Converts a 2D spectrum time series to a 1D spectrum

Usage

convert_spectrum_2d1d(spec, ...)

Arguments

spec: a structure with the needed fields, as an output from 'get_2Dspectrum' for example
...: unused yet

Value

a structure comparable to 'get_1Dspectrum'.

Examples

# Ensure that data package is available before running the example.
#  If it is not, see the `resourcecode` package vignette for details
# on installing the required data package.
if (requireNamespace("resourcecodedata", quietly = TRUE)) {
  spec <- resourcecodedata::rscd_2d_spectra
  spec1D_RSCD <- resourcecodedata::rscd_1d_spectra
  spec1D <- convert_spectrum_2d1d(spec)
  # Check the differences, should be low
  max(abs(spec1D_RSCD$ef - spec1D$ef))

  # Plot the different spectrum
  plot(spec1D$freq, spec1D$ef[, 1], type = "l", log = "xy")
  lines(spec1D_RSCD$freq, spec1D_RSCD$ef[, 1], col = "red")

  # Images
  lims <- c(0, 360)
  r <- as.POSIXct(round(range(spec1D$forcings$time), "hours"))
  oldpar <- par(mfcol = c(2, 1))
  image(spec1D$forcings$time, spec1D$freq, t(spec1D$th1m),
    zlim = lims,
    xlab = "Time",
    ylab = "Freq (Hz)",
    xaxt = "n",
    main = "Directionnal spreading"
  )
  axis.POSIXct(1, spec1D$forcings$time,
    at = seq(r[1], r[2], by = "week"),
    format = "%Y-%m-%d",
    las = 2
  )
  image(spec1D_RSCD$forcings$time, spec1D_RSCD$freq, t(spec1D_RSCD$th1m),
    zlim = lims,
    xlab = "Time",
    ylab = "Freq (Hz)",
    xaxt = "n"
  )
  axis.POSIXct(1, spec1D$forcings$time,
    at = seq(r[1], r[2], by = "week"),
    format = "%Y-%m-%d",
    las = 2
  )
  par(oldpar)
}