R function for creating a regular and continuous zoo object from two vectors of dates/datetimes and values with optional fill values

zoo_regular.R

zoo.regular <- function(dates, values, by="hour", fill=NA) {
  # convert time series to regular zoo object
  require(zoo)
  z <- zoo(values, dates)
  z <- merge(z, zoo(, seq(floor_date(start(z), 'day'),
                          ceiling_date(end(z), 'day'),
                          by)), 
             fill=fill)
  z <- z[1:(length(z)-1)]
  return(z)
}