From cf2b84ef3223a922fe721c74efb349c7e6d71de3 Mon Sep 17 00:00:00 2001
From: Mark Olesen <Mark.Olesen@esi-group.com>
Date: Fri, 15 Nov 2019 13:32:27 +0100
Subject: [PATCH] ENH: add zip/unzip for FieldField

---
 .../test/tensorFieldFields1/Make/files        |   3 +
 .../test/tensorFieldFields1/Make/options      |   2 +
 .../Test-tensorFieldFields1.C                 | 275 ++++++++++++++++++
 .../FieldFields/FieldField/FieldFields.H      |   2 +
 .../scalarFieldField/scalarFieldField.H       |   2 +-
 .../sphericalTensorFieldField.C               |  33 ++-
 .../sphericalTensorFieldField.H               |  20 ++
 .../symmTensorFieldField.C                    |  67 +++++
 .../symmTensorFieldField.H                    |  38 +++
 .../tensorFieldField/tensorFieldField.C       | 171 ++++++++++-
 .../tensorFieldField/tensorFieldField.H       | 105 +++++++
 .../vectorFieldField/vectorFieldField.C       |  64 ++++
 .../vectorFieldField/vectorFieldField.H       |  85 ++++++
 13 files changed, 863 insertions(+), 4 deletions(-)
 create mode 100644 applications/test/tensorFieldFields1/Make/files
 create mode 100644 applications/test/tensorFieldFields1/Make/options
 create mode 100644 applications/test/tensorFieldFields1/Test-tensorFieldFields1.C
 create mode 100644 src/OpenFOAM/fields/FieldFields/vectorFieldField/vectorFieldField.C
 create mode 100644 src/OpenFOAM/fields/FieldFields/vectorFieldField/vectorFieldField.H

