transfer: Transfer information between two dataframes.
In LudvigOlsen/transfrr: Transfers Information Between Dataframes

Description Usage Arguments Details Value Author(s) Examples

View source: R/transfer.R

Add summary information from one dataframe to the dataframe that has been summarized, given only starting posititions of summarized groups.

E.g. used when one dataframe consists of timestamped samples and another contains summary information about blocks of time. Imagine a sampled heart rate with columns 'time' and 'signal' in one dataframe and information about events that happened in blocks of the sampling, with start times of the blocks, in the other dataframe. See Examples.

1 2	transfer(to, from, by, insert_missing = TRUE, order_to = TRUE, order_from = TRUE)

`to`	Dataframe to transfer information to.
`from`	Dataframe to get information from.
`by`	Names of columns to match starting positions by. Given as vector `c("to", "from")` or just `"shared"` if it's named the same in both dataframes. (Character) E.g. `by = c("time", "start_time")`
`insert_missing`	If some starting positions are not found in the `to` dataframe: Insert them in new rows `>>` Order the dataframe by the `by` column `>>` Transfer the summary information `>>` Remove the inserted rows. (Logical)
`order_to`	Order the `to` dataframe by its `by` column first. (Logical)
`order_from`	Order the `from` dataframe by its `by` column first. (Logical)

Starting positions are the values in the by column of the from dataframe.

The to dataframe with the added columns from the from dataframe.

Ludvig Renbo Olsen, r-pkgs@ludvigolsen.dk

# Attach packages
library(transfrr)
library(dplyr)

# Get data (Note: loaded with transfrr)
sunspots <- sunspots_
presidents <- USA.presidents

# Transfer the presidents' information
# to the time of their presidency
transferred <- sunspots %>%
  transfer(presidents, by = c("start_date", "took_office"))

# Note that the first rows will contain NAs, as they lie
# before the first US president. Check the tail for proof
# that it works.
tail(transferred)