Constraint functions should be std::function instead of function pointers

[schulz0r]

Every example in this project has predefined constraint functions (e.g. events) where values do not change during runtime. Since I have a lot of trajectories to plan which can have arbitrary start and endpoints, I need to reset the functions every time I want to plan a new trajectory. Sadly, the problem definition struct uses C-style function pointers, which do not allow for that.

I would like to see std::function to replace the C-style pointers, so it is possible to use lambdas which capture variables (e.g. the start and stop state) from outside the function. I think this change would not even require any changes to the examples because std::functions are pretty backward compatible.
To illustrate what I want to do, see following code. The first block depicts what is possible right now:

Eigen::Matrix<adouble, 6, 1> myFinalState; // fill this vector appropriately
Prob problem;
// you can assign lambdas to function pointers btw
problem.events = [](adouble* some_args) {
    // cannot see myFinalState
    // thus cannot set it
}

With std::function, following will be possible:

Eigen::Matrix<adouble, 6, 1> myFinalState; // fill this vector appropriately
Prob problem;
// std::function allows to capture myFinalState
problem.events = [&myFinalState](adouble* some_args) {
    Eigen::Map<Eigen::Matrix<adouble, 6, 1>> eventVector(e, 6);    // wrap pointer into eigen vector
    eventVector << myFinalState;    // set final state values here
}

[vmbecerra]

Philip, Ok - let me look into this I will come back to you a.s.a.p. Best Victor.

…

On Wed, 9 Sep 2020 at 10:09, schulz0r ***@***.***> wrote: Every example in this project has predefined constraint functions (e.g. events) where values do not change during runtime. Since I have a lot of trajectories to plan which can have arbitrary start and endpoints, I need to reset the functions every time I want to plan a new trajectory. Sadly, the problem definition struct uses C-style function pointers, which do not allow for that. I would like to see std::function to replace the C-style pointers, so it is possible to use lambdas which capture variables (e.g. the start and stop state) from outside the function. I think this change would not even require any changes to the examples because std::functions are pretty backward compatible. To illustrate what I want to do, see following code. The first block depicts what is possible right now: Eigen::Matrix<adouble, 6, 1> myFinalState; // fill this vector appropriately Prob problem; // you can assign lambdas to function pointers btw problem.events = [](adouble* e, adouble* initial_states, adouble* final_states, adouble* parameters,adouble& t0, adouble& tf, adouble* xad, int iphase, Workspace* workspace) { // cannot see myFinalState // thus cannot set it } With std::function, following will be possible: Eigen::Matrix<adouble, 6, 1> myFinalState; // fill this vector appropriately Prob problem; // std::function allows to capture myFinalState problem.events = [&myFinalState](adouble* e, adouble* initial_states, adouble* final_states, adouble* parameters,adouble& t0, adouble& tf, adouble* xad, int iphase, Workspace* workspace) { Eigen::Map<Eigen::Matrix<adouble, 6, 1>> eventVector(e, 6); // wrap pointer into eigen vector eventVector << myFinalState; // set final state values here } — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#27>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADGCMBK4E7SSHF3B7DVR37TSE5A4TANCNFSM4RBT42YA> .

[schulz0r]

I received your advise to simply set the event constraint bounds:

problem.phases(1).bounds.lower.events << x0, xf;
problem.phases(1).bounds.upper.events << x0, xf;

The event function looks like the one from the Alpine Rider example.

[schulz0r]

Hello Victor, I think I figured out what is the problem with the linking. I cannot compile the new SNOPT interface thou, so I have to fix that problem first. I will report back in the next days. Philipp

