Type Issue with Transforms.NoTransform!()

[nick4110fi]

I am trying to take an existing 3d parallelized FFT plan function I've written and generalize it to be able to handle 1 and 2d plans as well. Our current function sets up a FFT Plan like so:

dims = (Nx, Ny, Nz)

proc_dims = let pdims = zeros(Int, 2)
     MPI.Dims_create!(mpi_size, pdims)
     pdims[1], pdims[2]
end

transform = (Transforms.FFT!(), Transforms.FFT!(), Transforms.FFT!())

plan = PencilFFTPlan(dims,transform, proc_dims, mpi_comm, float_type)

When the above code is run, things compile correctly for a 3d implementation.

The PencilFFT documentation states that Transforms.NoTransform!() is a valid choice of Transform to give the tuple so I thought the easiest way to generalize this 3d function to operate in 1 or 2d was to pass Transforms.NoTransform!() into the tuple on the dimensions I want the function to leave alone. However when the line

transform = (Transforms.FFT!(), Transforms.FFT!(), Transforms.FFT!())

is changed to

transform = (Transforms.FFT!(), Transforms.NoTransform!(),Transforms.NoTransform!())

I get the following type mismatch error:

ERROR: LoadError: MethodError: Cannot `convert` an object of type 
  PencilFFTs.PencilFFTPlan{ComplexF64, 3, true, 3, 2, 0, PencilFFTs.GlobalFFTParams{Float64, 3, true, Tuple{PencilFFTs.Transforms.FFT!, PencilFFTs.Transforms.NoTransform!, PencilFFTs.Transforms.NoTransform!}}, Tuple{PencilFFTs.PencilPlan1D{ComplexF64, ComplexF64, PencilArrays.Pencils.Pencil{3, 2, StaticPermutations.NoPermutation, Vector{UInt8}}, PencilArrays.Pencils.Pencil{3, 2, StaticPermutations.NoPermutation, Vector{UInt8}}, PencilFFTs.Transforms.FFT!, FFTW.cFFTWPlan{ComplexF64, -1, true, 3, Int64}, FFTW.cFFTWPlan{ComplexF64, 1, true, 3, Int64}}, PencilFFTs.PencilPlan1D{ComplexF64, ComplexF64, PencilArrays.Pencils.Pencil{3, 2, StaticPermutations.Permutation{(2, 1, 3), 3}, Vector{UInt8}}, PencilArrays.Pencils.Pencil{3, 2, StaticPermutations.Permutation{(2, 1, 3), 3}, Vector{UInt8}}, PencilFFTs.Transforms.NoTransform!, PencilFFTs.Transforms.IdentityPlan!, PencilFFTs.Transforms.IdentityPlan!}, PencilFFTs.PencilPlan1D{ComplexF64, ComplexF64, PencilArrays.Pencils.Pencil{3, 2, StaticPermutations.Permutation{(3, 2, 1), 3}, Vector{UInt8}}, PencilArrays.Pencils.Pencil{3, 2, StaticPermutations.Permutation{(3, 2, 1), 3}, Vector{UInt8}}, PencilFFTs.Transforms.NoTransform!, PencilFFTs.Transforms.IdentityPlan!, PencilFFTs.Transforms.IdentityPlan!}}, PencilArrays.Transpositions.PointToPoint, Vector{UInt8}} to an object of type 
  Union{PencilFFTs.PencilFFTPlan{ComplexF64, 3, true, 3, 2, 0, PencilFFTs.GlobalFFTParams{Float64, 3, true, Tuple{PencilFFTs.Transforms.FFT!, PencilFFTs.Transforms.FFT!, PencilFFTs.Transforms.FFT!}}, Tuple{PencilFFTs.PencilPlan1D{ComplexF64, ComplexF64, PencilArrays.Pencils.Pencil{3, 2, StaticPermutations.NoPermutation, Vector{UInt8}}, PencilArrays.Pencils.Pencil{3, 2, StaticPermutations.NoPermutation, Vector{UInt8}}, PencilFFTs.Transforms.FFT!, FFTW.cFFTWPlan{ComplexF64, -1, true, 3, Int64}, FFTW.cFFTWPlan{ComplexF64, 1, true, 3, Int64}}, PencilFFTs.PencilPlan1D{ComplexF64, ComplexF64, PencilArrays.Pencils.Pencil{3, 2, StaticPermutations.Permutation{(2, 1, 3), 3}, Vector{UInt8}}, PencilArrays.Pencils.Pencil{3, 2, StaticPermutations.Permutation{(2, 1, 3), 3}, Vector{UInt8}}, PencilFFTs.Transforms.FFT!, FFTW.cFFTWPlan{ComplexF64, -1, true, 3, Int64}, FFTW.cFFTWPlan{ComplexF64, 1, true, 3, Int64}}, PencilFFTs.PencilPlan1D{ComplexF64, ComplexF64, PencilArrays.Pencils.Pencil{3, 2, StaticPermutations.Permutation{(3, 2, 1), 3}, Vector{UInt8}}, PencilArrays.Pencils.Pencil{3, 2, StaticPermutations.Permutation{(3, 2, 1), 3}, Vector{UInt8}}, PencilFFTs.Transforms.FFT!, FFTW.cFFTWPlan{ComplexF64, -1, true, 3, Int64}, FFTW.cFFTWPlan{ComplexF64, 1, true, 3, Int64}}}, PencilArrays.Transpositions.PointToPoint}, PencilFFTs.PencilFFTPlan{ComplexF64, 3, false, 3, 2, 0, PencilFFTs.GlobalFFTParams{Float64, 3, false, Tuple{PencilFFTs.Transforms.FFT, PencilFFTs.Transforms.FFT, PencilFFTs.Transforms.FFT}}, Tuple{PencilFFTs.PencilPlan1D{ComplexF64, ComplexF64, PencilArrays.Pencils.Pencil{3, 2, StaticPermutations.NoPermutation, Vector{UInt8}}, PencilArrays.Pencils.Pencil{3, 2, StaticPermutations.NoPermutation, Vector{UInt8}}, PencilFFTs.Transforms.FFT, FFTW.cFFTWPlan{ComplexF64, -1, false, 3, Int64}, FFTW.cFFTWPlan{ComplexF64, 1, false, 3, Int64}}, PencilFFTs.PencilPlan1D{ComplexF64, ComplexF64, PencilArrays.Pencils.Pencil{3, 2, StaticPermutations.Permutation{(2, 1, 3), 3}, Vector{UInt8}}, PencilArrays.Pencils.Pencil{3, 2, StaticPermutations.Permutation{(2, 1, 3), 3}, Vector{UInt8}}, PencilFFTs.Transforms.FFT, FFTW.cFFTWPlan{ComplexF64, -1, false, 3, Int64}, FFTW.cFFTWPlan{ComplexF64, 1, false, 3, Int64}}, PencilFFTs.PencilPlan1D{ComplexF64, ComplexF64, PencilArrays.Pencils.Pencil{3, 2, StaticPermutations.Permutation{(3, 2, 1), 3}, Vector{UInt8}}, PencilArrays.Pencils.Pencil{3, 2, StaticPermutations.Permutation{(3, 2, 1), 3}, Vector{UInt8}}, PencilFFTs.Transforms.FFT, FFTW.cFFTWPlan{ComplexF64, -1, false, 3, Int64}, FFTW.cFFTWPlan{ComplexF64, 1, false, 3, Int64}}}, PencilArrays.Transpositions.PointToPoint}}
Closest candidates are:
  convert(::Type{T}, !Matched::T) where T at Base.jl:61

