WhenEvent[event, action] specifies an action that occurs when the event triggers it for equations in NDSolve.

Differential equations with actions at discrete events are used to model piecewise differential equations with jump discontinuities, or impacts and collisions such as a ...

DiscreteVariables is an option for NDSolve and other functions that specifies variables that only change at discrete times in a temporal integration.

Mathematica provides a general mechanism for specifying constraints on patterns. All you need to do is to put /;condition at the end of a pattern to signify that it applies ...

patt /; test is a pattern which matches only if the evaluation of test yields True. lhs :> rhs /; test represents a rule which applies only if the evaluation of test yields ...

DependentVariables is an option for NDSolve and other functions that specifies the list of all objects that should be considered as dependent variables in equations that have ...

Automatically selecting between hundreds of powerful and in many cases original algorithms, Mathematica provides both numerical and symbolic solving of differential equations ...

Differential equations alone are very effective for modeling continuous behavior of systems. However, many real systems involve components that change at discrete times, ...

One of the unique strengths of Mathematica's core language is its powerful and succinct—yet highly readable—symbolic pattern language. Convenient both for immediate use in ...

At the core of Mathematica's symbolic programming paradigm is the concept of transformation rules for arbitrary symbolic patterns. Mathematica's pattern language conveniently ...