diff --git a/applications/test/tensorFieldFields1/Make/files b/applications/test/tensorFieldFields1/Make/files
new file mode 100644
index 0000000000..0bc78a8cea
--- /dev/null
+++ b/applications/test/tensorFieldFields1/Make/files
@@ -0,0 +1,3 @@
+Test-tensorFieldFields1.C
+
+EXE = $(FOAM_USER_APPBIN)/Test-tensorFieldFields1
diff --git a/applications/test/tensorFieldFields1/Make/options b/applications/test/tensorFieldFields1/Make/options
new file mode 100644
index 0000000000..18e6fe47af
--- /dev/null
+++ b/applications/test/tensorFieldFields1/Make/options
@@ -0,0 +1,2 @@
+/* EXE_INC = */
+/* EXE_LIBS = */
diff --git a/applications/test/tensorFieldFields1/Test-tensorFieldFields1.C b/applications/test/tensorFieldFields1/Test-tensorFieldFields1.C
new file mode 100644
index 0000000000..3c93f17753
--- /dev/null
+++ b/applications/test/tensorFieldFields1/Test-tensorFieldFields1.C
@@ -0,0 +1,275 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019 OpenCFD Ltd.
+-------------------------------------------------------------------------------
+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
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    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/>.
+
+Application
+    Test-tensorFieldFields1
+
+\*---------------------------------------------------------------------------*/
+
+#include "tensorField.H"
+#include "FieldFields.H"
+#include "Random.H"
+
+using namespace Foam;
+
+
+template<class Cmpt>
+void printFieldField(const FieldField<Field, Cmpt>& ff)
+{
+    forAll(ff, i)
+    {
+        Info<< ' ' << flatOutput(ff[i]);
+    }
+    Info<< nl;
+}
+
+
+template<class Cmpt, unsigned N>
+void printComponents(const FixedList<FieldField<Field, Cmpt>, N>& cmpts)
+{
+    forAll(cmpts, cmpti)
+    {
+        Info<< cmpti << ':';
+        printFieldField(cmpts[cmpti]);
+    }
+}
+
+
+template<class Cmpt, unsigned N>
+void allocComponents
+(
+    FixedList<FieldField<Field, Cmpt>, N>& cmpts,
+    label dim = 1
+)
+{
+    forAll(cmpts, i)
+    {
+        cmpts[i] = FieldField<Field, Cmpt>(1);
+        cmpts[i].set(0, new Field<Cmpt>(dim, Zero));
+    }
+}
+
+
+vectorField randomVectorField(label size)
+{
+    Random rnd;
+
+    vectorField vf(size);
+
+    forAll(vf, i)
+    {
+        for (direction cmpt=0; cmpt < vector::nComponents; ++cmpt)
+        {
+            vf[i][cmpt] = rnd.position<label>(0, 100);
+        }
+    }
+
+    return vf;
+}
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+int main(int argc, char *argv[])
+{
+    const tensor t19(1, 2, 3, 4, 5, 6, 7, 8, 9);
+
+    // tensorField
+    {
+        Info<< nl << "tensorFieldField" << nl;
+
+        FieldField<Field, tensor> tff1(1);
+        tff1.set(0, new tensorField(1, t19));
+
+        FixedList<FieldField<Field, scalar>, 9> cmpts;
+        allocComponents(cmpts, 1);
+
+        FixedList<FieldField<Field, vector>, 3> slice;
+        allocComponents(slice, 1);
+
+        Info<< "=>";
+        printFieldField(tff1);
+
+        unzip
+        (
+            tff1,
+            cmpts[0], cmpts[1], cmpts[2],
+            cmpts[3], cmpts[4], cmpts[5],
+            cmpts[6], cmpts[7], cmpts[8]
+        );
+
+        Info<< "components" << nl;
+        printComponents(cmpts);
+
+        // Transposed
+        zip
+        (
+            tff1,
+            cmpts[0], cmpts[3], cmpts[6],
+            cmpts[1], cmpts[4], cmpts[7],
+            cmpts[2], cmpts[5], cmpts[8]
+        );
+
+        Info<< "rezip (transposed): "
+            << " => " << tff1 << nl;
+
+
+        // Col / rows
+
+        Info<< nl;
+
+        unzipRows(tff1, slice[0], slice[1], slice[2]);
+        Info<< "rows" << nl;
+        printComponents(slice);
+
