Merge two data frames by common columns or row names, or do other versions of database join operations. Show Usagemerge(x, y, ...) ## Default S3 method: merge(x, y, ...) ## S3 method for class 'data.frame' merge(x, y, by = intersect(names(x), names(y)), by.x = by, by.y = by, all = FALSE, all.x = all, all.y = all, sort = TRUE, suffixes = c(".x",".y"), no.dups = TRUE, incomparables = NULL, ...) Argumentsx, y data frames, or objects to be coerced to one. by, by.x, by.y specifications of the columns used for merging. See ‘Details’. all logical; authors <- data.frame( ## I(*) : use character columns of names to get sensible sort order surname = I(c("Tukey", "Venables", "Tierney", "Ripley", "McNeil")), nationality = c("US", "Australia", "US", "UK", "Australia"), deceased = c("yes", rep("no", 4))) authorN <- within(authors, { name <- surname; rm(surname) }) books <- data.frame( name = I(c("Tukey", "Venables", "Tierney", "Ripley", "Ripley", "McNeil", "R Core")), title = c("Exploratory Data Analysis", "Modern Applied Statistics ...", "LISP-STAT", "Spatial Statistics", "Stochastic Simulation", "Interactive Data Analysis", "An Introduction to R"), other.author = c(NA, "Ripley", NA, NA, NA, NA, "Venables & Smith")) (m0 <- merge(authorN, books)) (m1 <- merge(authors, books, by.x = "surname", by.y = "name")) m2 <- merge(books, authors, by.x = "name", by.y = "surname") stopifnot(exprs = { identical(m0, m2[, names(m0)]) as.character(m1[, 1]) == as.character(m2[, 1]) all.equal(m1[, -1], m2[, -1][ names(m1)[-1] ]) identical(dim(merge(m1, m2, by = NULL)), c(nrow(m1)*nrow(m2), ncol(m1)+ncol(m2))) }) ## "R core" is missing from authors and appears only here : merge(authors, books, by.x = "surname", by.y = "name", all = TRUE) ## example of using 'incomparables' x <- data.frame(k1 = c(NA,NA,3,4,5), k2 = c(1,NA,NA,4,5), data = 1:5) y <- data.frame(k1 = c(NA,2,NA,4,5), k2 = c(NA,NA,3,4,5), data = 1:5) merge(x, y, by = c("k1","k2")) # NA's match merge(x, y, by = "k1") # NA's match, so 6 rows merge(x, y, by = "k2", incomparables = NA) # 2 rows0. authors <- data.frame( ## I(*) : use character columns of names to get sensible sort order surname = I(c("Tukey", "Venables", "Tierney", "Ripley", "McNeil")), nationality = c("US", "Australia", "US", "UK", "Australia"), deceased = c("yes", rep("no", 4))) authorN <- within(authors, { name <- surname; rm(surname) }) books <- data.frame( name = I(c("Tukey", "Venables", "Tierney", "Ripley", "Ripley", "McNeil", "R Core")), title = c("Exploratory Data Analysis", "Modern Applied Statistics ...", "LISP-STAT", "Spatial Statistics", "Stochastic Simulation", "Interactive Data Analysis", "An Introduction to R"), other.author = c(NA, "Ripley", NA, NA, NA, NA, "Venables & Smith")) (m0 <- merge(authorN, books)) (m1 <- merge(authors, books, by.x = "surname", by.y = "name")) m2 <- merge(books, authors, by.x = "name", by.y = "surname") stopifnot(exprs = { identical(m0, m2[, names(m0)]) as.character(m1[, 1]) == as.character(m2[, 1]) all.equal(m1[, -1], m2[, -1][ names(m1)[-1] ]) identical(dim(merge(m1, m2, by = NULL)), c(nrow(m1)*nrow(m2), ncol(m1)+ncol(m2))) }) ## "R core" is missing from authors and appears only here : merge(authors, books, by.x = "surname", by.y = "name", all = TRUE) ## example of using 'incomparables' x <- data.frame(k1 = c(NA,NA,3,4,5), k2 = c(1,NA,NA,4,5), data = 1:5) y <- data.frame(k1 = c(NA,2,NA,4,5), k2 = c(NA,NA,3,4,5), data = 1:5) merge(x, y, by = c("k1","k2")) # NA's match merge(x, y, by = "k1") # NA's match, so 6 rows merge(x, y, by = "k2", incomparables = NA) # 2 rows1 logical; if authors <- data.frame( ## I(*) : use character columns of names to get sensible sort order surname = I(c("Tukey", "Venables", "Tierney", "Ripley", "McNeil")), nationality = c("US", "Australia", "US", "UK", "Australia"), deceased = c("yes", rep("no", 4))) authorN <- within(authors, { name <- surname; rm(surname) }) books <- data.frame( name = I(c("Tukey", "Venables", "Tierney", "Ripley", "Ripley", "McNeil", "R Core")), title = c("Exploratory Data Analysis", "Modern Applied Statistics ...", "LISP-STAT", "Spatial Statistics", "Stochastic Simulation", "Interactive Data Analysis", "An Introduction to R"), other.author = c(NA, "Ripley", NA, NA, NA, NA, "Venables & Smith")) (m0 <- merge(authorN, books)) (m1 <- merge(authors, books, by.x = "surname", by.y = "name")) m2 <- merge(books, authors, by.x = "name", by.y = "surname") stopifnot(exprs = { identical(m0, m2[, names(m0)]) as.character(m1[, 1]) == as.character(m2[, 1]) all.equal(m1[, -1], m2[, -1][ names(m1)[-1] ]) identical(dim(merge(m1, m2, by = NULL)), c(nrow(m1)*nrow(m2), ncol(m1)+ncol(m2))) }) ## "R core" is missing from authors and appears only here : merge(authors, books, by.x = "surname", by.y = "name", all = TRUE) ## example of using 'incomparables' x <- data.frame(k1 = c(NA,NA,3,4,5), k2 = c(1,NA,NA,4,5), data = 1:5) y <- data.frame(k1 = c(NA,2,NA,4,5), k2 = c(NA,NA,3,4,5), data = 1:5) merge(x, y, by = c("k1","k2")) # NA's match merge(x, y, by = "k1") # NA's match, so 6 rows merge(x, y, by = "k2", incomparables = NA) # 2 rows3 that has no matching row in authors <- data.frame( ## I(*) : use character columns of names to get sensible sort order surname = I(c("Tukey", "Venables", "Tierney", "Ripley", "McNeil")), nationality = c("US", "Australia", "US", "UK", "Australia"), deceased = c("yes", rep("no", 4))) authorN <- within(authors, { name <- surname; rm(surname) }) books <- data.frame( name = I(c("Tukey", "Venables", "Tierney", "Ripley", "Ripley", "McNeil", "R Core")), title = c("Exploratory Data Analysis", "Modern Applied Statistics ...", "LISP-STAT", "Spatial Statistics", "Stochastic Simulation", "Interactive Data Analysis", "An Introduction to R"), other.author = c(NA, "Ripley", NA, NA, NA, NA, "Venables & Smith")) (m0 <- merge(authorN, books)) (m1 <- merge(authors, books, by.x = "surname", by.y = "name")) m2 <- merge(books, authors, by.x = "name", by.y = "surname") stopifnot(exprs = { identical(m0, m2[, names(m0)]) as.character(m1[, 1]) == as.character(m2[, 1]) all.equal(m1[, -1], m2[, -1][ names(m1)[-1] ]) identical(dim(merge(m1, m2, by = NULL)), c(nrow(m1)*nrow(m2), ncol(m1)+ncol(m2))) }) ## "R core" is missing from authors and appears only here : merge(authors, books, by.x = "surname", by.y = "name", all = TRUE) ## example of using 'incomparables' x <- data.frame(k1 = c(NA,NA,3,4,5), k2 = c(1,NA,NA,4,5), data = 1:5) y <- data.frame(k1 = c(NA,2,NA,4,5), k2 = c(NA,NA,3,4,5), data = 1:5) merge(x, y, by = c("k1","k2")) # NA's match merge(x, y, by = "k1") # NA's match, so 6 rows merge(x, y, by = "k2", incomparables = NA) # 2 rows4. These rows will have authors <- data.frame( ## I(*) : use character columns of names to get sensible sort order surname = I(c("Tukey", "Venables", "Tierney", "Ripley", "McNeil")), nationality = c("US", "Australia", "US", "UK", "Australia"), deceased = c("yes", rep("no", 4))) authorN <- within(authors, { name <- surname; rm(surname) }) books <- data.frame( name = I(c("Tukey", "Venables", "Tierney", "Ripley", "Ripley", "McNeil", "R Core")), title = c("Exploratory Data Analysis", "Modern Applied Statistics ...", "LISP-STAT", "Spatial Statistics", "Stochastic