Include remake in example for ODEProblem

[nonsciencemark]

Adding four lines for remake of ODEProblem would save new users a lot of time remaking the same ODE while changing parameters e.g.,

using SciMLBase
function lorenz!(du,u,p,t)
  du[1] = 10.0(u[2]-u[1])
  du[2] = u[1]*(28.0-u[3]) - u[2]
  du[3] = u[1]*u[2] - (8/3)*u[3]
end
u0 = [1.0;0.0;0.0]
tspan = (0.0,100.0)
prob = ODEProblem(lorenz!,u0,tspan)
  
# Test that it worked
using OrdinaryDiffEq
sol = solve(prob,Tsit5())
using Plots; plot(sol,vars=(1,2,3))

# Try with new u0 and tspan
prob = remake(prob; u0 = [2.0;0.0;0.0], tspan = (0.0,50.0))
sol = solve(prob,Tsit5())
using Plots; plot(sol,vars=(1,2,3))

[ChrisRackauckas]

I think it's reasonable. You mean add it to the first tutorial?

[nonsciencemark]

Yes. I think that examples of remake like above would be useful in in the first tutorial as well as in line 82 in the source so that it's visible with ?ODEProblem¹.

There are also cases in the problem library which ?ODEProblem leads to that create new ODEProblems instead of using remake.

Also the part of the FAQ that mentions this functionality could be renamed so that it is more easily findable. Not sure what synonyms would be appropriate but searching e.g., "update/change/modify parameters/state/tspan" don't seem to get you to this information.

Footnotes

1. maybe this would lead to bloat creep, but it does already have plot ↩

[ChrisRackauckas]

100% agreed.

There are also cases in the problem library which ?ODEProblem leads to that create new ODEProblems instead of using remake.

It would be good to get an issue open there. Those cases were probably just implemented before remake was created, so it was never updated.

Also the part of the FAQ that mentions this functionality could be renamed so that it is more easily findable. Not sure what synonyms would be appropriate but searching e.g., "update/change/modify parameters/state/tspan" don't seem to get you to this information.

"Updating or modifying states and parameters of an already built problem" ?

[nonsciencemark]

"Updating or modifying states and parameters of an already built problem"

I think that would be better, yes.

It would be good to get an issue open there

Will open a new issue over there when I have a bit of time