JuliaControl / JuliaControl/ControlSystems.jl
Accuracy in simulations
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- Dominant language
- Julia
- Stars
- 582
- Forks
- 92
- Avg merge
- 1h 12m
- Merged PRs (30d)
- 2
Description
Since changing to continuous simulations we lose accuracy in lsim compared to the previous zoh method when the input is already zoh. (see https://github.com/JuliaControl/ControlSystems.jl/pull/118#discussion_r167433616)
Step was, for example, exact almost up to machine precision before. We should do at least one of the following
- Default step to
zohwhen the t input is equidistant (this was the previous behaviour) - Allow time responses to accept a tolerance argument that is sent to the numerical solver
- Lower the default tolerance in call to the numerical solver
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with the lsim and time-response entry points discussed in the issue, then read the linked pull request discussion about continuous versus zoh simulation. Compare equidistant zoh-input results with the previous behavior and determine which proposed remedy is appropriate; done means restoring the stated accuracy or providing the requested solver-tolerance behavior.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- julia
- Domain
- backend
- Issue type
- Bug
- Difficulty
- 5/5
- Estimated time
- Over a week
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 28/100