undifference seasonally (and non seasonally) differenced data

undifference.R

raw <- read.csv("https://raw.githubusercontent.com/thistleknot/Python-Stock/master/data/combined_set.csv",row.names=1,header=TRUE)


nv_diff_sets <- function(var_of_int,dataset,f_casts)
{

  s_=sndif_[which(colnames(raw)==var_of_int)]
  d_=ndif_[which(colnames(raw)==var_of_int)]
  
  startRow = which(rownames(raw)==rownames(dataset[1:d_,,drop=FALSE]))
  
  data_ <- c(na.omit(c(dataset[,var_of_int], f_casts)))
  
  if(s_==0)
  {
    inv_d <- diffinv(data_,differences=d_,xi=raw[startRow,var_of_int])
  }else
  {
      
    inv_d <- diffinv(diffinv(data_,differences = d_, xi=raw[startRow,var_of_int]), differences = s_,xi=raw[startRow:(startRow+season-1),var_of_int])
  }
  
  return(inv_d)
  
}

nv_diff_sets(var_of_int,dataframe,c())