# How to avoid instability in DifferentialEquations?

**URL:** <https://discourse.julialang.org/t/how-to-avoid-instability-in-differentialequations/62739>\
**Category:** Numerics\
**Tags:** ode\
**Created:** [June 11, 2021, 1:33pm UTC](https://discourse.julialang.org/t/how-to-avoid-instability-in-differentialequations/62739 "2021-06-11T13:33:11Z")\
**Posts on this page:** 1\
**Showing post:** 3

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**Author:** ![Luigi\_Marongiu](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/luigi_marongiu/32/7909_2.png) [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)\
**Post date:** [June 12, 2021, 5:58am UTC](https://discourse.julialang.org/t/how-to-avoid-instability-in-differentialequations/62739/3 "2021-06-12T05:58:45Z")

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Thank you! I have tried the new solvers `TRBDF2()` , `KenCarp4()` , or `QNDF()` but I got the same issue reported in the first figure. I then increased the tolerance with `soln = solve( prob, AutoVern7(Rodas5()), callback=delay, abstol=1e-20, reltol=1e-20, tstops=[t_in] )` and I got it through:

 ![CASE_3](https://global.discourse-cdn.com/julialang/original/3X/8/3/830ed021f331ef4bc52b0a6674b92caf6515b701.png)

So the case is closed.  
However, I think the problem is not so much the solver or the ODEs (since they work given certain values) but how to pick the correct parameters. This is the same issue as in my [previous post](https://discourse.julialang.org/t/how-to-bring-differential-equations-to-wanted-value-with-diffeqflux/54167): how to get the range of values for the parameters?  
Ideally, I would need a program that will output something of this sort:

```julia
↓quantity	→time
		    1	2	3	…
10 No	No	Yes	…
20 No	Yes	Yes	…
30 No	Yes	No	…
…

```

Is it possible to get such a list?  
Thanks

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