Sine.H

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    Copyright (C) 2016-2017 OpenFOAM Foundation
    Copyright (C) 2020-2022 OpenCFD Ltd.
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License
    This file is part of OpenFOAM.
 
    OpenFOAM is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
 
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    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    for more details.
 
    You should have received a copy of the GNU General Public License
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
 
Class
    Foam::Function1Types::Sine
 
Description
    A templated sine function, with support for offset etc.
 
    The wave period can be specified directly
 
        \f[
            a sin(2 \pi (t - t0) / p)) s + l
        \f]
 
    Or it can be specified by the frequency
 
        \f[
            a sin(2 \pi f (t - t0)) s + l
        \f]
 
    where
    \vartable
        Symbol  | Description       | Units
        a       | Amplitude         | -
        f       | Frequency         | [1/s]
        p       | Period            | [s]
        s       | Type scale factor | -
        l       | Type offset level | -
        t       | Time              | [s]
        t0      | Start time offset | [s]
    \endvartable
 
    The dictionary specification would typically resemble this:
    \verbatim
    entry1
    {
        type        sine;
        frequency   10;
        amplitude   0.1;
 
        // A scalar Function1
        scale       2e-6;
        level       2e-6;
    }
    entry2
    {
        type        sine;
        frequency   10;
 
        // A vector Function1
        scale       (1 0.1 0);
        level       (10 1 0);
    }
    \endverbatim
 
    where the entries mean:
    \table
        Property  | Description             | Type | Reqd | Default
        type      | Function type: sine     | word | yes |
        amplitude | Amplitude               | Function1<scalar> | no | 1
        frequency | Frequency [1/s]         | Function1<scalar> | or period |
        period    | Period [s]              | Function1<scalar> | or frequency |
        scale     | Scale factor (Type)     | Function1<Type> | yes |
        level     | Offset level (Type)     | Function1<Type> | yes |
        t0        | Start time offset       | scalar       | no | 0
    \endtable
 
Note
    For slow oscillations it can be more intuitive to specify the period.
 
SourceFiles
    Sine.C
    SineI.H
 
\*---------------------------------------------------------------------------*/
 
#ifndef Function1Types_Sine_H
#define Function1Types_Sine_H
 
#include "Function1.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
namespace Function1Types
{
 
/*---------------------------------------------------------------------------*\
                            Class Sine Declaration
\*---------------------------------------------------------------------------*/
 
template<class Type>
class Sine
:
    public Function1<Type>
{
protected:
 
    // Protected Data
 
        //- Start-time for the function
        scalar t0_;
 
        //- Scalar amplitude of the function (optional)
        autoPtr<Function1<scalar>> amplitude_;
 
        //- Period of the function (or specify frequency)
        autoPtr<Function1<scalar>> period_;
 
        //- Frequency of the function (or specify period)
        autoPtr<Function1<scalar>> frequency_;
 
        //- Scaling factor for the function
        autoPtr<Function1<Type>> scale_;
 
        //- Level to add to the scaled function
        autoPtr<Function1<Type>> level_;
 
 
    // Protected Member Functions
 
        //- The cycle: (freq * time) or (time / period)
        inline scalar cycle(const scalar t) const;
 
        //- Calculated cos value at time t
        inline scalar cosForm(const scalar t) const;
 
        //- Calculated sin value at time t
        inline scalar sinForm(const scalar t) const;
 
        //- Calculated square value at time t.
        //  The positive fraction is 0-1
        inline scalar squareForm(const scalar t, const scalar posFrac) const;
 
        //- Return value for time t, using cos form
        inline Type cosValue(const scalar t) const;
 
        //- Return value for time t, using sin form
        inline Type sinValue(const scalar t) const;
 
        //- Return value for time t, using square form
        inline Type squareValue(const scalar t, const scalar posFrac) const;
 
 
public:
 
    // Runtime type information
    TypeName("sine");
 
 
    // Generated Methods
 
        //- No copy assignment
        void operator=(const Sine<Type>&) = delete;
 
 
    // Constructors
 
        //- Construct from entry name, dictionary and optional registry
        Sine
        (
            const word& entryName,
            const dictionary& dict,
            const objectRegistry* obrPtr = nullptr
        );
 
        //- Copy construct
        explicit Sine(const Sine<Type>& rhs);
 
        //- Construct and return a clone
        virtual tmp<Function1<Type>> clone() const
        {
            return tmp<Function1<Type>>(new Sine<Type>(*this));
        }
 
 
    //- Destructor
    virtual ~Sine() = default;
 
 
    // Member Functions
 
        //- Convert time
        virtual void userTimeToTime(const Time& t);
 
        //- Return value for time t
        virtual inline Type value(const scalar t) const
        {
            return Sine<Type>::sinValue(t);
        }
 
        //- Write in dictionary format
        virtual void writeData(Ostream& os) const;
 
        //- Write coefficient entries in dictionary format
        virtual void writeEntries(Ostream& os) const;
};
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace Function1Types
} // End namespace Foam
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#include "SineI.H"
 
#ifdef NoRepository
    #include "Sine.C"
#endif
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#endif
 
// ************************************************************************* //