roughness {seewave}

Roughness or total curvature

Description

This function computes the roughness or total curvature of a curve, i.e. of a time wave or of a spectrum

Usage

roughness(x, std = FALSE)

Arguments

x

a vector

std

a logical, if set to TRUE then x is standardized by its maximum.

Details

Roughness or total curvature is the integrated squared second derivative :

roughness = \int [D^2x(t)]^2 \, \mathrm{d} t

.

Value

A vector of length 1.

Note

The value has not unit.

Author(s)

Jerome Sueur

References

Ramsay JO, Silverman BW (2005) Functional data analysis. Springer, Berlin.

See Also

rugo, rms, sh, th, H.

Examples

data(tico)
spec <- meanspec(tico, plot=FALSE)[,2]
roughness(spec)