Add Spin/Pol iterator on AbstractProcessDefinition #107
Labels
06 - Feature-request
Missing feature or functionality
Milestone
Comments
SimeonEhrig
pushed a commit
that referenced
this issue
Sep 12, 2024
…118) As the title says, this adds an iterator to yield all possible combinations of spins and polarizations allowed by a process' set `spin_pols()`. For example: ```Julia julia> using QEDbase; using QEDcore; using QEDprocesses; julia> proc = ScatteringProcess((Photon(), Photon(), Photon(), Electron()), (Photon(), Electron()), (SyncedPolarization(1), SyncedPolarization(2), SyncedPolarization(1), SpinUp()), (SyncedPolarization(2), AllSpin())) generic QED process incoming: photon (synced polarization 1), photon (synced polarization 2), photon (synced polarization 1), electron (spin up) outgoing: photon (synced polarization 2), electron (all spins) julia> for sp_combo in spin_pols_iter(proc) println(sp_combo) end ((x-polarized, x-polarized, x-polarized, spin up), (x-polarized, spin up)) ((y-polarized, x-polarized, y-polarized, spin up), (x-polarized, spin up)) ((x-polarized, y-polarized, x-polarized, spin up), (y-polarized, spin up)) ((y-polarized, y-polarized, y-polarized, spin up), (y-polarized, spin up)) ((x-polarized, x-polarized, x-polarized, spin up), (x-polarized, spin down)) ((y-polarized, x-polarized, y-polarized, spin up), (x-polarized, spin down)) ((x-polarized, y-polarized, x-polarized, spin up), (y-polarized, spin down)) ((y-polarized, y-polarized, y-polarized, spin up), (y-polarized, spin down)) julia> length(spin_pols_iter(proc)) 8 ``` The above is also a `jldoctest`. As a side-note I also added an alias of `SyncedPol` to `SyncedPolarization`. The code is not incredibly concise and also not incredibly fast, but for the reasonable cases that I tested `@benchmark` reports well under 1ms. Since I don't think this iterator would be the critical path of anything this should be fine. The only problem I could see is that due to everything using `Tuple`s in its arguments, the compile time is relatively large. If this becomes a problem we could change it to using `Vector`s instead, likely trading some runtime for much better compile time. Fixes #107
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
It would be nice to have an iterator to iterate over all possible definite spin/pol configurations of a given process. Something like a function
definite_spin_pols(proc::AbstractProcessDefinition)that would allow code such asThe
lengthof this iterator corresponds to themultiplicityof the whole process.The text was updated successfully, but these errors were encountered: