Previously the coordinate system functionality was split between
coordinateSystem and coordinateRotation. The coordinateRotation stored
the rotation tensor and handled all tensor transformations.
The functionality has now been revised and consolidated into the
coordinateSystem classes. The sole purpose of coordinateRotation
is now just to provide a selectable mechanism of how to define the
rotation tensor (eg, axis-angle, euler angles, local axes) for user
input, but after providing the appropriate rotation tensor it has
no further influence on the transformations.
--
The coordinateSystem class now contains an origin and a base rotation
tensor directly and various transformation methods.
- The origin represents the "shift" for a local coordinate system.
- The base rotation tensor represents the "tilt" or orientation
of the local coordinate system in general (eg, for mapping
positions), but may require position-dependent tensors when
transforming vectors and tensors.
For some coordinate systems (currently the cylindrical coordinate system),
the rotation tensor required for rotating a vector or tensor is
position-dependent.
The new coordinateSystem and its derivates (cartesian, cylindrical,
indirect) now provide a uniform() method to define if the rotation
tensor is position dependent/independent.
The coordinateSystem transform and invTransform methods are now
available in two-parameter forms for obtaining position-dependent
rotation tensors. Eg,
... = cs.transform(globalPt, someVector);
In some cases it can be useful to use query uniform() to avoid
storage of redundant values.
if (cs.uniform())
{
vector xx = cs.transform(someVector);
}
else
{
List<vector> xx = cs.transform(manyPoints, someVector);
}
Support transform/invTransform for common data types:
(scalar, vector, sphericalTensor, symmTensor, tensor).
====================
Breaking Changes
====================
- These changes to coordinate systems and rotations may represent
a breaking change for existing user coding.
- Relocating the rotation tensor into coordinateSystem itself means
that the coordinate system 'R()' method now returns the rotation
directly instead of the coordinateRotation. The method name 'R()'
was chosen for consistency with other low-level entities (eg,
quaternion).
The following changes will be needed in coding:
Old: tensor rot = cs.R().R();
New: tensor rot = cs.R();
Old: cs.R().transform(...);
New: cs.transform(...);
Accessing the runTime selectable coordinateRotation
has moved to the rotation() method:
Old: Info<< "Rotation input: " << cs.R() << nl;
New: Info<< "Rotation input: " << cs.rotation() << nl;
- Naming consistency changes may also cause code to break.
Old: transformVector()
New: transformPrincipal()
The old method name transformTensor() now simply becomes transform().
====================
New methods
====================
For operations requiring caching of the coordinate rotations, the
'R()' method can be used with multiple input points:
tensorField rots(cs.R(somePoints));
and later
Foam::transformList(rots, someVectors);
The rotation() method can also be used to change the rotation tensor
via a new coordinateRotation definition (issue #879).
The new methods transformPoint/invTransformPoint provide
transformations with an origin offset using Cartesian for both local
and global points. These can be used to determine the local position
based on the origin/rotation without interpreting it as a r-theta-z
value, for example.
================
Input format
================
- Streamline dictionary input requirements
* The default type is cartesian.
* The default rotation type is the commonly used axes rotation
specification (with e1/e2/3), which is assumed if the 'rotation'
sub-dictionary does not exist.
Example,
Compact specification:
coordinateSystem
{
origin (0 0 0);
e2 (0 1 0);
e3 (0.5 0 0.866025);
}
Full specification (also accepts the longer 'coordinateRotation'
sub-dictionary name):
coordinateSystem
{
type cartesian;
origin (0 0 0);
rotation
{
type axes;
e2 (0 1 0);
e3 (0.5 0 0.866025);
}
}
This simplifies the input for many cases.
- Additional rotation specification 'none' (an identity rotation):
coordinateSystem
{
origin (0 0 0);
rotation { type none; }
}
- Additional rotation specification 'axisAngle', which is similar
to the -rotate-angle option for transforming points (issue #660).
For some cases this can be more intuitive.
