R/ArFunction.R

In detrendeR: A Graphical User Interface (GUI) to Visualize and Analyze Dendrochronological Data

ArFunction <- function(rwl, order.max = 10) {
  ar.fun <- function(rw, order.max = 10) {
    out <- c(rep(NA, order.max + 1))
    y2 <- na.omit(rw)
    ar1 <- ar(y2, order.max = order.max)
    out[1] <- ar1$order
    if (out[1] > 0) {
      for (i in 1:out[1]) {
        out[i + 1] <- ar1$ar[i]
      }
    }
    out
  }

  out <- t(apply(rwl, 2, ar.fun, order.max = order.max))
  out <- round(out, 3)
  out[, 1] <- round(out[, 1], 0)

  colnames(out) <- c("AR", paste("   t", 1:order.max, sep = ""))
  rownames(out) <- format(rownames(out), width = 9)

  cat(rep("=", (21 + order.max * 8)),
    "\n\nAUTOREGRESSIVE MODELING\n",
    rep("=", (21 + order.max * 8)),
    "\n",
    sep = ""
  )
  WriteMatrix(out,
    ID.name = "Seq",
    row.name = "Series",
    col.width = 7
  )
  cat(rep("=", (21 + order.max * 8)), "\n", sep = "")
}