…

Am 09.09.2020 um 19:50 schrieb vmbecerra ***@***.***>: Philip, Ok - let me look into this I will come back to you a.s.a.p. Best Victor. On Wed, 9 Sep 2020 at 10:09, schulz0r ***@***.***> wrote: > Every example in this project has predefined constraint functions (e.g. > events) where values do not change during runtime. Since I have a lot of > trajectories to plan which can have arbitrary start and endpoints, I need > to reset the functions every time I want to plan a new trajectory. Sadly, > the problem definition struct uses C-style function pointers, which do not > allow for that. > > I would like to see std::function to replace the C-style pointers, so it > is possible to use lambdas which capture variables (e.g. the start and stop > state) from outside the function. I think this change would not even > require any changes to the examples because std::functions are pretty > backward compatible. > To illustrate what I want to do, see following code. The first block > depicts what is possible right now: > > Eigen::Matrix<adouble, 6, 1> myFinalState; // fill this vector appropriately > Prob problem; > // you can assign lambdas to function pointers btw > problem.events = [](adouble* e, adouble* initial_states, adouble* final_states, > adouble* parameters,adouble& t0, adouble& tf, adouble* xad, > int iphase, Workspace* workspace) { > // cannot see myFinalState > // thus cannot set it > } > > With std::function, following will be possible: > > Eigen::Matrix<adouble, 6, 1> myFinalState; // fill this vector appropriately > Prob problem; > // std::function allows to capture myFinalState > problem.events = [&myFinalState](adouble* e, adouble* initial_states, adouble* final_states, > adouble* parameters,adouble& t0, adouble& tf, adouble* xad, > int iphase, Workspace* workspace) { > Eigen::Map<Eigen::Matrix<adouble, 6, 1>> eventVector(e, 6); // wrap pointer into eigen vector > eventVector << myFinalState; // set final state values here > } > > — > You are receiving this because you are subscribed to this thread. > Reply to this email directly, view it on GitHub > <#27>, or unsubscribe > <https://github.com/notifications/unsubscribe-auth/ADGCMBK4E7SSHF3B7DVR37TSE5A4TANCNFSM4RBT42YA> > . > — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#27 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AC7OZDSR3AMVPWCM34WZZXTSE6563ANCNFSM4RBT42YA>.

[vmbecerra]

Philipp Ok, many thanks. I will wait for your update. I have been updating the documentation in the meantime. Best Victor.

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On Mon, 21 Sep 2020 at 15:38, schulz0r ***@***.***> wrote: Hello Victor, I think I figured out what is the problem with the linking. I cannot compile the new SNOPT interface thou, so I have to fix that problem first. I will report back in the next days. Philipp > Am 09.09.2020 um 19:50 schrieb vmbecerra ***@***.***>: > > > Philip, > > Ok - let me look into this I will come back to you a.s.a.p. > > Best > > Victor. > > On Wed, 9 Sep 2020 at 10:09, schulz0r ***@***.***> wrote: > > > Every example in this project has predefined constraint functions (e.g. > > events) where values do not change during runtime. Since I have a lot of > > trajectories to plan which can have arbitrary start and endpoints, I need > > to reset the functions every time I want to plan a new trajectory. Sadly, > > the problem definition struct uses C-style function pointers, which do not > > allow for that. > > > > I would like to see std::function to replace the C-style pointers, so it > > is possible to use lambdas which capture variables (e.g. the start and stop > > state) from outside the function. I think this change would not even > > require any changes to the examples because std::functions are pretty > > backward compatible. > > To illustrate what I want to do, see following code. The first block > > depicts what is possible right now: > > > > Eigen::Matrix<adouble, 6, 1> myFinalState; // fill this vector appropriately > > Prob problem; > > // you can assign lambdas to function pointers btw > > problem.events = [](adouble* e, adouble* initial_states, adouble* final_states, > > adouble* parameters,adouble& t0, adouble& tf, adouble* xad, > > int iphase, Workspace* workspace) { > > // cannot see myFinalState > > // thus cannot set it > > } > > > > With std::function, following will be possible: > > > > Eigen::Matrix<adouble, 6, 1> myFinalState; // fill this vector appropriately > > Prob problem; > > // std::function allows to capture myFinalState > > problem.events = [&myFinalState](adouble* e, adouble* initial_states, adouble* final_states, > > adouble* parameters,adouble& t0, adouble& tf, adouble* xad, > > int iphase, Workspace* workspace) { > > Eigen::Map<Eigen::Matrix<adouble, 6, 1>> eventVector(e, 6); // wrap pointer into eigen vector > > eventVector << myFinalState; // set final state values here > > } > > > > — > > You are receiving this because you are subscribed to this thread. > > Reply to this email directly, view it on GitHub > > <#27>, or unsubscribe > > < https://github.com/notifications/unsubscribe-auth/ADGCMBK4E7SSHF3B7DVR37TSE5A4TANCNFSM4RBT42YA > > > . > > > — > You are receiving this because you authored the thread. > Reply to this email directly, view it on GitHub < #27 (comment)>, or unsubscribe < https://github.com/notifications/unsubscribe-auth/AC7OZDSR3AMVPWCM34WZZXTSE6563ANCNFSM4RBT42YA >. > — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#27 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADGCMBI7ULTMS6THRPSWFNLSG5QPVANCNFSM4RBT42YA> .

