Isis 3 Developer Reference
Isis::Basis1VariableFunction Class Referenceabstract

Time based linear equation class. More...

#include <Basis1VariableFunction.h>

Inheritance diagram for Isis::Basis1VariableFunction:
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Collaboration diagram for Isis::Basis1VariableFunction:
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Public Member Functions

 Basis1VariableFunction (const QString &name, int numCoefs)
 Creates a Basis Function with a single variable. More...
 
virtual ~Basis1VariableFunction ()
 Destroys the Basis1VariableFunction object. More...
 
virtual double DerivativeVar (const double value)=0
 This will take the Derivative with respect to the variable and evaluate at given value. More...
 
virtual double DerivativeCoef (const double value, const int coefIndex)=0
 Evaluate the derivative defined by the given coefficients with respect to the coefficient at the given index, at the current value. More...
 
void SetCoefficients (const std::vector< double > &coefs)
 Set the coefficients for the equation. More...
 
double Evaluate (const std::vector< double > &vars)
 Compute the equation using the input variables. More...
 
double Evaluate (const double &var)
 Compute the equation using the input variable. More...
 
virtual void Expand (const std::vector< double > &vars)
 This is the function you should replace depending on your needs. More...
 
int Coefficients () const
 Returns the number of coefficients for the equation. More...
 
int Variables () const
 Returns the number of variables in the equation. More...
 
QString Name () const
 Returns the name of the equation. More...
 
double Term (int c) const
 Returns the cth term. More...
 
double Coefficient (int i) const
 Returns the ith coefficient. More...
 

Protected Attributes

QString p_name
 The name of the equation. Call it by using Name() More...
 
int p_numVars
 The number of variables in the equation. Call it by using Variables() More...
 
int p_numCoefs
 The number of coefficients in the equation. More...
 
std::vector< double > p_coefs
 A vector of the coefficients in the equation. More...
 
std::vector< double > p_terms
 A vector of the terms in the equation. More...
 

Detailed Description

Time based linear equation class.

This is a class for generating a general one-variable equation for the Isis least squares fitting algorithm (IsisLSQ). It allows the programmer to set up equations in the form of:

\[ x = C1*T1 + C2*T2 + ... + CN*TN; \]

where C1-CN are coefficients and T1-TN are terms with a single variable. For example,

\[ x = C1 + C2*t + C3*t**2 \]

Author
2004-06-24 Jeff Anderson

Constructor & Destructor Documentation

◆ Basis1VariableFunction()

Isis::Basis1VariableFunction::Basis1VariableFunction ( const QString &  name,
int  numCoefs 
)

Creates a Basis Function with a single variable.

Parameters
nameName of the Basis1VariableFunction. For example, "affine".
numCoefsNumber of coefficients in the equation. For example:

\[ x = C1 + C2 * x + C3 * x**2 \]

has three coefficients: C1, C2 & C3.

◆ ~Basis1VariableFunction()

virtual Isis::Basis1VariableFunction::~Basis1VariableFunction ( )
inlinevirtual

Destroys the Basis1VariableFunction object.

Member Function Documentation

◆ Coefficient()

double Isis::BasisFunction::Coefficient ( int  i) const
inlineinherited

◆ Coefficients()

int Isis::BasisFunction::Coefficients ( ) const
inlineinherited

Returns the number of coefficients for the equation.

Returns
The number of coefficients.

References Isis::BasisFunction::p_numCoefs.

Referenced by Isis::PolynomialUnivariate::DerivativeCoef(), Isis::PolynomialUnivariate::DerivativeVar(), Isis::SpicePosition::SetPolynomial(), and Isis::SpiceRotation::SetPolynomial().

◆ DerivativeCoef()

virtual double Isis::Basis1VariableFunction::DerivativeCoef ( const double  value,
const int  coefIndex 
)
pure virtual

Evaluate the derivative defined by the given coefficients with respect to the coefficient at the given index, at the current value.

Parameters
[in]value(const double) value at which to evaluate derivative
[in]coefIndex(const int) The index of the coefficient to differentiate with respect to
Returns
(double) The derivative evaluated at given value

Implemented in Isis::PolynomialUnivariate.

◆ DerivativeVar()

virtual double Isis::Basis1VariableFunction::DerivativeVar ( const double  value)
pure virtual

This will take the Derivative with respect to the variable and evaluate at given value.

