cleanEventTimes {deSolve}R Documentation

Find Nearest Event for Each Time Step and Clean Time Steps to Avoid Doubles


These functions can be used for checking time steps and events used by ode solver functions. They are normally called internally within the solvers.


nearestEvent(times, eventtimes)
cleanEventTimes(times, eventtimes, eps = .Machine$double.eps * 10)



the vector of output times,


a vector with the event times,


relative tolerance value below which two numbers are assumed to be numerically equal.


In floating point arithmetics, problems can occur if values have to be compared for 'equality' but are only close to each other and not exactly the same.

The utility functions can be used to add all eventtimes to the output times vector, but without including times that are very close to an event.

This means that all values of eventtimes are contained but only the subset of times that have no close neighbors in eventtimes.

These checks are normally performed internally by the integration solvers.


nearestEvent returns a vector with the closest events for each time step and

cleanEventTimes returns a vector with the output times without all those that are 'very close' to an event.


Thomas Petzoldt

See Also



events <- sort(c(0, 2, 3, 4 + 1e-10, 5, 7 - 1e-10,
                 7 + 6e-15, 7.5, 9, 24.9999, 25, 80, 1001, 1e300))
times  <- sort(c(0, 1:7, 4.5, 6.75, 7.5, 9.2, 9.0001, 25, 879, 1e3, 1e300+5))

nearest <- nearestEvent(times, events)
data.frame(times=times, nearest = nearest)

## typical usage: include all events in times after removing values that
## are numerically close together, events have priority 
unique_times <- cleanEventTimes(times, events)
newtimes <- sort(c(unique_times, events))

[Package deSolve version 1.28 Index]