API DocumentationΒΆ

A system in a BlockDiagram needs to provide the following attributes:

  • dim_state : the dimension of the state
  • dim_input : the dimension of the input
  • dim_output : the dimension of the output
  • output_equation_function : A callable returning the system output.

If dim_state=0, then output_equation_function recieves the current time and input as arguments during integration. If dim_state>0 then state_equation_function, taking the current time, state, and input and returning the state derivative, must also be provided. In this case, output_equation_function recieves the current time and state as arguments during integration.

If event_equation_function and update_equation_function are provided, discontinuities at zero-crossing of event_equation_function are handled. The argument rules for event_equation_function and update_equation_function during integration are the same as for output_equation_function and state_equation_function, respectively. Generally, update_equation_function is used to change what state_equation_function, output_equation_function, and event_equation_function compute based on the occurance of the discontinuity. If dim_state>0, update_equation_function must return the state immediately after the discontinuity.

The base system class takes a convenience input argument, dt. Passing dt>0 will determine the sample rate that the outputs and state are computed; dt=0 is treated as a continuous-time system. In hybrid-time BlockDiagrams, the system is automatically integrated piecewise to improve accuracy.

Future versions of SimuPy may support passing jacobian functions to ode solvers if all systems in the BlockDiagram provide the appropriate necessary jacobian functions.

A quick overview of the of the modules:

block_diagram (docstrings)
implements the BlockDiagram class to simulate interconnected systems.
systems (docstrings)
provides a few base classes for purely numerical based systems.
utils (docstrings)
provides utility functions, such as manipulating (numeric) systems and simulation results.
systems.symbolic (docstrings) and discontinuities (docstrings)
provides niceties for using symbolic expressions to define systems.
array (docstrings) and matrices (docstrings)
provide helper functions and classes for manipulating symbolic arrays, matrices, and their systems.
utils.symbolic (docstrings)
provides utility symbolic functions, such as manipulating symbolic systems.