Parameters
[in]value(const double) value at which to evaluate derivative
Returns
(double) The derivative evaluated at given value

Implemented in Isis::PolynomialUnivariate.

◆ Evaluate() [1/2]

double Isis::BasisFunction::Evaluate ( const std::vector< double > &  vars)
inherited

Compute the equation using the input variables.

Parameters
varsA vector of double values to use for the equation. After setting the coefficients, this can be invoked many times to compute output values given input values.
Returns
The output value.

References _FILEINFO_, Isis::BasisFunction::Expand(), Isis::BasisFunction::p_coefs, Isis::BasisFunction::p_numCoefs, Isis::BasisFunction::p_numVars, Isis::BasisFunction::p_terms, Isis::IException::Programmer, and Isis::toString().

Referenced by Isis::BasisFunction::Evaluate(), Isis::LeastSquares::Evaluate(), Isis::SpiceRotation::EvaluatePolyFunction(), Isis::SpicePosition::LoadHermiteCache(), Isis::SpicePosition::SetEphemerisTimePolyFunction(), and Isis::SpiceRotation::setEphemerisTimePolyFunction().

◆ Evaluate() [2/2]

double Isis::BasisFunction::Evaluate ( const double &  var)
inherited

Compute the equation using the input variable.

Parameters
varA single double value to use for the equation.
Returns
The output double value resulting from the equation.

References Isis::BasisFunction::Evaluate().

◆ Expand()

void Isis::BasisFunction::Expand ( const std::vector< double > &  vars)
virtualinherited

This is the function you should replace depending on your needs.

It will expand the variables into the terms of the equation. For example,

\[ x = C1 + C2*y + C3*z + C4*y*z \]

must be expanded into the p_terms vector as (1.0, y, z, y*z). Note that the term expansion is not limited, you can use cos, sin, sqrt, abs, etc. This virtual method is automatically invoked by the Evaluate method. We provide a default expansion of p_terms = vars, just a linear combination of the variables.

Parameters
varsA vector of double values to use for the expansion.

Reimplemented in Isis::PolynomialUnivariate, and Isis::PolynomialBivariate.

References Isis::BasisFunction::p_terms.

Referenced by Isis::BasisFunction::Evaluate().

◆ Name()

QString Isis::BasisFunction::Name ( ) const
inlineinherited

Returns the name of the equation.

Returns
The name of the equation.

References Isis::BasisFunction::p_name.

Referenced by Isis::LeastSquares::AddKnown().

◆ SetCoefficients()

◆ Term()

double Isis::BasisFunction::Term ( int  c) const
inlineinherited

Returns the cth term.

This is only valid after a Evalute/Expand has been invoked. It represents the expansion of the variables into the ith term. For example,

\[ x = C1 + C2*x + C3*y + C4*x*y \]

would return x*y for the 3rd term (zero-based)

Parameters
cThe index for the desired coefficient.
Returns
The cth term.

References Isis::BasisFunction::p_terms.

◆ Variables()

int Isis::BasisFunction::Variables ( ) const
inlineinherited

Returns the number of variables in the equation.

Returns
The number of variables.

References Isis::BasisFunction::p_numVars.

Referenced by Isis::LeastSquares::AddKnown().

Member Data Documentation

◆ p_coefs

std::vector<double> Isis::BasisFunction::p_coefs
protectedinherited

A vector of the coefficients in the equation.

Call it by using Coefficient()

Referenced by Isis::BasisFunction::Coefficient(), Isis::BasisFunction::Evaluate(), and Isis::BasisFunction::SetCoefficients().

◆ p_name

QString Isis::BasisFunction::p_name
protectedinherited

The name of the equation. Call it by using Name()

Referenced by Isis::BasisFunction::BasisFunction(), and Isis::BasisFunction::Name().

◆ p_numCoefs

int Isis::BasisFunction::p_numCoefs
protectedinherited

◆ p_numVars

int Isis::BasisFunction::p_numVars
protectedinherited

The number of variables in the equation. Call it by using Variables()

Referenced by Isis::BasisFunction::BasisFunction(), Isis::BasisFunction::Evaluate(), and Isis::BasisFunction::Variables().

◆ p_terms

std::vector<double> Isis::BasisFunction::p_terms
protectedinherited

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