Event Handling in Differential Equations

Event detection is new to NDSolve--Mathematica's all-in-one numerical differential equation solver.

NDSolve now has a uniquely flexible framework for event detection and handling--that allows differential equations to be solved differently in different regions, with boundaries between regions determined dynamically by features of the solutions obtained.

Typical applications include:

• Modeling hybrid systems with physical constraints where the event triggers swapping between different regimes
• Solving only until some logical or functional condition is satisfied
• Continuing a solution until a key is pressed or another external event takes place
• Collecting samples of solutions at particular events, or for Poincaré sections