For example,
rotation
{
type axisAngle;
axis (0 1 0);
angle 30;
}
vs.
rotation
{
type axes;
e2 (0 1 0);
e3 (0.5 0 0.866025);
}
- shorter names (or older longer names) for the coordinate rotation
specification.
euler EulerRotation
starcd STARCDRotation
axes axesRotation
================
Coding Style
================
- use Foam::coordSystem namespace for categories of coordinate systems
(cartesian, cylindrical, indirect). This reduces potential name
clashes and makes a clearer declaration. Eg,
coordSystem::cartesian csys_;
The older names (eg, cartesianCS, etc) remain available via typedefs.
- added coordinateRotations namespace for better organization and
reduce potential name clashes.
- nBoundaryFaces() is often used and is identical to
(nFaces() - nInternalFaces()).
- forward the mesh nInternalFaces() and nBoundaryFaces() to
polyBoundaryMesh as nFaces() and start() respectively,
for use when operating on a polyBoundaryMesh.
STYLE:
- use identity() function with starting offset when creating boundary maps.
labelList map
(
identity(mesh.nBoundaryFaces(), mesh.nInternalFaces())
);
vs.
labelList map(mesh.nBoundaryFaces());
forAll(map, i)
{
map[i] = mesh.nInternalFaces() + i;
}
- avoids compiler ambiguity when virtual methods such as
IOdictionary::read() exist.
- the method was introduced in 1806, and was thus not yet widely used
- aids with detection of excess tokens (issue #762)
- deprecated dictionary::operator[] in favour of the lookup() method
which offers more flexibilty and clarity of purpose.
Additionally, the read<> and get<> forms should generally be used
instead anyhow.
- improvement documentation for surface sampling.
- can now specify alternative sampling scheme for obtaining the
face values instead of just using the "cell" value. For example,
sampleScheme cellPoint;
This can be useful for cases when the surface is close to a boundary
cell and there are large gradients in the sampled field.
- distanceSurface now handles non-closed surfaces more robustly.
Unknown regions (not inside or outside) are marked internally and
excluded from consideration. This allows use of 'signed' surfaces
where not previously possible.
- The iterator for a HashSet dereferences directly to its key.
- Eg,
for (const label patchi : patchSet)
{
...
}
vs.
forAllConstIter(labelHashSet, patchSet, iter)
{
const label patchi = iter.key();
...
}
- both autoPtr and tmp are defined with an implicit construct from
nullptr (but with explicit construct from a pointer to null).
Thus is it safe to use 'nullptr' when returning an empty autoPtr or tmp.
Improve alignment of its behaviour with std::unique_ptr
- element_type typedef
- release() method - identical to ptr() method
- get() method to get the pointer without checking and without releasing it.
- operator*() for dereferencing
Method name changes
- renamed rawPtr() to get()
- renamed rawRef() to ref(), removed unused const version.
Removed methods/operators
- assignment from a raw pointer was deleted (was rarely used).
Can be convenient, but uncontrolled and potentially unsafe.
Do allow assignment from a literal nullptr though, since this
can never leak (and also corresponds to the unique_ptr API).
Additional methods
- clone() method: forwards to the clone() method of the underlying
data object with argument forwarding.
- reset(autoPtr&&) as an alternative to operator=(autoPtr&&)
STYLE: avoid implicit conversion from autoPtr to object type in many places
- existing implementation has the following:
operator const T&() const { return operator*(); }
which means that the following code works:
autoPtr<mapPolyMesh> map = ...;
updateMesh(*map); // OK: explicit dereferencing
updateMesh(map()); // OK: explicit dereferencing
updateMesh(map); // OK: implicit dereferencing
for clarity it may preferable to avoid the implicit dereferencing
- prefer operator* to operator() when deferenced a return value
so it is clearer that a pointer is involve and not a function call
etc Eg, return *meshPtr_; vs. return meshPtr_();
Tracking data classes are no longer templated on the derived cloud type.