+        unzipCols(tff1, slice[0], slice[1], slice[2]);
+        Info<< "cols" << nl;
+        printComponents(slice);
+
+        // forAll(slice, i)
+        // {
+        //     unzipRow(tff1, vector::components(i), slice[i]);
+        //     Info<< "row " << i << ": " << slice[i] << nl;
+        //
+        //     unzipCol(tff1, vector::components(i), slice[i]);
+        //     Info<< "col " << i << ": " << slice[i] << nl;
+        // }
+
+        // Treat columns like rows
+        zipCols(tff1, slice[0], slice[1], slice[2]);
+
+        Info<<"rezip (re-transposed): "
+            <<" => " << tff1 << nl;
+
+        zipRows(tff1, slice[0], slice[1], slice[2]);
+        Info<<"rezip (regular-transposed): "
+            <<" => " << tff1 << nl;
+
+        unzipDiag(tff1, slice[0]);
+        Info<< "diag" << nl;
+        printFieldField(slice[0]);
+    }
+
+
+    // symmTensorField
+    {
+        Info<< nl << "symmTensorField" << nl;
+
+        FieldField<Field, symmTensor> sf1(1);
+        sf1.set(0, new symmTensorField(1, symmTensor(1, 2, 3, 4, 5, 6)));
+
+        FixedList<FieldField<Field, scalar>, 6> cmpts;
+        allocComponents(cmpts, 1);
+
+        FixedList<FieldField<Field, vector>, 1> slice;
+        allocComponents(slice, 1);
+
+        Info<<" =>";
+        printFieldField(sf1);
+
+        unzipDiag(sf1, slice[0]);
+
+        Info<< nl
+            << "diag: ";
+        printFieldField(cmpts[0]);
+
+        unzip
+        (
+            sf1,
+            cmpts[0], cmpts[1], cmpts[2],
+            cmpts[3], cmpts[4],
+            cmpts[5]
+        );
+
+        Info<< "components" << nl;
+        printComponents(cmpts);
+
+        // Transposed
+        zip
+        (
+            sf1,
+            cmpts[5], cmpts[1], cmpts[2],
+            cmpts[3], cmpts[4],
+            cmpts[1]
+        );
+
+        Info<<"rezip (swapped diag): "
+            <<" => " << sf1 << nl;
+    }
+
+    // sphericalTensorField
+    {
+        Info<< nl << "sphericalTensorField" << nl;
+
+        FieldField<Field, sphericalTensor> sf1(1);
+        sf1.set(0, new sphericalTensorField(1, sphericalTensor(4)));
+
+        FixedList<FieldField<Field, scalar>, 1> cmpts;
+        allocComponents(cmpts, 1);
+
+        Info<<" =>";
+        printFieldField(sf1);
+
+        unzip(sf1, cmpts[0]);
+
+        Info<< "components" << nl;
+        printComponents(cmpts);
+    }
+
+    // vectorField
+    {
+        Info<< nl << "vectorField" << nl;
+
+        FieldField<Field, vector> vf1(1);
+        vf1.set(0, new vectorField(randomVectorField(4)));
+
+        FixedList<FieldField<Field, scalar>, 3> cmpts;
+        allocComponents(cmpts, 4);
+
+        Info<< nl
+            << " => " << vf1 << nl;
+
+        unzip(vf1, cmpts[0], cmpts[1], cmpts[2]);
+
+        Info<<"unzip:" << nl
+            << "x : " << cmpts[0] << nl
+            << "y : " << cmpts[1] << nl
+            << "z : " << cmpts[2] << nl
+            << nl;
+
+        // Transposed
+        zip(vf1, cmpts[2], cmpts[0], cmpts[1]);
+
+        Info<<"rezip (rotated): "
+            <<" => " << vf1 << nl;
+    }
+
+    Info<< nl << "End\n" << nl;
+
+    return 0;
+}
+
+
+// ************************************************************************* //
diff --git a/src/OpenFOAM/fields/FieldFields/FieldField/FieldFields.H b/src/OpenFOAM/fields/FieldFields/FieldField/FieldFields.H
index de05d13783..b9369b8f02 100644
--- a/src/OpenFOAM/fields/FieldFields/FieldField/FieldFields.H
+++ b/src/OpenFOAM/fields/FieldFields/FieldField/FieldFields.H
@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011 OpenFOAM Foundation
+    Copyright (C) 2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -34,6 +35,7 @@ Description
 #define FieldFields_H
 
