# How to demonstrate the calculation process and progress of the solver LINDOGlobal

**URL:** <https://discuss.ampl.com/t/how-to-demonstrate-the-calculation-process-and-progress-of-the-solver-lindoglobal/443>\
**Category:** Support\
**Tags:** displays-results\
**Created:** [March 19, 2023, 2:55pm UTC](https://discuss.ampl.com/t/how-to-demonstrate-the-calculation-process-and-progress-of-the-solver-lindoglobal/443 "2023-03-19T14:55:19Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![LealzzzZZZ](https://avatars.discourse-cdn.com/v4/letter/l/c89c15/32.png) [@LealzzzZZZ](https://discuss.ampl.com/u/LealzzzZZZ)\
**Post date:** [March 19, 2023, 2:55pm UTC](https://discuss.ampl.com/t/how-to-demonstrate-the-calculation-process-and-progress-of-the-solver-lindoglobal/443/1 "2023-03-19T14:55:19Z")

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How to demonstrate the calculation process and progress of the solver LINDOGlobal.

The calculation process for most problems is time-consuming and the calculation progress cannot be mastered.

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**Author:** ![4er](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.ampl.com/4er/32/530_2.png) [@4er](https://discuss.ampl.com/u/4er)\
**Post date:** [March 19, 2023, 3:19pm UTC](https://discuss.ampl.com/t/how-to-demonstrate-the-calculation-process-and-progress-of-the-solver-lindoglobal/443/2 "2023-03-19T15:19:43Z")

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To see a progress log from the LINDO Global solver while it is running, set the option `outlev=1`. If you are not currently setting any options for LINDO Global, then you can specify the option like this:

```auto
option solver lindoglobal;
option lindoglobal_options 'outlev=1';

```

(If you are already setting a `lindoglobal_options` string, then add `outlev=1` to it.) For more information, visit our [LINDO Global for AMPL](https://dev.ampl.com/solvers/lindoglobal/index.html) page.

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**Author:** ![LealzzzZZZ](https://avatars.discourse-cdn.com/v4/letter/l/c89c15/32.png) [@LealzzzZZZ](https://discuss.ampl.com/u/LealzzzZZZ)\
**Post date:** [March 19, 2023, 3:58pm UTC](https://discuss.ampl.com/t/how-to-demonstrate-the-calculation-process-and-progress-of-the-solver-lindoglobal/443/3 "2023-03-19T15:58:01Z")

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Thank you very much, but I still have no expectation of the solution time. May I ask which label I should focus on, and how to improve the speed of solving nonlinear problems.

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**Author:** ![4er](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.ampl.com/4er/32/530_2.png) [@4er](https://discuss.ampl.com/u/4er)\
**Post date:** [March 20, 2023, 4:21pm UTC](https://discuss.ampl.com/t/how-to-demonstrate-the-calculation-process-and-progress-of-the-solver-lindoglobal/443/4 "2023-03-20T16:21:56Z")

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In LINDO Global’s `outlev=1` output, there is some information on how much time the solver has taken so far. There is no information on how long the total solution time will be, however, because there is no way for the solver’s algorithm to know that.

Nonlinear global optimization is a very hard problem, so there can be no simple advice for improving the speed of the solver. If you can post a file containing all of the solver’s output, it may be possible to give some general advice. However, you may need to stop the solver before it has proved optimality, and take the best solution it has found – which may be an optimal solution, or very close to one. You can set LINDO Global’s options as, for example,

```auto
option lindoglobal_options 'outlev=1 maxtime=1000';

```

to specify a maximum run time in seconds, after which the best solution so far will be returned.

You could also experiment with other solvers. To get advice on other solvers, you’ll need to say whether your model has integer-valued variables and whether it uses only smooth functions (or, post your model file).

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<div class="post-metadata">

**Author:** ![LealzzzZZZ](https://avatars.discourse-cdn.com/v4/letter/l/c89c15/32.png) [@LealzzzZZZ](https://discuss.ampl.com/u/LealzzzZZZ)\
**Post date:** [March 22, 2023, 4:55pm UTC](https://discuss.ampl.com/t/how-to-demonstrate-the-calculation-process-and-progress-of-the-solver-lindoglobal/443/5 "2023-03-22T16:55:23Z")

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Thank you very much for your reply!
