PhytoSim Simulation

Price: 699 EUR, excl. VAT (free 30-day trial available)

The Simulation module allows you to **simulate dynamic models** written using the Modelling module. Simulation results can be directly visualized using graphs and/or compared to external data (loaded in the Data I/O module). Simulation results will also be available in the Data I/O module for further processing e.g. output to files.

### Why you will like this module:

- Compilation free modelling: Immediately see the results of model changes.
- Automatic unit conversions: Differences between model and input data units are automatically resolved.
- Drag and drop simulation result visualisation: Simply drag a model component onto a graph to visualize it.

More details in the Simulation User Guide.

### Built-in solvers:

For **algebraic equation models** (no differential equations):

- Algebraic solver: The model is evaluated at fixed steps of the independent variable.

For **differential equation models** (differential and algebraic equations):

- 4th order variable step size: An adaptive step size Runge-Kutta solver which bases its next step on four trial steps at the current independent variable value. The step that is taken is as large as the user defined accuracy of the results permits it to be. See http://en.wikipedia.org/wiki/Runge-Kutta_methods for more detailed information.
- 4th order fixed step size: A fixed step size Runge-Kutta solver which uses four trial steps at the current independent variable value to reach a better accuracy than when one large step (with the user defined step size) would be taken. See http://en.wikipedia.org/wiki/Runge-Kutta_methods for more detailed information.
- Euler: Most simple differential equation solver. Use this for testing purposes only. If a fixed step size solver is required, use the 4th order one. That one is more accurate. See http://en.wikipedia.org/wiki/Euler_integration for more information on the Euler method.
- CVODE: Variable step size solver which is part of the Lawrence Livermore National Laboratory SUNDIALS solver suite. This solver is also suited for solving stiff differential equation systems.

### Dependencies (modules required by this module):

PhytoSim Data I/O

PhytoSim Modelling