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## Package umontreal.iro.lecuyer.stat

This package provides elementary tools for collecting statistics and computing confidence intervals.

See:
Description

Interface Summary
ObservationListener | Represents an object that can listen to observations broadcast by statistical probes.

Class Summary
StatProbe | The objects of this class are statistical probes or collectors, which are elementary devices for collecting statistics.
Tally | This type of statistical collector takes a sequence of real-valued observations and can return the average, the variance, a confidence interval for the theoretical mean, etc.
TallyStore | This class is a variant of `Tally` for which the individual observations are stored in a list implemented as a `DoubleArrayList`.

## Package umontreal.iro.lecuyer.stat Description

This package provides elementary tools for collecting statistics and computing confidence intervals. The base class `StatProbe` implements common methods needed by all probes. Its subclass `Tally` collects data as a sequence of observations X1, X2,..., and computes sample averages, sample standard deviations, and confidence intervals based on the normality assumption. The class `TallyStore` is similar, but it also stores the individual observations in a list implemented as a `DoubleArrayList` . This permits one to compute more quantities and to use the methods provided by COLT for computing descriptive statistics.

The class `Accumulate` computes integrals and averages with respect to time. This class is in package `simevents` because its operation depends on the simulation clock.

All classes that represent statistical probes support the observer design pattern, well-known in software engineering. This pattern facilitates the separation of data generation (by the simulation program) from data processing (for statistical reports and displays). This can be very helpful in particular in large simulation programs or libraries, where different objects may need to process the same data in different ways. A statistical probe maintains a list of registered `ObservationListener` objects, and broadcasts information to all its registered observers whenever appropriate. Any object that implements the interface `ObservationListener` can register as an observer. For an example, see the program `QueueObs` in the directory `examples`.

Subpackages of package `stat` provide matrices of `Tally`'s (see the overview on page of this guide), and lists of `Tally`'s (see page of this guide).

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To submit a bug or ask questions, send an e-mail to Pierre L'Ecuyer.