The advantage of this is that they can now be passed to sub models. This
should allow continuous phase data to be removed from the parcel
classes. The disadvantage is that every function which once took a
templated TrackData argument now needs an additional TrackCloudType
argument in order to perform the necessary down-casting.
Original commit message:
------------------------
Parallel IO: New collated file format
When an OpenFOAM simulation runs in parallel, the data for decomposed fields and
mesh(es) has historically been stored in multiple files within separate
directories for each processor. Processor directories are named 'processorN',
where N is the processor number.
This commit introduces an alternative "collated" file format where the data for
each decomposed field (and mesh) is collated into a single file, which is
written and read on the master processor. The files are stored in a single
directory named 'processors'.
The new format produces significantly fewer files - one per field, instead of N
per field. For large parallel cases, this avoids the restriction on the number
of open files imposed by the operating system limits.
The file writing can be threaded allowing the simulation to continue running
while the data is being written to file. NFS (Network File System) is not
needed when using the the collated format and additionally, there is an option
to run without NFS with the original uncollated approach, known as
"masterUncollated".
The controls for the file handling are in the OptimisationSwitches of
etc/controlDict:
OptimisationSwitches
{
...
//- Parallel IO file handler
// uncollated (default), collated or masterUncollated
fileHandler uncollated;
//- collated: thread buffer size for queued file writes.
// If set to 0 or not sufficient for the file size threading is not used.
// Default: 2e9
maxThreadFileBufferSize 2e9;
//- masterUncollated: non-blocking buffer size.
// If the file exceeds this buffer size scheduled transfer is used.
// Default: 2e9
maxMasterFileBufferSize 2e9;
}
When using the collated file handling, memory is allocated for the data in the
thread. maxThreadFileBufferSize sets the maximum size of memory in bytes that
is allocated. If the data exceeds this size, the write does not use threading.
When using the masterUncollated file handling, non-blocking MPI communication
requires a sufficiently large memory buffer on the master node.
maxMasterFileBufferSize sets the maximum size in bytes of the buffer. If the
data exceeds this size, the system uses scheduled communication.
The installation defaults for the fileHandler choice, maxThreadFileBufferSize
and maxMasterFileBufferSize (set in etc/controlDict) can be over-ridden within
the case controlDict file, like other parameters. Additionally the fileHandler
can be set by:
- the "-fileHandler" command line argument;
- a FOAM_FILEHANDLER environment variable.
A foamFormatConvert utility allows users to convert files between the collated
and uncollated formats, e.g.
mpirun -np 2 foamFormatConvert -parallel -fileHandler uncollated
An example case demonstrating the file handling methods is provided in:
$FOAM_TUTORIALS/IO/fileHandling
The work was undertaken by Mattijs Janssens, in collaboration with Henry Weller.
Particle collisions with ACMI patches are now handled. The hit detects
whether the location is within the overlap or the coupled region and
recurses, calling the hit routine appropriate for the region.
The low level tracking methods are now more consistently named. There is
now a distinction between tracking to a face and hitting it. Function
object side effects have been moved out of the base layer and into the
parcels on which they are meaningful.
terms of the local barycentric coordinates of the current tetrahedron,
rather than the global coordinate system.
Barycentric tracking works on any mesh, irrespective of mesh quality.
Particles do not get "lost", and tracking does not require ad-hoc
"corrections" or "rescues" to function robustly, because the calculation
of particle-face intersections is unambiguous and reproducible, even at
small angles of incidence.
Each particle position is defined by topology (i.e. the decomposed tet
cell it is in) and geometry (i.e. where it is in the cell). No search
operations are needed on restart or reconstruct, unlike when particle
positions are stored in the global coordinate system.
The particle positions file now contains particles' local coordinates
and topology, rather than the global coordinates and cell. This change
to the output format is not backwards compatible. Existing cases with
Lagrangian data will not restart, but they will still run from time
zero without any modification. This change was necessary in order to
guarantee that the loaded particle is valid, and therefore
fundamentally prevent "loss" and "search-failure" type bugs (e.g.,
2517, 2442, 2286, 1836, 1461, 1341, 1097).