 #include "scalarFieldField.H"
+#include "vectorFieldField.H"
 #include "tensorFieldField.H"
 #include "sphericalTensorFieldField.H"
 
diff --git a/src/OpenFOAM/fields/FieldFields/scalarFieldField/scalarFieldField.H b/src/OpenFOAM/fields/FieldFields/scalarFieldField/scalarFieldField.H
index 7e8be3478f..9c38fbf5d2 100644
--- a/src/OpenFOAM/fields/FieldFields/scalarFieldField/scalarFieldField.H
+++ b/src/OpenFOAM/fields/FieldFields/scalarFieldField/scalarFieldField.H
@@ -38,8 +38,8 @@ SourceFiles
 #ifndef scalarFieldField_H
 #define scalarFieldField_H
 
+#include "scalarField.H"
 #include "FieldField.H"
-#include "scalar.H"
 
 #define TEMPLATE template<template<class> class Field>
 #include "FieldFieldFunctionsM.H"
diff --git a/src/OpenFOAM/fields/FieldFields/sphericalTensorFieldField/sphericalTensorFieldField.C b/src/OpenFOAM/fields/FieldFields/sphericalTensorFieldField/sphericalTensorFieldField.C
index dcc5b77a2d..b9fa881af0 100644
--- a/src/OpenFOAM/fields/FieldFields/sphericalTensorFieldField/sphericalTensorFieldField.C
+++ b/src/OpenFOAM/fields/FieldFields/sphericalTensorFieldField/sphericalTensorFieldField.C
@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011 OpenFOAM Foundation
+    Copyright (C) 2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -33,12 +34,42 @@ Description
 #define TEMPLATE template<template<class> class Field>
 #include "FieldFieldFunctionsM.C"
 
+// * * * * * * * * * * * * * * * Global Functions  * * * * * * * * * * * * * //
+
+template<template<class> class Field, class Cmpt>
+void Foam::zip
+(
+    FieldField<Field, SphericalTensor<Cmpt>>& result,
+    const FieldField<Field, Cmpt>& ii
+)
+{
+    forAll(result, i)
+    {
+        Foam::zip(result[i], ii[i]);
+    }
+}
+
+
+template<template<class> class Field, class Cmpt>
+void Foam::unzip
+(
+    const FieldField<Field, SphericalTensor<Cmpt>>& input,
+    FieldField<Field, Cmpt>& ii
+)
+{
+    forAll(input, i)
+    {
+        Foam::unzip(input[i], ii[i]);
+    }
+}
+
+
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 namespace Foam
 {
 
