imath::CLinearInterpolator Class Reference

Implementation of a linear interpolator for piecewise linear function approximation. More...

#include <CLinearInterpolator.h>

Inheritance diagram for imath::CLinearInterpolator:

Public Member Functions
	CLinearInterpolator ()
	CLinearInterpolator (double *positions, double *values, int nodesCount, bool isExtrapolationEnabled=false)
void	SetNodes (double *positions, double *values, int nodesCount)
virtual bool	InitFromFunction (const ISampledFunction &function) override
	Initialize interpolator based on a sample function.
virtual bool	GetValueAt (const double &argument, double &result) const override
virtual double	GetValueAt (const double &argument) const override
Public Member Functions inherited from imath::TIMathFunction< Argument, Result >
virtual bool	GetValueAt (const Argument &argument, Result &result) const =0
	Get function value for specified argument value.
virtual Result	GetValueAt (const Argument &argument) const =0
	Get function value for specified argument value.
Public Member Functions inherited from istd::IPolymorphic
virtual	~IPolymorphic ()

Additional Inherited Members
Public Types inherited from imath::TIMathFunction< Argument, Result >
typedef Argument	ArgumentType
typedef Result	ResultType

Detailed Description

Implementation of a linear interpolator for piecewise linear function approximation.

Purpose

CLinearInterpolator provides simple and efficient piecewise linear interpolation through a set of data points. It creates straight line segments between consecutive points, offering exact reproduction of linear functions and predictable behavior for all input data. Optional extrapolation extends the function beyond the defined domain using the slopes of the first and last segments.

Characteristics

• Simplicity: Straightforward, predictable behavior
• Efficiency: Fast evaluation, minimal computation
• Exactness: Passes exactly through all data points
• Continuity: C0 continuous (continuous value but not derivative)
• No oscillation: Cannot produce spurious oscillations between points

Usage Examples

// Create interpolator with extrapolation disabled (default)
double positions[] = {0.0, 1.0, 2.0, 3.0};
double values[] = {0.0, 2.0, 1.5, 3.0};
imath::CLinearInterpolator interp1(positions, values, 4, false);
 
// Query inside domain
double result;
if (interp1.GetValueAt(1.5, result)) {
       // result ~ 1.75 (linear interpolation between 2.0 and 1.5)
}
 
// Query outside domain (no extrapolation)
double value1 = interp1.GetValueAt(-1.0);  // Returns 0.0 (first value)
double value2 = interp1.GetValueAt(5.0);   // Returns 3.0 (last value)
 
// Create interpolator with extrapolation enabled
imath::CLinearInterpolator interp2(positions, values, 4, true);
double value3 = interp2.GetValueAt(-1.0);  // Extrapolates using first segment slope
double value4 = interp2.GetValueAt(5.0);   // Extrapolates using last segment slope
 
// Initialize from ISampledFunction
// interp1.InitFromFunction(sampledFunction);

When to Use

Use linear interpolation when:

• Data has sharp transitions or discontinuities in derivatives
• Simplicity and predictability are important
• Performance is critical (fastest interpolation method)
• You need exact reproduction at data points
• Data represents piecewise linear relationships

Consider other methods when:

• You need smooth curves (use CAkimaInterpolator or splines)
• Data represents smooth continuous phenomena
• Visual quality matters more than simplicity

See also

imath::CAkimaInterpolator, imath::ISampledFunctionInterpolator

Definition at line 76 of file CLinearInterpolator.h.

Constructor & Destructor Documentation

CLinearInterpolator() [1/2]

imath::CLinearInterpolator::CLinearInterpolator

(

)

CLinearInterpolator() [2/2]

imath::CLinearInterpolator::CLinearInterpolator	(	double *	positions,
		double *	values,
		int	nodesCount,
		bool	isExtrapolationEnabled = false
	)

Parameters

isExtrapolationEnabled

If enabled, the values will be extrapolatied also outside of defined domain, otherwise returned value for argument outside[positionMin, positionMax] is the last value.

Member Function Documentation

GetValueAt() [1/2]

virtual double imath::CLinearInterpolator::GetValueAt ( const double &  argument ) const

overridevirtual

GetValueAt() [2/2]

virtual bool imath::CLinearInterpolator::GetValueAt ( const double &  argument, double &  result  ) const

overridevirtual

InitFromFunction()

virtual bool imath::CLinearInterpolator::InitFromFunction ( const ISampledFunction &  function )

overridevirtual

Initialize interpolator based on a sample function.

Implements imath::ISampledFunctionInterpolator.

SetNodes()

void imath::CLinearInterpolator::SetNodes	(	double *	positions,
		double *	values,
		int	nodesCount
	)

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

• Acf/Include/imath/CLinearInterpolator.h