Add some Mesh methods for handling Z parallelisation
#3245
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| /// Generally, FFTs must be done over the full Z domain. Currently, most | ||
| /// methods using FFTs don't handle parallelising in Z | ||
| #if BOUT_CHECK_LEVEL > 0 | ||
| void checkZSerial(const Mesh& mesh, std::string_view name); |
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warning: no header providing "Mesh" is directly included [misc-include-cleaner]
include/bout/fft.hxx:32:
- #include <bout/array.hxx>
+ #include "bout/field2d.hxx"
+ #include <bout/array.hxx>
src/mesh/impls/bout/boutmesh.cxx
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| BoutReal BoutMesh::GlobalZ(BoutReal jz) const { | ||
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| // Get global Z index as a BoutReal | ||
| BoutReal zglo; |
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warning: variable 'zglo' is not initialized [cppcoreguidelines-init-variables]
Suggested change
| BoutReal zglo; | |
| BoutReal zglo = NAN; |
| parameters["z"] = (loc == CELL_ZLOW) | ||
| ? TWOPI * (iz - 0.5) / static_cast<BoutReal>(msh->LocalNz) | ||
| : TWOPI * iz / static_cast<BoutReal>(msh->LocalNz); | ||
| parameters["z"] = (loc == CELL_ZLOW) ? PI * (msh->GlobalZ(iz) + msh->GlobalZ(iz - 1)) |
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warning: no header providing "CELL_ZLOW" is directly included [misc-include-cleaner]
parameters["z"] = (loc == CELL_ZLOW) ? PI * (msh->GlobalZ(iz) + msh->GlobalZ(iz - 1))
^
Tests are updated because `FakeMesh` has `GlobalZ(z) == z`. This is completely arbitrary, we could have a `GlobalZ` definition that matches `BoutMesh` (`z / nz`) then we wouldn't need to change the tests, but this way is a bit clearer what we're testing.
Also make related methods all `const`
These are just the `BoutReal` overloads of the equivalent `getGlobal?Index` methods
dschwoerer
approved these changes
Jan 13, 2026
| Solver* UNUSED(solver)) | ||
| : Laplacian(opt, loc, mesh_in), A(0.0), C(1.0), D(1.0) { | ||
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| bout::fft::checkZSerial(*localmesh, "`tri` inversion"); |
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Would it be clearer to name this assertZSerial()?
| const BoutReal zglo = getGlobalZIndex(jz); | ||
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| if (symmetricGlobalZ) { | ||
| // With this definition the boundary sits dx/2 away form the first/last inner points |
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Suggested change
| // With this definition the boundary sits dx/2 away form the first/last inner points | |
| // With this definition the boundary sits dz/2 away form the first/last inner points |
| ASSERT2(var.getMesh()->getNguard(direction) >= nGuards); | ||
| ASSERT2(direction == DIRECTION::Z); // Only in Z for now | ||
| ASSERT2(stagger == STAGGER::None); // Staggering not currently supported | ||
| ASSERT2(bout::utils::is_Field3D_v<T>); // Should never need to call this with Field2D |
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Isn't that known at compile time?
So there is no runtime overhead, to have this check always included?
(Same for several of the above)
| interp_from_aligned->calcWeights(zt_prime_from); | ||
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| int yvalid = mesh.LocalNy - 2 * mesh.ystart; | ||
| // avoid overflow - no stencil need more than 5 points |
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Suggested change
| // avoid overflow - no stencil need more than 5 points | |
| // avoid overflow - no stencil needs more than 5 points |
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Supports #3242
Note these don't actually add Z parallelisation, just let us handle it correctly in various places
Mesh::GlobalZfor global Z index in[0, 1]Mesh::getNZPE/getZProcIndexfor Z processor infobout::fft::checkZSerialto guard routines using FFTThese also make a lot of code more consistent between the directions