n.extrema: Number of extrema/zero-crossings

In DecomposeR: Empirical Mode Decomposition for Cyclostratigraphy

Number of extrema/zero-crossings

Description

Computes the number of extrema and zero-crossings for different groups of data, by their id or separated by NA values

Usage

n.extrema(
  xy,
  id = NULL,
  use.names = TRUE,
  bound = FALSE,
  local = FALSE,
  zc = TRUE
)

Arguments

xy	signal or decomposed signal
id	the id for different groups. If any NA value is in xy, it will also separate two groups of data
use.names	whether to use the names in id
bound, local, zc	parameters to feed to extremist

Value

a list of the number of minima ($n.min), maxima ($n.max), and, if zc = TRUE, zero-crossings ($n.cross)

Examples

set.seed(42)

n <- 600
t <- seq_len(n)

p1 <- 30
p2 <- 240

xy <- (1 + 0.6 * sin(t*2*pi/p2)) * sin(t*2*pi/p1)  + 2 * sin(t*2*pi/p2) +
  rnorm(n, sd = 0.5)

xy <- xy - mean(xy)

inter_dt <- round(runif(length(xy), min = 0.5, max = 1.5),1)

dt <- cumsum(inter_dt)

dec <- extricate(xy, dt, nimf = 7, sifting = 10,
                repl = 1, comb = 40, factor_noise = 10,
                speak = TRUE)

integrity(xy, dec)
parsimony(dec)

n.extrema(dec$m, dec$mode)

plot_emd(dec, select = c(6,8,9), pdf = FALSE, adapt.axis = TRUE)
## Not run: 
plot_emd(dec, li = list(v = 0), adapt.axis = TRUE, dir = tempdir())
## End(Not run)

DecomposeR documentation built on Feb. 16, 2023, 9:50 p.m.