Fits a straight line to a vector of values using lm(), and uses the regression coefficients to subtract off the linear trend from the values.
detrendHeight(pt)
Arguments
| pt | A vector of numeric values to be detrended |
|---|
Value
A list containing the following:
pt A vector of detrended values
seg_len The segment length used
h The mean height of the water column
trend A two element vector of the intercept and slope
from the linear regression.
Details
Typically this is used to remove a tidal trend from a ocean surface height time series before attempting to calculate statistics for waves, which are variations above and below the mean surface height. Returns a series of residuals around the linear trend, in the original units of measurement (typically meters).
Examples
data(wavedata) detrended <- detrendHeight(wavedata$swDepth.m) pt <- detrended[['pt']] plot(pt, type = 'l')
