HourlyToDaily-function that obtain daily data from hourly data

HourlyToDaily

HourlyToDaily <- function(data.x, ncol.obs, ncol.date, na.presence = TRUE, value = "mean") {
  #
  if (!any(value == c("mean", "accumulated"))) {
    stop(" value must to be 'mean' or 'accumulated'")
  }
  # Calculate the mean of the variable of interest
  first.year <- min(data.x$year, na.rm = na.presence)
  last.year  <- max(data.x$year, na.rm = na.presence)
  x.daily.per.years <- list()
  date.tot <- list()
  c = 1
  #  Creates a temporary i data.frame for each year == i
  for (i in first.year:last.year) {
    x.anual <- data.x[data.x$year == i, ]
    # It takes the i year df and creates a j df for each month == j
    first.month = min(x.anual$month, na.rm = na.presence)
    last.month  = max(x.anual$month, na.rm = na.presence)
    x.daily.per.month <- list()
    date.list <- list()
    for (j in first.month:last.month) {
      x.month <- x.anual[x.anual$month == j, ]
      # It takes the j month df and creates a k df for each day == k
      first.day = min(x.month$day, na.rm = na.presence)
      last.day  = max(x.month$day, na.rm = na.presence)
      x.value.max <- list()
      x.value.min <- list()
      x.value <- list()
      date.x <- list()
      for (k in first.day:last.day) {
        x.day <- x.month[x.month$day == k, ]
        # Calculates the mean value or the accumulated value
        if (all(unlist(lapply(X = x.day[ , ncol.obs], FUN = is.na)))) {
          x.value[k] <- NA
        } else {
          if (value == "mean") {
            x.value.max[k] <- max(x.day[ , ncol.obs], na.rm = na.presence)
            x.value.min[k] <- min(x.day[ , ncol.obs], na.rm = na.presence)
            x.value[k] <- mean(x = c(x.value.max[[k]], x.value.min[[k]]), na.rm = na.presence)
          } else {
            x.value[k] <- sum(x.day[ , ncol.obs], na.rm = na.presence)
          }
        }
        date.x[k] <- x.day[ , ncol.date][1] 
      } # end cycle day
      x.daily.per.month[[j]] <- unlist(x.value)
      date.list[[j]]         <- date.x     
    } # end cycle month
    x.daily.per.years[[c]] <- unlist(x.daily.per.month)
    date.tot[[c]]          <- unlist(date.list)    
    c = c + 1
    daily.data <- as.data.frame(unlist(x.daily.per.years))
    daily.data <- cbind.data.frame(unlist(date.tot), daily.data)
    colnames(daily.data) <- c("date", "value")
    daily.data$date <- as.Date.numeric(daily.data$date, origin = "1970-01-01")
  }
  return(daily.data)
}