simp.emd {DecomposeR}

Simplifies the components of an EMD

Description

Simplifies the component of an EMD to only extremas and zero-crossings, and outputs problematic extrema: multiple extrema (extrema not separated by zero-crossings) and crossing extrema (extrema at zero).

Usage

simp.emd(emd = NULL, m = NULL, dt = NULL, repl = 1, use.names = FALSE)

Arguments

emd

emd-type object

m

a matrix of the amplitude values (xy) of the components, each column being a component. Each column should have the same number of non NA values. Vectors, for 1 component, are accepted. Is overridden by emd.

dt

the depth or time value. Is overridden by emd.

repl

the amount of replicates in m. Is overridden by emd.

use.names

whether to use the column names to identify problematic extrema

Value

a list of the depth or time values ($dt) of the simplified IMF (Intrinsic Mode Function), of their amplitude ($xy), and of the position and component of problematic multiple extrema ($multiple_extrema) and crossing extrema ($crossing_extrema)

Examples

xytest <- c(0.5, 1,-1,-0.85,-0.5,-1,-0.5,-1,1,0.5,0,0,
            1,-1,0,1,2,-2,1,2,1,3,0,-1,-1,3,0)

repeatafterme <- 2

m  <- matrix(rep(xytest,repeatafterme), ncol = repeatafterme)
dt <- 1:length(xytest)

res <- simp.emd(m = m, dt = dt, repl = repeatafterme)

opar <- par("mfrow")

par(mfrow = c(1,1))

plot(dt, xytest, type = "o", pch = 19)
abline(h = 0, col = "grey")

me <- res$multiple_extrema$dt[res$multiple_extrema$repl == 1]
ce <- res$crossing_extrema$dt[res$multiple_extrema$repl == 1]

abline(v = me, col = "orange")
abline(v = ce, col = "darkred")

points(res$dt[,1], res$xy[,1], col = "red", pch = 19)

par(mfrow = opar)