-// * * * * * * * * * * * * * * * global functions  * * * * * * * * * * * * * //
+// * * * * * * * * * * * * * * * Global Functions  * * * * * * * * * * * * * //
 
 UNARY_FUNCTION(scalar, sphericalTensor, tr)
 UNARY_FUNCTION(sphericalTensor, sphericalTensor, sph)
diff --git a/src/OpenFOAM/fields/FieldFields/sphericalTensorFieldField/sphericalTensorFieldField.H b/src/OpenFOAM/fields/FieldFields/sphericalTensorFieldField/sphericalTensorFieldField.H
index 27be9cb500..8511b1c414 100644
--- a/src/OpenFOAM/fields/FieldFields/sphericalTensorFieldField/sphericalTensorFieldField.H
+++ b/src/OpenFOAM/fields/FieldFields/sphericalTensorFieldField/sphericalTensorFieldField.H
@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
+    Copyright (C) 2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -48,6 +49,25 @@ SourceFiles
 namespace Foam
 {
 
+// * * * * * * * * * * * * * * * Global Functions  * * * * * * * * * * * * * //
+
+//- Zip together sphericalTensor field field from components
+template<template<class> class Field, class Cmpt>
+void zip
+(
+    FieldField<Field, SphericalTensor<Cmpt>>& result,
+    const FieldField<Field, Cmpt>& ii
+);
+
+//- Unzip sphericalTensor field field into components
+template<template<class> class Field, class Cmpt>
+void unzip
+(
+    const FieldField<Field, SphericalTensor<Cmpt>>& input,
+    FieldField<Field, Cmpt>& ii
+);
+
+
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 UNARY_FUNCTION(scalar, sphericalTensor, tr)
diff --git a/src/OpenFOAM/fields/FieldFields/symmTensorFieldField/symmTensorFieldField.C b/src/OpenFOAM/fields/FieldFields/symmTensorFieldField/symmTensorFieldField.C
index 6f1382b6ce..cb8cdd7c3b 100644
--- a/src/OpenFOAM/fields/FieldFields/symmTensorFieldField/symmTensorFieldField.C
+++ b/src/OpenFOAM/fields/FieldFields/symmTensorFieldField/symmTensorFieldField.C
@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2015 OpenFOAM Foundation
+    Copyright (C) 2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -33,6 +34,72 @@ Description
 #define TEMPLATE template<template<class> class Field>
 #include "FieldFieldFunctionsM.C"
 
+// * * * * * * * * * * * * * * * Global Functions  * * * * * * * * * * * * * //
+
+template<template<class> class Field, class Cmpt>
+void Foam::zip
+(
+    FieldField<Field, SymmTensor<Cmpt>>& result,
+    const FieldField<Field, Cmpt>& xx,
+    const FieldField<Field, Cmpt>& xy,
+    const FieldField<Field, Cmpt>& xz,
+    const FieldField<Field, Cmpt>& yy,
+    const FieldField<Field, Cmpt>& yz,
+    const FieldField<Field, Cmpt>& zz
+)
+{
+    forAll(result, i)
+    {
+        Foam::zip
+        (
+            result[i],
+            xx[i], xy[i], xz[i],
+            /*yx*/ yy[i], yz[i],
+            /*zx   zy */  zz[i]
+        );
+    }
+}
+
+
+template<template<class> class Field, class Cmpt>
+void Foam::unzip
+(
+    const FieldField<Field, SymmTensor<Cmpt>>& input,
+    FieldField<Field, Cmpt>& xx,
+    FieldField<Field, Cmpt>& xy,
+    FieldField<Field, Cmpt>& xz,
+    FieldField<Field, Cmpt>& yy,
+    FieldField<Field, Cmpt>& yz,
+    FieldField<Field, Cmpt>& zz
+)
+{
+    forAll(input, i)
+    {
+        Foam::unzip
+        (
+            input[i],
+            xx[i], xy[i], xz[i],
+            /*yx*/ yy[i], yz[i],
+            /*zx   zy */  zz[i]
+        );
+    }
+}
+
+
+template<template<class> class Field, class Cmpt>
+void Foam::unzipDiag
+(
+    const FieldField<Field, SymmTensor<Cmpt>>& input,
+    FieldField<Field, Vector<Cmpt>>& result
+)
+{
+    forAll(input, i)
+    {
+        Foam::unzipDiag(input[i], result[i]);
+    }
+}
+
+
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 namespace Foam
diff --git a/src/OpenFOAM/fields/FieldFields/symmTensorFieldField/symmTensorFieldField.H b/src/OpenFOAM/fields/FieldFields/symmTensorFieldField/symmTensorFieldField.H
index c0fb41afd4..37de06d7a2 100644
--- a/src/OpenFOAM/fields/FieldFields/symmTensorFieldField/symmTensorFieldField.H
+++ b/src/OpenFOAM/fields/FieldFields/symmTensorFieldField/symmTensorFieldField.H
@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
+    Copyright (C) 2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -48,6 +49,43 @@ SourceFiles
 namespace Foam
 {
 