[schulz0r]

Good night, I couldn’t rest without having solved the problem first. The latest PR should adds some lines to the examples' CMakeLists to make them work with SNOPT. I hope this helps you to avoid manual linking. Tomorrow I will check why there are no debug symbols generated when using -DCMAKE_BUILD_TYPE=Debug, as you mentioned earlier. Philipp

…

Am 21.09.2020 um 16:47 schrieb vmbecerra ***@***.***>: Philipp Ok, many thanks. I will wait for your update. I have been updating the documentation in the meantime. Best Victor. On Mon, 21 Sep 2020 at 15:38, schulz0r ***@***.***> wrote: > Hello Victor, > I think I figured out what is the problem with the linking. I cannot > compile the new SNOPT interface thou, so I have to fix that problem first. > I will report back in the next days. > > Philipp > > > Am 09.09.2020 um 19:50 schrieb vmbecerra ***@***.***>: > > > > > > Philip, > > > > Ok - let me look into this I will come back to you a.s.a.p. > > > > Best > > > > Victor. > > > > On Wed, 9 Sep 2020 at 10:09, schulz0r ***@***.***> wrote: > > > > > Every example in this project has predefined constraint functions (e.g. > > > events) where values do not change during runtime. Since I have a lot > of > > > trajectories to plan which can have arbitrary start and endpoints, I > need > > > to reset the functions every time I want to plan a new trajectory. > Sadly, > > > the problem definition struct uses C-style function pointers, which do > not > > > allow for that. > > > > > > I would like to see std::function to replace the C-style pointers, so > it > > > is possible to use lambdas which capture variables (e.g. the start and > stop > > > state) from outside the function. I think this change would not even > > > require any changes to the examples because std::functions are pretty > > > backward compatible. > > > To illustrate what I want to do, see following code. The first block > > > depicts what is possible right now: > > > > > > Eigen::Matrix<adouble, 6, 1> myFinalState; // fill this vector > appropriately > > > Prob problem; > > > // you can assign lambdas to function pointers btw > > > problem.events = [](adouble* e, adouble* initial_states, adouble* > final_states, > > > adouble* parameters,adouble& t0, adouble& tf, adouble* xad, > > > int iphase, Workspace* workspace) { > > > // cannot see myFinalState > > > // thus cannot set it > > > } > > > > > > With std::function, following will be possible: > > > > > > Eigen::Matrix<adouble, 6, 1> myFinalState; // fill this vector > appropriately > > > Prob problem; > > > // std::function allows to capture myFinalState > > > problem.events = [&myFinalState](adouble* e, adouble* initial_states, > adouble* final_states, > > > adouble* parameters,adouble& t0, adouble& tf, adouble* xad, > > > int iphase, Workspace* workspace) { > > > Eigen::Map<Eigen::Matrix<adouble, 6, 1>> eventVector(e, 6); // wrap > pointer into eigen vector > > > eventVector << myFinalState; // set final state values here > > > } > > > > > > — > > > You are receiving this because you are subscribed to this thread. > > > Reply to this email directly, view it on GitHub > > > <#27>, or unsubscribe > > > < > https://github.com/notifications/unsubscribe-auth/ADGCMBK4E7SSHF3B7DVR37TSE5A4TANCNFSM4RBT42YA > > > > > . > > > > > — > > You are receiving this because you authored the thread. > > Reply to this email directly, view it on GitHub < > #27 (comment)>, or > unsubscribe < > https://github.com/notifications/unsubscribe-auth/AC7OZDSR3AMVPWCM34WZZXTSE6563ANCNFSM4RBT42YA > >. > > > > — > You are receiving this because you commented. > Reply to this email directly, view it on GitHub > <#27 (comment)>, or > unsubscribe > <https://github.com/notifications/unsubscribe-auth/ADGCMBI7ULTMS6THRPSWFNLSG5QPVANCNFSM4RBT42YA> > . > — You are receiving this because you modified the open/close state. Reply to this email directly, view it on GitHub <#27 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AC7OZDWEK7J54PQ6A5OIYADSG5RQ3ANCNFSM4RBT42YA>.

[vmbecerra]

Philip Excellent, many thanks for that. I have now merged your pull request. Best Victor.

