ecg: Electrocardiogram data

In ade4: Analysis of Ecological Data : Exploratory and Euclidean Methods in Environmental Sciences

Description

These data were measured during the normal sinus rhythm of a patient who occasionally experiences arrhythmia. There are 2048 observations measured in units of millivolts and collected at a rate of 180 samples per second. This time series is a good candidate for a multiresolution analysis because its components are on different scales. For example, the large scale (low frequency) fluctuations, known as baseline drift, are due to the patient respiration, while the prominent short scale (high frequency) intermittent fluctuations between 3 and 4 seconds are evidently due to patient movement. Heart rhythm determines most of the remaining features in the series. The large spikes occurring about 0.7 seconds apart the R waves of normal heart rhythm; the smaller, but sharp peak coming just prior to an R wave is known as a P wave; and the broader peak that comes after a R wave is a T wave.

Usage

data(ecg)

Format

A vector of class ts containing 2048 observations.

Source

Gust Bardy and Per Reinhall, University of Washington

References

Percival, D. B., and Walden, A.T. (2000) Wavelet Methods for Time Series Analysis, Cambridge University Press.

Examples

## Not run: 
# figure 130 in Percival and Walden (2000)
if (requireNamespace("waveslim") == TRUE) { 
data(ecg)
ecg.level <- haar2level(ecg)
ecg.haar <- orthobasis.haar(length(ecg))
ecg.mld <- mld(ecg, ecg.haar, ecg.level, plot = FALSE)
res <- cbind.data.frame(apply(ecg.mld[,1:5],1,sum), ecg.mld[,6:11])
par(mfrow = c(8,1))
par(mar = c(2, 5, 1.5, 0.6))
plot(as.ts(ecg), ylab = "ECG")
apply(res, 2, function(x) plot(as.ts(x), ylim = range(res),
 ylab = ""))
par(mfrow = c(1,1))
}
## End(Not run)

Example output

Loading required namespace: waveslim

ade4 documentation built on May 2, 2019, 5:50 p.m.