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smmR (version 1.0.3)

meanRecurrenceTimes: Method to get the mean recurrence times \(\mu\)

Description

Method to get the mean recurrence times \(\mu\).

Usage

meanRecurrenceTimes(x, klim = 10000)

Arguments

x

An object of S3 class smmfit or smm.

klim

Optional. The time horizon used to approximate the series in the computation of the mean sojourn times vector \(m\) (cf. meanSojournTimes function).

Value

A vector giving the mean recurrence time \((\mu_{i})_{i \in [1,\dots,s]}\).

Details

Consider a system (or a component) \(S_{ystem}\) whose possible states during its evolution in time are \(E = \{1,\dots,s\}\).

We are interested in investigating the mean recurrence times of a discrete-time semi-Markov system \(S_{ystem}\). Consequently, we suppose that the evolution in time of the system is governed by an E-state space semi-Markov chain \((Z_k)_{k \in N}\). The state of the system is given at each instant \(k \in N\) by \(Z_k\): the event \(\{Z_k = i\}\).

Let \(T = (T_{n})_{n \in N}\) denote the successive time points when state changes in \((Z_{n})_{n \in N}\) occur and let also \(J = (J_{n})_{n \in N}\) denote the successively visited states at these time points.

The mean recurrence of an arbitrary state \(j \in E\) is given by:

$$\mu_{jj} = \frac{\sum_{i \in E} \nu(i) m_{i}}{\nu(j)}$$

where \((\nu(1),\dots,\nu(s))\) is the stationary distribution of the embedded Markov chain \((J_{n})_{n \in N}\) and \(m_{i}\) is the mean sojourn time in state \(i \in E\) (see meanSojournTimes function for the computation).