Updated the nelson ODE function, (made it nicer to look at) and added parameters #1109
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| sol1 = solve(prob, Rodas5P()) | ||
| sol2 = solve(prob, FBDF()) | ||
| sol3 = solve(prob, lsoda()) | ||
| sol4 = solve(prob, lsoda(), saveat = 1e10) |
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saveat does not change the accuracy of the solution. I'm curious, what are you trying to show with this part?
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When I graph lsoda by itself it produces an incorrect graph, but when I
graph it with the saveat parameter it produces a more accurate looking
graph. I know that it shouldn’t change the time step, but do you know why
lsoda produces a more accurate graphed result with saveat?
DESPOTIC, (the python code that I was comparing my results with) uses
scipy.integrate.odeint which uses lsoda from the FORTRAN library odepack.
And I couldn’t figure out how to get Julia lsoda to work until I used
saveat.
…On Fri, Oct 25, 2024 at 11:17 AM Christopher Rackauckas < ***@***.***> wrote:
***@***.**** commented on this pull request.
------------------------------
In benchmarks/AstroChem/nelson.jmd
<#1109 (comment)>
:
> refsol = solve(prob, Vern9(), abstol=1e-14, reltol=1e-14)
+sol1 = solve(prob, Rodas5P())
+sol2 = solve(prob, FBDF())
+sol3 = solve(prob, lsoda())
+sol4 = solve(prob, lsoda(), saveat = 1e10)
saveat does not change the accuracy of the solution. I'm curious, what
are you trying to show with this part?
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Checklist
contributor guidelines, in particular the SciML Style Guide and
COLPRAC.
Additional context
Here are the Nelson ODE updates! Feel free to take or leave any portion of these changes. I didn't find anywhere to add figures, but the plot that this code produces just shows a funky comparison of different algorithms. When I was searching for accurate, quick algorithms to use, I discovered that lsoda produces accurate results using the saveat parameter, but I'm still unsure as to why.
Thanks!