stream (version 1.5-1)

DSC_Window: A sliding window from a Data Stream

Description

Interface for DSO_Window. Represents the points in the sliding window as micro-clusters.

Usage

DSC_Window(horizon = 100, lambda = 0)

Value

An object of class DSC_Window (subclass of DSC, DSC_R, DSC_Micro).

Arguments

horizon

the window length.

lambda

decay factor damped window model. lambda=0 means no dampening.

Author

Michael Hahsler

Details

If lambda is greater than 0 then the weight uses a damped window model (Zhu and Shasha, 2002). The weight for points in the window follows \(2^{-lambda*t}\) where \(t\) is the age of the point.

References

Zhu, Y. and Shasha, D. (2002). StatStream: Statistical Monitoring of Thousands of Data Streams in Real Time, International Conference of Very Large Data Bases (VLDB'02).

See Also

DSC, DSC_Micro

Examples

stream <- DSD_Gaussians(k=3, d=2, noise=0.05)

window <- DSC_Window(horizon=100)
window

update(window, stream, 200)
window

# plot micro-clusters
plot(window, stream)

# animation for a window using a damped window model. The weight decays
# with a half-life of 25
if (FALSE) {
window <- DSC_Window(horizon=25, lambda=1/25)
animate_cluster(window, stream, horizon=1, n=100, xlim=c(0,1), ylim=c(0,1))
}