fvExpressionField.H

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-------------------------------------------------------------------------------
    Copyright (C) 2021 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.
 
    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
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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::functionObjects::fvExpressionField
 
Group
    grpFieldFunctionObjects
 
Description
    Function object that generates or modifies a field based on expressions.
 
Usage
    A minimal example:
    \verbatim
    exprFieldFO
    {
        // Mandatory entries
        type            exprField;
        libs            (fieldFunctionObjects);
        field           <word>;  // pTotal;
        expression      "p + 0.5*(rho*magSqr(U))";
 
        // Optional entries
        action          <word>;            // none, new, modify
        autowrite       <bool>;
        store           <bool>;
        dimensions      [ Pa ];         // for new field only
        readFields      (<wordList>);   // (p U rho), for post-process mode only
        useNamePrefix   false;          // for new field only
 
        // Inherited entries
        ...
    }
 
    // Modify an existing field
    <name2>
    {
        type    exprField;
        libs    (fieldFunctionObjects);
        field   pTotal;
        action  modify;
 
        // Static pressure only in these regions
        fieldMask   "(mag(pos()) < 0.05) && (pos().y() > 0)";
        expression  "p";
    }
    \endverbatim
 
    where the entries mean:
    \table
      Property     | Description                        | Type   | Reqd | Deflt
      type         | Type name: exprField               | word   | yes  |
      libs         | Libraries: fieldFunctionObjects    | wordList | yes |
      field        | Name of input or output field      | word   | yes |
      expression   | Field evaluation expression        | string | yes |
      action       | Type of operation: see below       | word   | no  | new
      autowrite    | Add AUTO_WRITE to created field    | bool   | no  | false
      store        | Store calculated field             | bool   | no  | true
      fieldMask    | Masking as logical expression      | string | no  | ""
      dimensions | Apply specified dimensions to created field | dim-spec | no |
      readFields   | Preload named fields (post-process mode) | wordList | no |
      useNamePrefix | Add prefix scoping to output name | bool   | no  | false
    \endtable
 
    Options for the \c action entry:
    \plaintable
      none          | No operation
      new           | Define field based on expression (default)
      modify        | Adjust field according to expression and fieldMask
    \endplaintable
 
    The inherited entries are elaborated in:
      - \link fieldExpression.H \endlink
 
Note
    The \c useNamePrefix entry is always ignored for the \c modify action.
 
SourceFiles
    fvExpressionField.C
 
\*---------------------------------------------------------------------------*/
 
#ifndef Foam_functionObjects_fvExpressionField_H
#define Foam_functionObjects_fvExpressionField_H
 
#include "fvMeshFunctionObject.H"
#include "volumeExprDriver.H"
#include "Enum.H"
#include "dimensionSet.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
namespace functionObjects
{
 
/*---------------------------------------------------------------------------*\
                      Class fvExpressionField Declaration
\*---------------------------------------------------------------------------*/
 
class fvExpressionField
:
    public fvMeshFunctionObject
{
public:
 
    // Public Data Types
 
        //- Action type enumeration
        enum actionType : unsigned char
        {
            opNone = 0,     
            opNew,          
            opModify        
        };
 
        //- Action type names
        static const Enum<actionType> actionNames_;
 
 
protected:
 
    // Private Data
 
        //- The context dictionary
        dictionary dict_;
 
        //- Name of the field
        word fieldName_;
 
        //- Names fields to preload
        wordList preloadFields_;
 
        //- The field-mask expression (modify mode)
        expressions::exprString maskExpr_;
 
        //- Expression to evaluate
        expressions::exprString valueExpr_;
 
        //- Dimensions for new field
        dimensionSet dimensions_;
 
        //- Operation mode
        actionType action_;
 
        //- Set AUTO_WRITE for new field
        bool autowrite_;
 
        //- Store calculated field
        bool store_;
 
        //- True if dimensions_ should be used (creation)
        bool hasDimensions_;
 
        //- Load fields from files (not from objectRegistry)
        bool loadFromFiles_;
 
        autoPtr<expressions::volumeExprDriver> driver_;
 
 
    // Private Member Functions
 
        //- Attempt load from io, store on database if successful
        template<class FieldType>
        bool loadAndStore(const IOobject& io);
 
        //- Forward to loadAndStore for supported types
        template<class Type>
        bool loadField(const IOobject& io);
 
        //- Attempt to load specified fields
        label loadFields(const UList<word>& fieldSet_);
 
        //- Sets the values of the output field based on a condition
        template<class GeoField>
        bool setField
        (
            GeoField& output,
            const GeoField& evaluated,
            const boolField& cond
        );
 
        //- Execute the requested action
        bool performAction(bool doWrite);
 
public:
 
    //- Runtime type information
    TypeName("exprField");
 
 
    // Constructors
 
        //- Construct from name, Time and dictionary
        fvExpressionField
        (
            const word& name,
            const Time& runTime,
            const dictionary& dict,
            const bool loadFromFiles = false
        );
 
        //- No copy construct
        fvExpressionField(const fvExpressionField&) = delete;
 
        //- No copy assignment
        void operator=(const fvExpressionField&) = delete;
 
 
    //- Destructor
    virtual ~fvExpressionField();
 
 
    // Member Functions
 
        //- Qualified/unqualified field name (depends on action)
        virtual word fieldName() const;
 
        //- Read the function-object dictionary
        virtual bool read(const dictionary& dict);
 
        //- Execute the function-object operations
        virtual bool execute();
 
        //- Write the function-object results
        virtual bool write();
};
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace functionObjects
} // End namespace Foam
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#endif
 
// ************************************************************************* //