R: Convert Excel Column Name into Column Number

1 - Excel Name to Number.R

#==============================================================================
# purpose: get the column number from the column name in Excel 
# author: tirthankar chakravarty
# created: 22nd february 2016
# revised: 22nd february 2016
# comments: 
# - based on this SO answer: http://stackoverflow.com/a/1004624/1414455
#==============================================================================

excel_name_to_number = function(name) {
  Reduce(function(cumulative, next_element) {
    cumulative*26 + utf8ToInt(next_element) - utf8ToInt("A") + 1
  }, x = strsplit(name, "")[[1]], init = 0)
}

excel_name_to_number("AAR")  # 720
excel_name_to_number("AR")  # 44