Could this be some sort of type or class issue within PencilArrays? The documentation in PencilFFTs seems pretty clear and I'm wondering if there's an odd interaction with PencilArrays.

[jipolanco]

Seems to work just fine for me.

Here is a full minimal example which runs without error:

using PencilFFTs
using MPI

MPI.Init()

mpi_comm = MPI.COMM_WORLD
mpi_size = MPI.Comm_size(mpi_comm)
const float_type = Float64
Nx, Ny, Nz = 16, 16, 16

dims = (Nx, Ny, Nz)

proc_dims = let pdims = zeros(Int, 2)
     MPI.Dims_create!(mpi_size, pdims)
     pdims[1], pdims[2]
end

# transform = (Transforms.FFT!(), Transforms.FFT!(), Transforms.FFT!())
transform = (Transforms.FFT!(), Transforms.NoTransform!(), Transforms.NoTransform!())

plan = PencilFFTPlan(dims,transform, proc_dims, mpi_comm, float_type)

I get the following plan:

julia> plan = PencilFFTPlan(dims,transform, proc_dims, mpi_comm, float_type)
Transforms: (FFT!, NoTransform!, NoTransform!)
Input type: ComplexF64
Global dimensions: (16, 16, 16) -> (16, 16, 16)
MPI topology: 2D decomposition (1×1 processes)

Which version of PencilFFTs and Julia are you using? Can you provide a full (runnable) minimal example where you get an error?

[jipolanco]

I'm closing this. Feel free to reopen if you still have issues, ideally providing the details mentioned in my previous answer.