Saving ts objects as csv files

Occasionally R might not be the tool you want to use (hard to believe, but apparently that happens). Then you may need to export some data from R via a csv file. When the data is stored as a ts object, the time index can easily get lost. So I wrote a little function to make this easier, using the tsibble package to do most of the work in looking after the time index.

# Convert time series data to csv
ts2csv <- function(x) {
  fname <- paste0(deparse(substitute(x)), ".csv")
  if (NCOL(x) == 1L) {
    # Univariate time series
    readr::write_csv(
      as.data.frame(tsibble::as_tsibble(x)),
      fname)
  } else {
    # Multivariate time series
    readr::write_csv(
      as.data.frame(tsibble::spread(tsibble::as_tsibble(x), key, value)),
      fname)
  }
}

library(fpp2)
ts2csv(auscafe)    # Univariate monthly data
ts2csv(visnights)  # Multivariate quarterly data
ts2csv(elecdemand) # Multivariate half-hourly data