Simulation", "Interactive Data Analysis", "An Introduction to R"), other.author = c(NA, "Ripley", NA, NA, NA, NA, "Venables & Smith")) (m0 <- merge(authorN, books)) (m1 <- merge(authors, books, by.x = "surname", by.y = "name")) m2 <- merge(books, authors, by.x = "name", by.y = "surname") stopifnot(exprs = { identical(m0, m2[, names(m0)]) as.character(m1[, 1]) == as.character(m2[, 1]) all.equal(m1[, -1], m2[, -1][ names(m1)[-1] ]) identical(dim(merge(m1, m2, by = NULL)), c(nrow(m1)*nrow(m2), ncol(m1)+ncol(m2))) }) ## "R core" is missing from authors and appears only here : merge(authors, books, by.x = "surname", by.y = "name", all = TRUE) ## example of using 'incomparables' x <- data.frame(k1 = c(NA,NA,3,4,5), k2 = c(1,NA,NA,4,5), data = 1:5) y <- data.frame(k1 = c(NA,2,NA,4,5), k2 = c(NA,NA,3,4,5), data = 1:5) merge(x, y, by = c("k1","k2")) # NA's match merge(x, y, by = "k1") # NA's match, so 6 rows merge(x, y, by = "k2", incomparables = NA) # 2 rows5s in those columns that are usually filled with values from authors <- data.frame( ## I(*) : use character columns of names to get sensible sort order surname = I(c("Tukey", "Venables", "Tierney", "Ripley", "McNeil")), nationality = c("US", "Australia", "US", "UK", "Australia"), deceased = c("yes", rep("no", 4))) authorN <- within(authors, { name <- surname; rm(surname) }) books <- data.frame( name = I(c("Tukey", "Venables", "Tierney", "Ripley", "Ripley", "McNeil", "R Core")), title = c("Exploratory Data Analysis", "Modern Applied Statistics ...", "LISP-STAT", "Spatial Statistics", "Stochastic Simulation", "Interactive Data Analysis", "An Introduction to R"), other.author = c(NA, "Ripley", NA, NA, NA, NA, "Venables & Smith")) (m0 <- merge(authorN, books)) (m1 <- merge(authors, books, by.x = "surname", by.y = "name")) m2 <- merge(books, authors, by.x = "name", by.y = "surname") stopifnot(exprs = { identical(m0, m2[, names(m0)]) as.character(m1[, 1]) == as.character(m2[, 1]) all.equal(m1[, -1], m2[, -1][ names(m1)[-1] ]) identical(dim(merge(m1, m2, by = NULL)), c(nrow(m1)*nrow(m2), ncol(m1)+ncol(m2))) }) ## "R core" is missing from authors and appears only here : merge(authors, books, by.x = "surname", by.y = "name", all = TRUE) ## example of using 'incomparables' x <- data.frame(k1 = c(NA,NA,3,4,5), k2 = c(1,NA,NA,4,5), data = 1:5) y <- data.frame(k1 = c(NA,2,NA,4,5), k2 = c(NA,NA,3,4,5), data = 1:5) merge(x, y, by = c("k1","k2")) # NA's match merge(x, y, by = "k1") # NA's match, so 6 rows merge(x, y, by = "k2", incomparables = NA) # 2 rows4. The default is authors <- data.frame( ## I(*) : use character columns of names to get sensible sort order surname = I(c("Tukey", "Venables", "Tierney", "Ripley", "McNeil")), nationality = c("US", "Australia", "US", "UK", "Australia"), deceased = c("yes", rep("no", 4))) authorN <- within(authors, { name <- surname; rm(surname) }) books <- data.frame( name = I(c("Tukey", "Venables", "Tierney", "Ripley", "Ripley", "McNeil", "R Core")), title = c("Exploratory Data Analysis", "Modern Applied Statistics ...", "LISP-STAT", "Spatial Statistics", "Stochastic Simulation", "Interactive Data Analysis", "An Introduction to R"), other.author = c(NA, "Ripley", NA, NA, NA, NA, "Venables & Smith")) (m0 <- merge(authorN, books)) (m1 <- merge(authors, books, by.x = "surname", by.y = "name")) m2 <- merge(books, authors, by.x = "name", by.y = "surname") stopifnot(exprs = { identical(m0, m2[, names(m0)]) as.character(m1[, 1]) == as.character(m2[, 1]) all.equal(m1[, -1], m2[, -1][ names(m1)[-1] ]) identical(dim(merge(m1, m2, by = NULL)), c(nrow(m1)*nrow(m2), ncol(m1)+ncol(m2))) }) ## "R