MHATableLookup::linear_table_t Class Reference

Class for interpolation with equidistant x values. More...

Inheritance diagram for MHATableLookup::linear_table_t:

Public Member Functions
	linear_table_t (void)
	contructor creates an empty linear_table_t object. More...
mha_real_t	lookup (mha_real_t x) const
	look up the y value that is stored for the mesh point where x is lower than or equal to the x value given here. More...
mha_real_t	interp (mha_real_t x) const
	interpolate y value for the given x value. More...
	~linear_table_t (void)
	destructor More...
void	set_xmin (mha_real_t xmin)
	set the x value for the first mesh point. More...
void	add_entry (mha_real_t y)
	set the y value for the next mesh point. More...
void	set_xmax (mha_real_t xmax)
	this sets the x value for a past-the-end, not added mesh point. More...
void	prepare (void)
	prepare computes the x distance of the mesh points based on the values given to set_xmin, set_xmax, and the number of times that add_entry was called. More...
void	clear (void)
	clear resets the state of this object to the state directly after construction. More...
Public Member Functions inherited from MHATableLookup::table_t
	table_t (void)
virtual	~table_t (void)

Protected Attributes
mha_real_t *	vy
unsigned int	len

Private Attributes
vector< mha_real_t >	vec_y
mha_real_t	xmin
mha_real_t	xmax
mha_real_t	scalefac

Additional Inherited Members

Detailed Description

Class for interpolation with equidistant x values.

This class can be used for linear interpolation tasks where the mesh points are known for equidistant x values.

Before the class can be used for interpolation, it has to be filled with the y values for the mesh points, the x range has to be specified, and when all values are given, the prepare method has to be called so that the object can determine the distance between x values from the range and the number of mesh points given.

Only after prepare has returned, the object may be used for interpolation.

Constructor & Destructor Documentation

linear_table_t()

linear_table_t::linear_table_t

(

void

)

contructor creates an empty linear_table_t object.

add_entry, set_xmin, set_xmax and prepare methods have to be called before the object can be used to lookup and interpolate values.

~linear_table_t()

linear_table_t::~linear_table_t

(

void

)

destructor

Member Function Documentation

lookup()

mha_real_t linear_table_t::lookup ( mha_real_t  x ) const

virtual

look up the y value that is stored for the mesh point where x is lower than or equal to the x value given here.

This method does not extrapolate, so for x < xmin, the y value for xmin is returned. For all x greater than the x of the last mesh point, the y value of the last mesh point is returned.

Precondition

prepare must have been called before lookup may be called.

Implements MHATableLookup::table_t.

interp()

mha_real_t linear_table_t::interp ( mha_real_t  x ) const

virtual

interpolate y value for the given x value.

The y values for the neighbouring mesh points are looked up and linearly interpolated. For x values outside the range of mesh points, the y value is extrapolated from the nearest two mesh points.

Precondition

prepare must have been called before interp may be called.

Implements MHATableLookup::table_t.

set_xmin()

void linear_table_t::set_xmin

(

mha_real_t

xmin

)

set the x value for the first mesh point.

Must be called before prepare can be called.

add_entry()

void linear_table_t::add_entry

(

mha_real_t

y

)

set the y value for the next mesh point.

Must be called at least twice before prepare can be called.

set_xmax()

void linear_table_t::set_xmax

(

mha_real_t

xmax

)

this sets the x value for a past-the-end, not added mesh point.

Example:

t.set_xmin(100);
t.add_entry(0); // mesh point {100,0}
t.add_entry(1); // mesh point {110,1}
// the next mesh point would be at x=120, but we do not add this
t.set_xmax(120); // the x where the next mesh point would be
t.prepare();

now, t.interp(100) == 0; t.interp(110) == 1; t.interp(105) == 0.5;

prepare()

void linear_table_t::prepare

(

void

)

prepare computes the x distance of the mesh points based on the values given to set_xmin, set_xmax, and the number of times that add_entry was called.

Precondition

set_xmin, set_xmax, add_entry functions must have been called before calling prepare, add_entry must have been called at least twice.

Only after this method has been called, interp or lookup may be called.

clear()

void linear_table_t::clear ( void  )

virtual

clear resets the state of this object to the state directly after construction.

mesh entries and x range are deleted.

interp and lookup may not be called after this function has been called unless prepare and before that its precondition methods are called again.

Implements MHATableLookup::table_t.

Member Data Documentation

vy

mha_real_t* MHATableLookup::linear_table_t::vy

protected

len

unsigned int MHATableLookup::linear_table_t::len

protected

vec_y

vector<mha_real_t> MHATableLookup::linear_table_t::vec_y

private

xmin

mha_real_t MHATableLookup::linear_table_t::xmin

private

xmax

mha_real_t MHATableLookup::linear_table_t::xmax

private

scalefac

mha_real_t MHATableLookup::linear_table_t::scalefac

private

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

• mha_tablelookup.hh
• mha_tablelookup.cpp