…

On Mon, 21 Sep 2020 at 23:24, schulz0r ***@***.***> wrote: Good night, I couldn’t rest without having solved the problem first. The latest PR should adds some lines to the examples' CMakeLists to make them work with SNOPT. I hope this helps you to avoid manual linking. Tomorrow I will check why there are no debug symbols generated when using -DCMAKE_BUILD_TYPE=Debug, as you mentioned earlier. Philipp > Am 21.09.2020 um 16:47 schrieb vmbecerra ***@***.***>: > > > Philipp > > Ok, many thanks. I will wait for your update. I have been updating the > documentation in the meantime. > > Best > > Victor. > > On Mon, 21 Sep 2020 at 15:38, schulz0r ***@***.***> wrote: > > > Hello Victor, > > I think I figured out what is the problem with the linking. I cannot > > compile the new SNOPT interface thou, so I have to fix that problem first. > > I will report back in the next days. > > > > Philipp > > > > > Am 09.09.2020 um 19:50 schrieb vmbecerra ***@***.***>: > > > > > > > > > Philip, > > > > > > Ok - let me look into this I will come back to you a.s.a.p. > > > > > > Best > > > > > > Victor. > > > > > > On Wed, 9 Sep 2020 at 10:09, schulz0r ***@***.***> wrote: > > > > > > > Every example in this project has predefined constraint functions (e.g. > > > > events) where values do not change during runtime. Since I have a lot > > of > > > > trajectories to plan which can have arbitrary start and endpoints, I > > need > > > > to reset the functions every time I want to plan a new trajectory. > > Sadly, > > > > the problem definition struct uses C-style function pointers, which do > > not > > > > allow for that. > > > > > > > > I would like to see std::function to replace the C-style pointers, so > > it > > > > is possible to use lambdas which capture variables (e.g. the start and > > stop > > > > state) from outside the function. I think this change would not even > > > > require any changes to the examples because std::functions are pretty > > > > backward compatible. > > > > To illustrate what I want to do, see following code. The first block > > > > depicts what is possible right now: > > > > > > > > Eigen::Matrix<adouble, 6, 1> myFinalState; // fill this vector > > appropriately > > > > Prob problem; > > > > // you can assign lambdas to function pointers btw > > > > problem.events = [](adouble* e, adouble* initial_states, adouble* > > final_states, > > > > adouble* parameters,adouble& t0, adouble& tf, adouble* xad, > > > > int iphase, Workspace* workspace) { > > > > // cannot see myFinalState > > > > // thus cannot set it > > > > } > > > > > > > > With std::function, following will be possible: > > > > > > > > Eigen::Matrix<adouble, 6, 1> myFinalState; // fill this vector > > appropriately > > > > Prob problem; > > > > // std::function allows to capture myFinalState > > > > problem.events = [&myFinalState](adouble* e, adouble* initial_states, > > adouble* final_states, > > > > adouble* parameters,adouble& t0, adouble& tf, adouble* xad, > > > > int iphase, Workspace* workspace) { > > > > Eigen::Map<Eigen::Matrix<adouble, 6, 1>> eventVector(e, 6); // wrap > > pointer into eigen vector > > > > eventVector << myFinalState; // set final state values here > > > > } > > > > > > > > — > > > > You are receiving this because you are subscribed to this thread. > > > > Reply to this email directly, view it on GitHub > > > > <#27>, or unsubscribe > > > > < > > https://github.com/notifications/unsubscribe-auth/ADGCMBK4E7SSHF3B7DVR37TSE5A4TANCNFSM4RBT42YA > > > > > > > . > > > > > > > — > > > You are receiving this because you authored the thread. > > > Reply to this email directly, view it on GitHub < > > #27 (comment)>, or > > unsubscribe < > > https://github.com/notifications/unsubscribe-auth/AC7OZDSR3AMVPWCM34WZZXTSE6563ANCNFSM4RBT42YA > > >. > > > > > > > — > > You are receiving this because you commented. > > Reply to this email directly, view it on GitHub > > <#27 (comment)>, or > > unsubscribe > > < https://github.com/notifications/unsubscribe-auth/ADGCMBI7ULTMS6THRPSWFNLSG5QPVANCNFSM4RBT42YA > > > . > > > — > You are receiving this because you modified the open/close state. > Reply to this email directly, view it on GitHub < #27 (comment)>, or unsubscribe < https://github.com/notifications/unsubscribe-auth/AC7OZDWEK7J54PQ6A5OIYADSG5RQ3ANCNFSM4RBT42YA >. > — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#27 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADGCMBJGG4MCZKBKWHMXXCDSG7HATANCNFSM4RBT42YA> .