+// * * * * * * * * * * * * * * * Global Functions  * * * * * * * * * * * * * //
+
+//- Zip together symmTensor field field from components
+template<template<class> class Field, class Cmpt>
+void zip
+(
+    FieldField<Field, SymmTensor<Cmpt>>& result,
+    const FieldField<Field, Cmpt>& xx,
+    const FieldField<Field, Cmpt>& xy,
+    const FieldField<Field, Cmpt>& xz,
+    const FieldField<Field, Cmpt>& yy,
+    const FieldField<Field, Cmpt>& yz,
+    const FieldField<Field, Cmpt>& zz
+);
+
+//- Unzip symmTensor field field into components
+template<template<class> class Field, class Cmpt>
+void unzip
+(
+    const FieldField<Field, SymmTensor<Cmpt>>& input,
+    FieldField<Field, Cmpt>& xx,
+    FieldField<Field, Cmpt>& xy,
+    FieldField<Field, Cmpt>& xz,
+    FieldField<Field, Cmpt>& yy,
+    FieldField<Field, Cmpt>& yz,
+    FieldField<Field, Cmpt>& zz
+);
+
+//- Extract a symmTensor field field diagonal
+template<template<class> class Field, class Cmpt>
+void unzipDiag
+(
+    const FieldField<Field, SymmTensor<Cmpt>>& input,
+    FieldField<Field, Vector<Cmpt>>& result
+);
+
+
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 UNARY_FUNCTION(symmTensor, vector, sqr)
diff --git a/src/OpenFOAM/fields/FieldFields/tensorFieldField/tensorFieldField.C b/src/OpenFOAM/fields/FieldFields/tensorFieldField/tensorFieldField.C
index e0c58a36a1..62747be172 100644
--- a/src/OpenFOAM/fields/FieldFields/tensorFieldField/tensorFieldField.C
+++ b/src/OpenFOAM/fields/FieldFields/tensorFieldField/tensorFieldField.C
@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011 OpenFOAM Foundation
+    Copyright (C) 2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -33,12 +34,178 @@ Description
 #define TEMPLATE template<template<class> class Field>
 #include "FieldFieldFunctionsM.C"
 
