How can the inputs of a function be saved into a data frame?-CodePudding

I need a little help modifying a script to make it simpler and less "hard-coded". The below code creates a data frame of 10 columns with headers "Find" followed by two rows. The first row is the column name to be replaced, and the second row is the name to replace with.

names_subs_list<-data.frame("Find1"=c("Fecha","smpl_date"),
                                 "Find2"=c("1reCODIGODEARBOL","first_tree_code"), 
                                 "Find3"=c("2doCODIGODEARBOL","second_tree_code"), 
                                 "Find4"=c("ALTURADELACAMARAENELFUSTE","chamber_height_and_rep"), 
                                 "Find5"=c("Nombredearchivo","LICOR_CO2_data_file_name"),
                                 "Find6"=c("Especiedearbol","tree_spp"), 
                                 "Find7"=c("Horadecerrarlaoruga","raw_start_time"), 
                                 "Find8"=c("Horadeabrirlaoruga","raw_end_time"), 
                                 "Find9"=c("Nombredecamarausada","chamber_number"),
                                 "Find10"=c("PENDIENTE/FRECUENCIA(ppb)","spot_flux"), stringsAsFactors = F)

I'd like to separate this section of code to a new function or package that could be opened and modified as needed without having to work in the larger QC script. Ideally non- R savvy individuals could enter their own combinations of replacement and replacer values that will be added to this dataframe for future use. My idea for this was a function that would save the inputs into this list.

add_to_list <- function(original_header, replacement_header){

substitutes <-  data.frame("Find1"=c(original_header, replacement_header)
                                ,stringsasFactors = F)
}

Something like the above with a for loop that adds each new addition onto the end of the dataframe. This way new users could enter add_to_list(their_original_headings, their_replacements). If anyone knows how this can be done, or has a better suggestion please let me know.

CodePudding user response：

Iteratively adding columns is fine, not anywhere near as bad as iteratively adding rows (see "Growing Objects" in The R Inferno).

I suggest making your function accept the input data (not trying to find and overwrite it in the calling environment/frame) and returning it.

add_to_list <- function(data = NULL, orig, repl) {
  if (is.null(data)) {
    data <- data.frame(Find1 = c(orig, repl))
  } else {
    maxnum <- suppressWarnings(max(as.integer(gsub("\\D", "", colnames(data)))))
    if (is.na(maxnum) || !length(maxnum)) maxnum <- 0L
    newdata <- data.frame(a = c(orig, repl))
    names(newdata)[1] <- paste0("Find", maxnum 1L)
    data <- cbind(data, newdata)
  }
  data
}

## initial use?
add_to_list(orig="PENDIENTE/FRECUENCIA(ppb)", repl="spot_flux")
#                       Find1
# 1 PENDIENTE/FRECUENCIA(ppb)
# 2                 spot_flux

Now starting from a pre-built frame, note that I commented out "Find10":

names_subs_list <- data.frame(
  "Find1"=c("Fecha","smpl_date"),
  "Find2"=c("1reCODIGODEARBOL","first_tree_code"), 
  "Find3"=c("2doCODIGODEARBOL","second_tree_code"), 
  "Find4"=c("ALTURADELACAMARAENELFUSTE","chamber_height_and_rep"), 
  "Find5"=c("Nombredearchivo","LICOR_CO2_data_file_name"),
  "Find6"=c("Especiedearbol","tree_spp"), 
  "Find7"=c("Horadecerrarlaoruga","raw_start_time"), 
  "Find8"=c("Horadeabrirlaoruga","raw_end_time"), 
  "Find9"=c("Nombredecamarausada","chamber_number"),
  # "Find10"=c("PENDIENTE/FRECUENCIA(ppb)","spot_flux")
  stringsAsFactors = F)

names_subs_list <- add_to_list(names_subs_list, "PENDIENTE/FRECUENCIA(ppb)", "spot_flux")
names_subs_list
#       Find1            Find2            Find3                     Find4                    Find5          Find6               Find7              Find8               Find9                    Find10
# 1     Fecha 1reCODIGODEARBOL 2doCODIGODEARBOL ALTURADELACAMARAENELFUSTE          Nombredearchivo Especiedearbol Horadecerrarlaoruga Horadeabrirlaoruga Nombredecamarausada PENDIENTE/FRECUENCIA(ppb)
# 2 smpl_date  first_tree_code second_tree_code    chamber_height_and_rep LICOR_CO2_data_file_name       tree_spp      raw_start_time       raw_end_time      chamber_number                 spot_flux

names_subs_list <- add_to_list(names_subs_list, "something else", "again")
names_subs_list
#       Find1            Find2            Find3                     Find4                    Find5          Find6               Find7              Find8               Find9                    Find10         Find11
# 1     Fecha 1reCODIGODEARBOL 2doCODIGODEARBOL ALTURADELACAMARAENELFUSTE          Nombredearchivo Especiedearbol Horadecerrarlaoruga Horadeabrirlaoruga Nombredecamarausada PENDIENTE/FRECUENCIA(ppb) something else
# 2 smpl_date  first_tree_code second_tree_code    chamber_height_and_rep LICOR_CO2_data_file_name       tree_spp      raw_start_time       raw_end_time      chamber_number                 spot_flux          again