Sundials Solver¶
DEDiscover uses the CVODE solver which is part of the Sundials suite of solvers developed at the Lawrence Livermore National Laboratory, where you can find mode details about their implementation and configuration. This solver contains an option where a user can select whether the model should be considered stiff or non-stiff. Not all parameters and features used by this solver are configurable in DEDiscover. The table below shows the list of configurable parameters.
| Name | Descriptions | Constraints and Notes |
|---|---|---|
| Problem type | Stiff or non-stiff problem. | Solver will NOT switch during execution |
| Max Steps | Maximum number of steps | Must be greater than 1, defaults to 500. |
| Max # of error test failures | Defaults to 7. | |
| Max # of linear iterations | Defaults to 3. | |
| Max # of converg. failures | Defaults to 10. | |
| Safety factor | Step size control param | Between 0 and 1. Smaller values results in more steps, higher accuracy and computing costs. |
| Init Step Size | Initial step size | Must be greater than 0 |
| Min Step Size | Minimum Step Size | Must be greater than 0 and less than Max Step Size |
| Max Step Size | Maximum step Size | Must be greater than 0 and less than whole time range |
| R tolerance | Relative Error Tolerance | Decreasing this value will increase accuracy, but add to the computation time |
| A Tolerance | Absolute Error Tolerance | Decreasing this value will increase accuracy, but add to the computation time |