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Stochastic System Definition

2020-05-18
2020-05-19
  • Maria Inês Cravo

    Has anyone used Matcont to analyse stochastic differential equations?

    I'd like to create a system with a stochastic process defined as a vector, so that the integrator can optimize the time step and use an interpolated version of the stochastic process. I did this with an Ornstein-Uhlenbeck process (a vector of white noise convoluted with a low-pass filter) and ode45 in Matlab, but in Matcont it seems that I can't use vectors in the system definition. Is there a way around this?

    The only way seems to be to define the differential equation of an Ornstein-Uhlenbeck process explicitly (X'=-X+randn) but that makes the simulation too heavy, because it uses a very small time step.

    A simple system with a stochastic process vector is shown below, with the error I get when I click "OK". Any help would be much appreciated! Thanks in advance!

     
    • hilmeijer

      hilmeijer - 2020-05-18

      Dear Maria,

      MatCont is intended for deterministic systems only. A good bifurcation theory for SDEs, and the numerical treatment, is not in the scope of this project.

      Best, Hil


      From: "Maria Inês Cravo" mariaines@users.sourceforge.net
      Sent: Monday, May 18, 2020 5:13 PM
      To: [matcont:discussion]
      Subject: [matcont:discussion] Stochastic System Definition

      Has anyone used Matcont to analyse stochastic differential equations?

      I'd like to create a system with a stochastic process defined as a vector, so that the integrator can optimize the time step and use an interpolated version of the stochastic process. I did this with an Ornstein-Uhlenbeck process (a vector of white noise convoluted with a low-pass filter) and ode45 in Matlab, but in Matcont it seems that I can't use vectors in the system definition. Is there a way around this?

      The only way seems to be to define the differential equation of an Ornstein-Uhlenbeck process explicitly (X'=-X+randn) but that makes the simulation too heavy, because it uses a very small time step.

      A simple system with a stochastic process vector is shown below, with the error I get when I click "OK". Any help would be much appreciated! Thanks in advance!


      Stochastic System Definition


      Sent from sourceforge.net because you indicated interest in https://sourceforge.net/p/matcont/discussion/762214/

      To unsubscribe from further messages, please visit https://sourceforge.net/auth/subscriptions/

       
  • Maria Inês Cravo

    Thank you so much for your quick answer! Is there any other bifurcation analysis software that supports SDEs? Maybe AUTO?

     
    • hilmeijer

      hilmeijer - 2020-05-19

      xppaut has an option to simulate stochastic ODEs, but I am not aware it supports bifurcation analysis for SDEs.


      From: "Maria Inês Cravo" mariaines@users.sourceforge.net
      Sent: Monday, May 18, 2020 9:10 PM
      To: [matcont:discussion]
      Subject: [matcont:discussion] Stochastic System Definition

      Thank you so much for your quick answer! Is there any other bifurcation analysis software that supports SDEs? Maybe AUTO?


      Stochastic System Definition


      Sent from sourceforge.net because you indicated interest in https://sourceforge.net/p/matcont/discussion/762214/

      To unsubscribe from further messages, please visit https://sourceforge.net/auth/subscriptions/

       

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