# What does the "maxiters" solver option do?

**URL:** <https://discourse.julialang.org/t/what-does-the-maxiters-solver-option-do/37376>\
**Category:** Modelling & Simulations\
**Tags:** diffeq\
**Created:** [April 11, 2020, 2:29am UTC](https://discourse.julialang.org/t/what-does-the-maxiters-solver-option-do/37376 "2020-04-11T02:29:31Z")\
**Posts on this page:** 1\
**Showing post:** 4

<div class="post-metadata">

**Author:** ![Volker](https://avatars.discourse-cdn.com/v4/letter/v/77aa72/32.png) [@Volker](https://discourse.julialang.org/u/Volker)\
**Post date:** [December 14, 2020, 2:55pm UTC](https://discourse.julialang.org/t/what-does-the-maxiters-solver-option-do/37376/4 "2020-12-14T14:55:14Z")

</div>

> [@ChrisRackauckas](#):
>
> like a long tspan

I have a question. How I can simulate/solve the ODE i.e. for quite long simulation duration? I.e. 2000s.

I ask, because I got this warning as well. Not during the optimization, but later when I just solved the ODE for a long tspan. I tried to increase the maxiter parameter, but then the solving didn´t finish (I let it run in the background for some hours). I could imagine, that simply stacking smaller solvings would work, but I think there is perhaps a more comfortable way, which I don´t know.

I got the warning in the context of the problem, which is described under the following link.

> [@Fitting a dynamic system with an exogenous input (nonhomogenous neural ode) via DiffEqFlux](https://discourse.julialang.org/t/fitting-a-dynamic-system-with-an-exogenous-input-nonhomogenous-neural-ode-via-diffeqflux/44934/24):
>
> I wouldn’t use ReverseDiff or inplace here. Another mistake that you made was that, notice that the solution is a row vector for each output component, so you were broadcasting a row vector against a column vector in the loss function to generate a matrix. That’s not what you wanted. Here’s a code that trains: using DifferentialEquations, Flux, Optim, DiffEqFlux, DiffEqSensitivity, Plots tspan = (0.1f0, Float32(10.0)) tsteps = range(tspan[1], tspan[2], length = 100) t\_vec = collect(tsteps) ex…

---

_[View the full topic](https://discourse.julialang.org/t/what-does-the-maxiters-solver-option-do/37376)._