Documentation of integration algorithms

[Francesco Casella]

The available integration algorithms in OMC are very poorly documented. The user's guide only mentions dassl, euler and rungekutta at page 31, under the simulate command explanation. There's no mention of integration algorithms anywhere else.

OMEdit lists: dassl, euler, rungekutta, inline-euler, inline-rungekutta, dasslwort, radau1, radau3, radau5, lobatto2, lobatto4
(is the list complete?)

However, there is absolutely no documentation about which algorithm each label refers to, including whether or not the algorithm has a fixed or variable step size and order.

Please update the user's guide including this information, which is a lot more important than a detailed description of the GUI features, which are intuitive enough to be understood without a manual. I would suggest adding a specific chapter (or appendix) to this issue, as this is in common among OMEdit, OMNotebook, shell and command line interfaces.

[Lennart Ochel]

The following integration algorithms are available using the c-runtime:

stdout            | info    | detaild flag-description for: <-s=value> or <-s value>
|                 | |       | value specifies the solver
|                 | |       | | | euler              [euler]
|                 | |       | | | rungekutta         [rungekutta]
|                 | |       | | | dassl              [dassl with colored numerical jacobian, with interval root finding - default]
|                 | |       | | | inline-euler       [inline-euler]
|                 | |       | | | optimization       [optimization]
|                 | |       | | | radau5             [radau5 [sundial/kinsol needed]]
|                 | |       | | | radau3             [radau3 [sundial/kinsol needed]]
|                 | |       | | | radau1             [radau1 [sundial/kinsol needed]]
|                 | |       | | | lobatto2           [lobatto2 [sundial/kinsol needed]]
|                 | |       | | | lobatto4           [lobatto4 [sundial/kinsol needed]]
|                 | |       | | | lobatto6           [lobatto6 [sundial/kinsol needed]]
|                 | |       | | | dasslwort          [dassl without internal root finding]
|                 | |       | | | dassltest          [dassl for debug propose]
|                 | |       | | | dasslSymJac        [dassl with symbolic jacobian]
|                 | |       | | | dasslNumJac        [dassl with numerical jacobian]
|                 | |       | | | dasslColorSymJac   [dassl with colored symbolic jacobian]
|                 | |       | | | dasslInternalNumJac [dassl with internal numerical jacobian]
|                 | |       | | | inline-rungekutta  [inline-rungekutta]
|                 | |       | | | qss                [qss]

I guess, there is no more documentation than these brief lines.
@Willi, Vitalij: Please, fix the missing documentation or just comment each solver within this thread, so I can update the documentation.

[Lennart Ochel]

Replying to lochel:

@Willi, Vitalij: Please, fix the missing documentation or just comment each solver within this thread, so I can update the documentation.

*push*

[Lennart Ochel]

Is there any progress?

[Francesco Casella]

Last June, Vitalij prepared this nice document:

​https://openmodelica.org/svn/OpenModelica/trunk/doc/SimulationRuntime/IntegrationAlgorithms/IntegrationAlgorithms.pdf

(source here: ​https://openmodelica.org/svn/OpenModelica/trunk/doc/SimulationRuntime/IntegrationAlgorithms/IntegrationAlgorithms.tex).

I would suggest to put this information in an appendix of the User's Guide, and to refer to this appendix in Sections 2.5.1 and 14.1.5. I would also suggest to put a note somewhere in Section 4 (OMNotebook) referring to that appendix for the arguments of the simulation() command.

[Adeel Asghar]

r22898, r22897.
Added IntegrationAlgorithms.pdf to OpenModelica installation package.
Added an appendix in users guide which links to IntegrationAlgorithms.pdf file.
Added references to the appendix in sections 2.5.1 and 14.1.5.

[Martin Sjölund]

This ticket was not closed for 1.9.1, which has now been released. It was batch modified for milestone 1.9.2 (but maybe an empty milestone was more appropriate; feel free to change it).

[Martin Sjölund]

Milestone changed to 1.9.3 since 1.9.2 was released.

[Martin Sjölund]

Moved to new milestone 1.9.4

[Lennart Ochel]

It seems that this was fixed in the past. Please feel free to reopen this ticket if there is still something missing.