interp1.hpp

 
#ifndef QLIBS_INTERP1
#define QLIBS_INTERP1
 
#include <include/qlibs_types.hpp>
 
namespace qlibs {
    enum interp1Method {
        INTERP1_NEXT = 0,               
        INTERP1_PREVIOUS,               
        INTERP1_NEAREST,                
        INTERP1_LINEAR,                 
        INTERP1_SINE,                   
        INTERP1_CUBIC,                  
        INTERP1_HERMITE,                
        INTERP1_SPLINE,                 
        INTERP1_CONSTRAINED_SPLINE,     
        INTERP1_MAX,
    };
 
    class interp1 {
        private:
            using interp1Fcn_t = real_t (*)( const real_t x,
                                             const real_t * const tx,
                                             const real_t * const ty,
                                             const size_t tableSize );
            const real_t *xData{ nullptr };
            const real_t *yData{ nullptr };
            size_t dataSize{ 0U };
            interp1Fcn_t method{ &linear };
            static real_t slope( const real_t * const tx,
                                 const real_t * const ty,
                                 const size_t i );
            static real_t firstDerivate( const real_t * const tx,
                                         const real_t * const ty,
                                         const size_t n,
                                         const size_t i );
            static real_t leftSecondDerivate( const real_t * const tx,
                                              const real_t * const ty,
                                              const size_t n,
                                              const size_t i );
            static real_t rightSecondDerivate( const real_t * const tx,
                                               const real_t * const ty,
                                               const size_t n,
                                               const size_t i );
            static real_t next( const real_t x,
                                const real_t * const tx,
                                const real_t * const ty,
                                const size_t tableSize );
            static real_t previous( const real_t x,
                                    const real_t * const tx,
                                    const real_t * const ty,
                                    const size_t tableSize );
            static real_t nearest( const real_t x,
                                   const real_t * const tx,
                                   const real_t * const ty,
                                   const size_t tableSize );
            static real_t linear( const real_t x,
                                  const real_t * const tx,
                                  const real_t * const ty,
                                  const size_t tableSize );
            static real_t sine( const real_t x,
                                const real_t * const tx,
                                const real_t * const ty,
                                const size_t tableSize );
            static real_t cubic( const real_t x,
                                 const real_t * const tx,
                                 const real_t * const ty,
                                 const size_t tableSize );
            static real_t hermite( const real_t x,
                                   const real_t * const tx,
                                   const real_t * const ty,
                                   const size_t tableSize );
            static real_t spline( const real_t x,
                                  const real_t * const tx,
                                  const real_t * const ty,
                                  const size_t tableSize );
            static real_t cSpline( const real_t x,
                                   const real_t * const tx,
                                   const real_t * const ty,
                                   const size_t tableSize );
        public:
            virtual ~interp1() {}
            interp1( const real_t * const xTable,
                     const real_t * const yTable,
                     const size_t sizeTable ) : xData( xTable ), yData( yTable ), dataSize( sizeTable ) {}
 
            template <size_t sizeTable>
            interp1( real_t (&xTable)[ sizeTable ],
                     real_t (&yTable)[ sizeTable ] ) : interp1( xTable, yTable, sizeTable ) {}
 
            bool setData( const real_t * const xTable,
                          const real_t * const yTable,
                          const size_t sizeTable )
            {
                bool retValue = false;
 
                if ( ( nullptr != xTable ) && ( nullptr != yTable ) && ( sizeTable >= 4U ) ) {
                    xData = xTable;
                    yData = yTable;
                    dataSize = sizeTable;
                    retValue = true;
                }
                return retValue;
            }
 
            template <size_t sizeTable>
            bool setData( real_t (&xTable)[ sizeTable ],
                          real_t (&yTable)[ sizeTable ] )
            {
                return setData( xTable, yTable, sizeTable );
            }
 
            bool setMethod( const interp1Method m ) noexcept;
            template <typename T>
 
            inline real_t get( const T x ) noexcept
            {
                return method( static_cast<real_t>( x ), xData, yData, dataSize );
            }
    };
 
}
 
 
#endif /*QLIBS_INTERP1*/