);

  double x=a+dx;
  double fx=f(x,m_cmp);

  FunctionBehavour currType;

  
  this->add(xPrev,fxPrev);
  if (fxPrev < fx)
    currType = INCREASING;
  else
    currType = DECREASING;
  this->setType(currType);
  
  for (unsigned i=1;i<nPoints;i++)
  {
    fxPrev = fx;
    xPrev = x;
    x+=dx;
    fx = f(x,m_cmp);
    
    if (currType == INCREASING && (fx < fxPrev))
    {
      this->add(xPrev,fxPrev);
      currType=DECREASING;
      this->setType(currType);
    }
    if (currType == DECREASING && (fx > fxPrev))
    {
      this->add(xPrev,fxPrev);
      currType=INCREASING;
      this->setType(currType);
    }
  }

}

void ProbeFunction1D::setType

(

FunctionBehavour

beh

)

[private]

Definition at line 60 of file probefunction1d.cpp.

{
  m_vType.push_back(beh);
}

---

Member Data Documentation

double ProbeFunction1D::m_a [private]

Definition at line 17 of file probefunction1d.h.

double ProbeFunction1D::m_b [private]

Definition at line 17 of file probefunction1d.h.

unsigned ProbeFunction1D::m_cmp [private]

Definition at line 18 of file probefunction1d.h.

Function1D* ProbeFunction1D::m_f [private]

Definition at line 16 of file probefunction1d.h.

std::vector<double> ProbeFunction1D::m_vF [private]

Definition at line 20 of file probefunction1d.h.

std::vector<FunctionBehavour> ProbeFunction1D::m_vType [private]

Definition at line 22 of file probefunction1d.h.

std::vector<double> ProbeFunction1D::m_vX [private]

Definition at line 19 of file probefunction1d.h.

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

• probefunction1d.h
• probefunction1d.cpp