vignettes/merge.md

In fdetsch/Orcs: Omnidirectional R Code Snippets

title: "Merge multiple data frames with multiMerge" author: "Florian Detsch" date: "2018-05-31" output: rmarkdown::html_vignette vignette: > %\VignetteIndexEntry{Merge multiple data frames with multiMerge} %\VignetteEngine{knitr::knitr} %\VignetteEncoding{UTF-8}

Merging multiple data frames in R is anything but straightforward and usually involves confusing loop structures. multiMerge elegantly avoids such bewildering code chunks by invoking Reduce upon a list of data frames. The function also features a set of auxiliary parameters that are passed on to merge. Note that the code is mainly taken from a related blog post in StackOverflow.

## sample data
set.seed(10)
ls_df <- list(data.frame(a = 1:10, b = 1:10),
              data.frame(a = 5:14, c = 11:20),
              data.frame(a = sample(20, 10), d = runif(10)))

## merge data frames in one go
merge(ls_df, by = "a", all = TRUE)

##     a  b  c          d
## 1   1  1 NA         NA
## 2   2  2 NA 0.35804998
## 3   3  3 NA         NA
## 4   4  4 NA 0.42880942
## 5   5  5 11 0.83613414
## 6   6  6 12 0.56773775
## 7   7  7 13         NA
## 8   8  8 14 0.11350898
## 9   9  9 15         NA
## 10 10 10 16         NA
## 11 11 NA 17 0.65165567
## 12 12 NA 18 0.59592531
## 13 13 NA 19         NA
## 14 14 NA 20 0.26417767
## 15 15 NA NA 0.05190332
## 16 18 NA NA 0.39879073

fdetsch/Orcs documentation built on Jan. 9, 2023, 6:14 a.m.