The tracking functions have also been converted to function in terms
of displacement, rather than end position. This helps remove floating
point error issues, particularly towards the end of a tracking step.
Wall bounded streamlines have been removed. The implementation proved
incompatible with the new tracking algorithm. ParaView has a surface
LIC plugin which provides equivalent, or better, functionality.
Additionally, bug report <https://bugs.openfoam.org/view.php?id=2517>
is resolved by this change.
except turbulence and lagrangian which will also be updated shortly.
For example in the nonNewtonianIcoFoam offsetCylinder tutorial the viscosity
model coefficients may be specified in the corresponding "<type>Coeffs"
sub-dictionary:
transportModel CrossPowerLaw;
CrossPowerLawCoeffs
{
nu0 [0 2 -1 0 0 0 0] 0.01;
nuInf [0 2 -1 0 0 0 0] 10;
m [0 0 1 0 0 0 0] 0.4;
n [0 0 0 0 0 0 0] 3;
}
BirdCarreauCoeffs
{
nu0 [0 2 -1 0 0 0 0] 1e-06;
nuInf [0 2 -1 0 0 0 0] 1e-06;
k [0 0 1 0 0 0 0] 0;
n [0 0 0 0 0 0 0] 1;
}
which allows a quick change between models, or using the simpler
transportModel CrossPowerLaw;
nu0 [0 2 -1 0 0 0 0] 0.01;
nuInf [0 2 -1 0 0 0 0] 10;
m [0 0 1 0 0 0 0] 0.4;
n [0 0 0 0 0 0 0] 3;
if quick switching between models is not required.
To support this more convenient parameter specification the inconsistent
specification of seedSampleSet in the streamLine and wallBoundedStreamLine
functionObjects had to be corrected from
// Seeding method.
seedSampleSet uniform; //cloud; //triSurfaceMeshPointSet;
uniformCoeffs
{
type uniform;
axis x; //distance;
// Note: tracks slightly offset so as not to be on a face
start (-1.001 -0.05 0.0011);
end (-1.001 -0.05 1.0011);
nPoints 20;
}
to the simpler
// Seeding method.
seedSampleSet
{
type uniform;
axis x; //distance;
// Note: tracks slightly offset so as not to be on a face
start (-1.001 -0.05 0.0011);
end (-1.001 -0.05 1.0011);
nPoints 20;
}
which also support the "<type>Coeffs" form
// Seeding method.
seedSampleSet
{
type uniform;
uniformCoeffs
{
axis x; //distance;
// Note: tracks slightly offset so as not to be on a face
start (-1.001 -0.05 0.0011);
end (-1.001 -0.05 1.0011);
nPoints 20;
}
}
- The code create a box with a (0,0,0) point.
The new definition is more logical and makes it very easy to grow
the bounding box to include new points. It also simplifies much of
the logic in the constructors.
- Use ROOTVGREAT instead of VGREAT for sizing greatBox and invertedBox.
Avoids some overflow issues reported by Mattijs (thus GREAT has been
used in treeBoundBox), but might still need further revision.
- Constructor for bounding box of a single point.
- add(boundBox), add(point) ...
-> Extend box to enclose the second box or point(s).
Eg,
bb.add(pt);
vs.
bb.min() = Foam::min(bb.min(), pt);
bb.max() = Foam::max(bb.max(), pt);
Also works with other bounding boxes.
Eg,
bb.add(bb2);
// OR
bb += bb2;
vs.
bb.min() = Foam::min(bb.min(), bb2.min());
bb.max() = Foam::max(bb.max(), bb2.max());
'+=' operator allows the reduction to be used in parallel
gather/scatter operations.
A global '+' operator is not currently needed.
Note: may be useful in the future to have a 'clear()' method
that resets to a zero-sized (inverted) box.
STYLE: make many bounding box constructors explicit