+// * * * * * * * * * * * * * * * Global Functions  * * * * * * * * * * * * * //
+
+template<template<class> class Field, class Cmpt>
+void Foam::zip
+(
+    FieldField<Field, Tensor<Cmpt>>& result,
+    const FieldField<Field, Cmpt>& xx,
+    const FieldField<Field, Cmpt>& xy,
+    const FieldField<Field, Cmpt>& xz,
+    const FieldField<Field, Cmpt>& yx,
+    const FieldField<Field, Cmpt>& yy,
+    const FieldField<Field, Cmpt>& yz,
+    const FieldField<Field, Cmpt>& zx,
+    const FieldField<Field, Cmpt>& zy,
+    const FieldField<Field, Cmpt>& zz
+)
+{
+    forAll(result, i)
+    {
+        Foam::zip
+        (
+            result[i],
+            xx[i], xy[i], xz[i],
+            yx[i], yy[i], yz[i],
+            zx[i], zy[i], zz[i]
+        );
+    }
+}
+
+
+template<template<class> class Field, class Cmpt>
+void Foam::unzip
+(
+    const FieldField<Field, Tensor<Cmpt>>& input,
+    FieldField<Field, Cmpt>& xx,
+    FieldField<Field, Cmpt>& xy,
+    FieldField<Field, Cmpt>& xz,
+    FieldField<Field, Cmpt>& yx,
+    FieldField<Field, Cmpt>& yy,
+    FieldField<Field, Cmpt>& yz,
+    FieldField<Field, Cmpt>& zx,
+    FieldField<Field, Cmpt>& zy,
+    FieldField<Field, Cmpt>& zz
+)
+{
+    forAll(input, i)
+    {
+        Foam::unzip
+        (
+            input[i],
+            xx[i], xy[i], xz[i],
+            yx[i], yy[i], yz[i],
+            zx[i], zy[i], zz[i]
+        );
+    }
+}
+
+
+template<template<class> class Field, class Cmpt>
+void Foam::zipRows
+(
+    FieldField<Field, Tensor<Cmpt>>& result,
+    const FieldField<Field, Vector<Cmpt>>& x,
+    const FieldField<Field, Vector<Cmpt>>& y,
+    const FieldField<Field, Vector<Cmpt>>& z
+)
+{
+    forAll(result, i)
+    {
+        Foam::zipRows(result[i], x[i], y[i], z[i]);
+    }
+}
+
+
+template<template<class> class Field, class Cmpt>
+void Foam::zipCols
+(
+    FieldField<Field, Tensor<Cmpt>>& result,
+    const FieldField<Field, Vector<Cmpt>>& x,
+    const FieldField<Field, Vector<Cmpt>>& y,
+    const FieldField<Field, Vector<Cmpt>>& z
+)
+{
+    forAll(result, i)
+    {
+        Foam::zipCols(result[i], x[i], y[i], z[i]);
+    }
+}
+
+
+template<template<class> class Field, class Cmpt>
+void Foam::unzipRows
+(
+    const FieldField<Field, Tensor<Cmpt>>& input,
+    FieldField<Field, Vector<Cmpt>>& x,
+    FieldField<Field, Vector<Cmpt>>& y,
+    FieldField<Field, Vector<Cmpt>>& z
+)
+{
+    forAll(input, i)
+    {
+        Foam::unzipRows(input[i], x[i], y[i], z[i]);
+    }
+}
+
+
+template<template<class> class Field, class Cmpt>
+void Foam::unzipCols
+(
+    const FieldField<Field, Tensor<Cmpt>>& input,
+    FieldField<Field, Vector<Cmpt>>& x,
+    FieldField<Field, Vector<Cmpt>>& y,
+    FieldField<Field, Vector<Cmpt>>& z
+)
+{
+    forAll(input, i)
+    {
+        Foam::unzipCols(input[i], x[i], y[i], z[i]);
+    }
+}
+
+
+template<template<class> class Field, class Cmpt>
+void Foam::unzipRow
+(
+    const FieldField<Field, Tensor<Cmpt>>& input,
+    const vector::components cmpt,
+    FieldField<Field, Vector<Cmpt>>& result
+)
+{
+    forAll(input, i)
+    {
+        Foam::unzipRow(input[i], cmpt, result[i]);
+    }
+}
+
+
+template<template<class> class Field, class Cmpt>
+void Foam::unzipCol
+(
+    const FieldField<Field, Tensor<Cmpt>>& input,
+    const vector::components cmpt,
+    FieldField<Field, Vector<Cmpt>>& result
+)
+{
+    forAll(input, i)
+    {
+        Foam::unzipCol(input[i], cmpt, result[i]);
+    }
+}
+
+
+template<template<class> class Field, class Cmpt>
+void Foam::unzipDiag
+(
+    const FieldField<Field, Tensor<Cmpt>>& input,
+    FieldField<Field, Vector<Cmpt>>& result
+)
+{
+    forAll(input, i)
+    {
+        Foam::unzipDiag(input[i], result[i]);
+    }
+}
+
+
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 namespace Foam
 {
 
-// * * * * * * * * * * * * * * * global operators  * * * * * * * * * * * * * //
+// * * * * * * * * * * * * * * * Global Operators  * * * * * * * * * * * * * //
 
