CODEWITHSUNDEEP
rdataframe
Martin Walczyński
Martin Walczyński

Reputation: 93

Comparing two dataframes with different length in R

I am trying to assign values from market data set (length of 997 objects) to another (t_final) data set (length of 680 obj) based on certain criteria.

market_dt consists of columns: ref.date and ret.closing.prices t_final consists of columns: date and compound

both datasets have dates in same format YYYY-MM-DD

I wanted to make a loop working as such (see below) that my ret.closing.prices value will be copied to a new column in t_final dataset IF the dates match.

   for i in 1:997 {
  if (market_dt[]$ref.date == t_final[]$date){
  t_final[]$return <- market_dt[]$ret.closing.prices
}

However I get the errors:

Warning messages:
1: In `==.default`(market_dt[]$ref.date, t_final[]$date) :
  longer object length is not a multiple of shorter object length
2: In if (market_dt[]$ref.date == t_final[]$date) { :
  the condition has length > 1 and only the first element will be used

How can I properly make this work?

Thank you!

Upvotes: 0

Views: 531

Answers (1)

Hong
Hong

Reputation: 594

You can use 'join' function:

library(dplyr)
left_join(t_final, market_dt, by = c("date" = "ref.date")) %>% 
  rename(return = ret.closing.prices)

Upvotes: 1

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