n.extrema {DecomposeR}

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)