 UNARY_FUNCTION(scalar, tensor, tr)
 UNARY_FUNCTION(sphericalTensor, tensor, sph)
@@ -57,7 +224,7 @@ UNARY_FUNCTION(vector, symmTensor, eigenValues)
 UNARY_FUNCTION(symmTensor, symmTensor, eigenVectors)
 
 
-// * * * * * * * * * * * * * * * global operators  * * * * * * * * * * * * * //
+// * * * * * * * * * * * * * * * Global Operators  * * * * * * * * * * * * * //
 
 UNARY_OPERATOR(vector, tensor, *, hdual)
 UNARY_OPERATOR(tensor, vector, *, hdual)
diff --git a/src/OpenFOAM/fields/FieldFields/tensorFieldField/tensorFieldField.H b/src/OpenFOAM/fields/FieldFields/tensorFieldField/tensorFieldField.H
index 44664163fa..af817dddd1 100644
--- a/src/OpenFOAM/fields/FieldFields/tensorFieldField/tensorFieldField.H
+++ b/src/OpenFOAM/fields/FieldFields/tensorFieldField/tensorFieldField.H
@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
+    Copyright (C) 2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -49,6 +50,110 @@ SourceFiles
 namespace Foam
 {
 
+// * * * * * * * * * * * * * * * Global Functions  * * * * * * * * * * * * * //
+
+//- Zip together tensor field field from components
+template<template<class> class Field, class Cmpt>
+void zip
+(
+    FieldField<Field, Tensor<Cmpt>>& result,
+    const FieldField<Field, Cmpt>& xx,
+    const FieldField<Field, Cmpt>& xy,
+    const FieldField<Field, Cmpt>& xz,
+    const FieldField<Field, Cmpt>& yx,
+    const FieldField<Field, Cmpt>& yy,
+    const FieldField<Field, Cmpt>& yz,
+    const FieldField<Field, Cmpt>& zx,
+    const FieldField<Field, Cmpt>& zy,
+    const FieldField<Field, Cmpt>& zz
+);
+
+//- Unzip tensor field field into components
+template<template<class> class Field, class Cmpt>
+void unzip
+(
+    const FieldField<Field, Tensor<Cmpt>>& input,
+    FieldField<Field, Cmpt>& xx,
+    FieldField<Field, Cmpt>& xy,
+    FieldField<Field, Cmpt>& xz,
+    FieldField<Field, Cmpt>& yx,
+    FieldField<Field, Cmpt>& yy,
+    FieldField<Field, Cmpt>& yz,
+    FieldField<Field, Cmpt>& zx,
+    FieldField<Field, Cmpt>& zy,
+    FieldField<Field, Cmpt>& zz
+);
+
+
+//- Zip together tensor field field from row components
+template<template<class> class Field, class Cmpt>
+void zipRows
+(
+    FieldField<Field, Tensor<Cmpt>>& result,
+    const FieldField<Field, Vector<Cmpt>>& x,
+    const FieldField<Field, Vector<Cmpt>>& y,
+    const FieldField<Field, Vector<Cmpt>>& z
+);
+
+//- Zip together tensor field from column components
+template<template<class> class Field, class Cmpt>
+void zipCols
+(
+    FieldField<Field, Tensor<Cmpt>>& result,
+    const FieldField<Field, Vector<Cmpt>>& x,
+    const FieldField<Field, Vector<Cmpt>>& y,
+    const FieldField<Field, Vector<Cmpt>>& z
+);
+
+
+//- Extract tensor field field rows
+template<template<class> class Field, class Cmpt>
+void unzipRows
+(
+    const FieldField<Field, Tensor<Cmpt>>& input,
+    FieldField<Field, Vector<Cmpt>>& x,
+    FieldField<Field, Vector<Cmpt>>& y,
+    FieldField<Field, Vector<Cmpt>>& z
+);
+
+//- Extract tensor field field columns
+template<template<class> class Field, class Cmpt>
+void unzipCols
+(
+    const FieldField<Field, Tensor<Cmpt>>& input,
+    FieldField<Field, Vector<Cmpt>>& x,
+    FieldField<Field, Vector<Cmpt>>& y,
+    FieldField<Field, Vector<Cmpt>>& z
+);
+
+
+//- Extract a tensor field field row (x,y,z) == (0,1,2)
+template<template<class> class Field, class Cmpt>
+void unzipRow
+(
+    const FieldField<Field, Tensor<Cmpt>>& input,
+    const vector::components cmpt,
+    FieldField<Field, Vector<Cmpt>>& result
+);
+
+//- Extract a tensor field field column (x,y,z) == (0,1,2)
+template<template<class> class Field, class Cmpt>
+void unzipCol
+(
+    const FieldField<Field, Tensor<Cmpt>>& input,
+    const vector::components cmpt,
+    FieldField<Field, Vector<Cmpt>>& result
+);
+
+//- Extract a tensor field field diagonal
+template<template<class> class Field, class Cmpt>
+void unzipDiag
+(
+    const FieldField<Field, Tensor<Cmpt>>& input,
+    FieldField<Field, Vector<Cmpt>>& result
+);
+
+
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 UNARY_FUNCTION(scalar, tensor, tr)
diff --git a/src/OpenFOAM/fields/FieldFields/vectorFieldField/vectorFieldField.C b/src/OpenFOAM/fields/FieldFields/vectorFieldField/vectorFieldField.C
new file mode 100644
index 0000000000..b7e1cdac15
--- /dev/null
+++ b/src/OpenFOAM/fields/FieldFields/vectorFieldField/vectorFieldField.C
@@ -0,0 +1,64 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019 OpenCFD Ltd.
+-------------------------------------------------------------------------------
+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
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    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/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "vectorFieldField.H"
+
+// * * * * * * * * * * * * * * * Global Functions  * * * * * * * * * * * * * //
+
+template<template<class> class Field, class Cmpt>
+void Foam::zip
+(
+    FieldField<Field, Vector<Cmpt>>& result,
+    const FieldField<Field, Cmpt>& x,
+    const FieldField<Field, Cmpt>& y,
+    const FieldField<Field, Cmpt>& z
+)
+{
+    forAll(result, i)
+    {
+        Foam::zip(result[i], x[i], y[i], z[i]);
+    }
+}
+
+
+template<template<class> class Field, class Cmpt>
+void Foam::unzip
+(
+    const FieldField<Field, Vector<Cmpt>>& input,
+    FieldField<Field, Cmpt>& x,
+    FieldField<Field, Cmpt>& y,
+    FieldField<Field, Cmpt>& z
+)
+{
+    forAll(input, i)
+    {
+        Foam::unzip(input[i], x[i], y[i], z[i]);
+    }
+}
+
+
+// ************************************************************************* //
diff --git a/src/OpenFOAM/fields/FieldFields/vectorFieldField/vectorFieldField.H b/src/OpenFOAM/fields/FieldFields/vectorFieldField/vectorFieldField.H
new file mode 100644
index 0000000000..9e0355f3dc
--- /dev/null
+++ b/src/OpenFOAM/fields/FieldFields/vectorFieldField/vectorFieldField.H
@@ -0,0 +1,85 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2019 OpenCFD Ltd.
+-------------------------------------------------------------------------------
+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
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    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/>.
+
+InClass
+    Foam::vectorFieldField
+
+Description
+    Specialisation of FieldField\<T\> for vector.
+
+SourceFiles
+    vectorFieldField.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef vectorFieldField_H
+#define vectorFieldField_H
+
+#include "scalarFieldField.H"
+#include "vectorField.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+// * * * * * * * * * * * * * * * Global Functions * * * * * * * * * * * * * * //
+
+//- Compose a vector field field from components
+template<template<class> class Field, class Cmpt>
+void zip
+(
+    FieldField<Field, Vector<Cmpt>>& result,
+    const FieldField<Field, Cmpt>& x,
+    const FieldField<Field, Cmpt>& y,
+    const FieldField<Field, Cmpt>& z
+);
+
+//- Unzip vector field field into components
+template<template<class> class Field, class Cmpt>
+void unzip
+(
+    const FieldField<Field, Vector<Cmpt>>& input,
+    FieldField<Field, Cmpt>& x,
+    FieldField<Field, Cmpt>& y,
+    FieldField<Field, Cmpt>& z
+);
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#ifdef NoRepository
+    #include "vectorFieldField.C"
+#endif
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //