Storing looping rows in R

Question

laststop <- NULL
stopinfo <- NULL
for (i in journeys$JourneyID){
  laststop <- get_last_stop(i)
  stopinfo <- c(stop_info(i,laststop))
  final_stops <- data.frame(stopinfo)
  }

Basically, through stop_info function with two variables laststop and I, I can get a output 1 row with 8colums. I can get only one row with this data.freme code above. What I want to get is a complete dataframe named final_stops. when I type rint(final_stops), I can see the whole 300 outcomes I need. But I don't know how to make it into the complete dataframe

Answer 1

Difficult to tell if you do not show a minimum reproducible example. But, assuming you get every iteration a data.frame of one row, same columns and you would like to have all of them together, you could use rbind():

laststop <- NULL
stopinfo <- NULL
for (i in journeys$JourneyID){
  laststop <- get_last_stop(i)
  stopinfo <- c(stop_info(i,laststop))
  if (i==1){  # If it is the first iteration: creates the variable
  final_stops <- data.frame(stopinfo)
  }   # if it is second or later iteration, bind by row
  else {
    final_stops <- rbind(final_stops , data.frame(stopinfo)) # combine rows
  }
}

However, this is probably not the best solution and likely you could apply your functions in a tidyverse/data.frame operations much cleaner way. But with custom functions and not a data example, impossible to say.