Hey everyone, this is really helpful. Thanks for the info! June
On Fri, Jun 21, 2024 at 3:11 PM chao peng <[email protected]> wrote: > Hi, > > Just complemented another point. You might also need to Gather and Scatter > the acceleration and Lagrange multipliers if you want to recover the system > state exactly as the snapshot investigated. > > Something like: > > auto state_der2 = > chrono_types::make_shared<ChStateDelta>(system.GetNumCoordsVelLevel(), > &system); > system.StateGatherAcceleration(*state_der2); > > auto state_L = > chrono_types::make_shared<ChVectorDynamic<>>(system.GetNumConstraints()); > system.StateGatherReactions(*state_L); > > and similarly for the Scattering (i.e. loading back into ChSystem). > > The complete state of a system includes: X (position and orientation), V > (velocity), A (acceleration), T (time), L( Lagrange multipliers). > > Good luck. > Chao PENG. > > 在2024年6月20日星期四 UTC+2 23:24:31<[email protected]> 写道： > > BTW, if you just want to load/save the state of the system, without the > model itself, you can come up with some easier yet not complete, solution > of using ChSystem::StateGather and ChSystem::StateScatter. > > Something like: > > auto state = > chrono_types::make_shared<ChState>(system.GetNumCoordsPosLevel(), &system); > auto state_der = > chrono_types::make_shared<ChStateDelta>(system.GetNumCoordsVelLevel(), > &system); > double time; > system.StateGather(*state , *state_der, time_dummy); > > > and similarly for the Scattering (i.e. loading back into ChSystem) > > Please notice however that you have to make sure that the model is exactly > the same and also that can be additional relevant variables (e.g. some > variable in the timesteppers) that is not retrieved in this way thus making > a slight difference when you load back the state. > > > Il giorno giovedì 20 giugno 2024 alle 23:18:46 UTC+2 Dario Mangoni ha > scritto: > > Hi, > yes there is. > > You may find more references by searching for the "archive" keyword > instead of serialization. > *demo_CH_archive > <https://github.com/projectchrono/chrono/blob/main/src/demos/core/demo_CH_archive.cpp>*is > a starting point, but it's probably showing many more features that just > simply a Chrono system serialization. > *utest_CH_archive > <https://github.com/projectchrono/chrono/blob/main/src/tests/unit_tests/core/utest_CH_archive.cpp>*is > another source of information, while it's meant for testing. > > In general you can import|export to JSON, XML and binary format. > > In general, for a whole ChSystem, you can simply do something like. > > { > ChSystemNSC system; > ADD THINGS TO YOUR SYSTEM > std::ofstream mfileo("ChArchiveJSON_Pendulum.json"); > ChArchiveOutJSON archive_out(mfileo); > archive_out << CHNVP(system); > } > > std::ifstream mfilei("ChArchiveJSON_Pendulum.json"); > ChArchiveInJSON archive_in(mfilei); > > ChSystemNSC system; > archive_in >> CHNVP(system); > > Please mind that not all the classes are enabled to serialization (e.g. > ChVisualShapeFEA are not). > You may be able to check which are enabled by checking the relative > ArchiveIn|ArchiveOut methods for each class. > > Il giorno giovedì 20 giugno 2024 alle 20:00:49 UTC+2 [email protected] > ha scritto: > > Is there any way to serialize Chrono::Systems so that the system state is > recoverable from disk? I'd like to be able to save the state of the system > for debugging at a later date. > > -- > You received this message because you are subscribed to the Google Groups > "ProjectChrono" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/projectchrono/ee47e377-6e3b-4f00-9f74-23acb85fff90n%40googlegroups.com > <https://groups.google.com/d/msgid/projectchrono/ee47e377-6e3b-4f00-9f74-23acb85fff90n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "ProjectChrono" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/projectchrono/CAC1ZH50eK11ug-r%2BFn0%2B64v88eNze_f0pCfkESaqmt30HdrZ3g%40mail.gmail.com.