core" is missing from authors and appears only here : merge(authors, books, by.x = "surname", by.y = "name", all = TRUE) ## example of using 'incomparables' x <- data.frame(k1 = c(NA,NA,3,4,5), k2 = c(1,NA,NA,4,5), data = 1:5) y <- data.frame(k1 = c(NA,2,NA,4,5), k2 = c(NA,NA,3,4,5), data = 1:5) merge(x, y, by = c("k1","k2")) # NA's match merge(x, y, by = "k1") # NA's match, so 6 rows merge(x, y, by = "k2", incomparables = NA) # 2 rows0, so that only rows with data from both authors <- data.frame( ## I(*) : use character columns of names to get sensible sort order surname = I(c("Tukey", "Venables", "Tierney", "Ripley", "McNeil")), nationality = c("US", "Australia", "US", "UK", "Australia"), deceased = c("yes", rep("no", 4))) authorN <- within(authors, { name <- surname; rm(surname) }) books <- data.frame( name = I(c("Tukey", "Venables", "Tierney", "Ripley", "Ripley", "McNeil", "R Core")), title = c("Exploratory Data Analysis", "Modern Applied Statistics ...", "LISP-STAT", "Spatial Statistics", "Stochastic Simulation", "Interactive Data Analysis", "An Introduction to R"), other.author = c(NA, "Ripley", NA, NA, NA, NA, "Venables & Smith")) (m0 <- merge(authorN, books)) (m1 <- merge(authors, books, by.x = "surname", by.y = "name")) m2 <- merge(books, authors, by.x = "name", by.y = "surname") stopifnot(exprs = { identical(m0, m2[, names(m0)]) as.character(m1[, 1]) == as.character(m2[, 1]) all.equal(m1[, -1], m2[, -1][ names(m1)[-1] ]) identical(dim(merge(m1, m2, by = NULL)), c(nrow(m1)*nrow(m2), ncol(m1)+ncol(m2))) }) ## "R core" is missing from authors and appears only here : merge(authors, books, by.x = "surname", by.y = "name", all = TRUE) ## example of using 'incomparables' x <- data.frame(k1 = c(NA,NA,3,4,5), k2 = c(1,NA,NA,4,5), data = 1:5) y <- data.frame(k1 = c(NA,2,NA,4,5), k2 = c(NA,NA,3,4,5), data = 1:5) merge(x, y, by = c("k1","k2")) # NA's match merge(x, y, by = "k1") # NA's match, so 6 rows merge(x, y, by = "k2", incomparables = NA) # 2 rows3 and authors <- data.frame( ## I(*) : use character columns of names to get sensible sort order surname = I(c("Tukey", "Venables", "Tierney", "Ripley", "McNeil")), nationality = c("US", "Australia", "US", "UK", "Australia"), deceased = c("yes", rep("no", 4))) authorN <- within(authors, { name <- surname; rm(surname) }) books <- data.frame( name = I(c("Tukey", "Venables", "Tierney", "Ripley", "Ripley", "McNeil", "R Core")), title = c("Exploratory Data Analysis", "Modern Applied Statistics ...", "LISP-STAT", "Spatial Statistics", "Stochastic Simulation", "Interactive Data Analysis", "An Introduction to R"), other.author = c(NA, "Ripley", NA, NA, NA, NA, "Venables & Smith")) (m0 <- merge(authorN, books)) (m1 <- merge(authors, books, by.x = "surname", by.y = "name")) m2 <- merge(books, authors, by.x = "name", by.y = "surname") stopifnot(exprs = { identical(m0, m2[, names(m0)]) as.character(m1[, 1]) == as.character(m2[, 1]) all.equal(m1[, -1], m2[, -1][ names(m1)[-1] ]) identical(dim(merge(m1, m2, by = NULL)), c(nrow(m1)*nrow(m2), ncol(m1)+ncol(m2))) }) ## "R core" is missing from authors and appears only here : merge(authors, books, by.x = "surname", by.y = "name", all = TRUE) ## example of using 'incomparables' x <- data.frame(k1 = c(NA,NA,3,4,5), k2 = c(1,NA,NA,4,5), data = 1:5) y <- data.frame(k1 = c(NA,2,NA,4,5), k2 = c(NA,NA,3,4,5), data = 1:5) merge(x, y, by = c("k1","k2")) # NA's match merge(x, y, by = "k1") # NA's match, so 6 rows merge(x, y, by = "k2", incomparables = NA) # 2 rows4 are included in the output. x, y 0logical; analogous to authors <- data.frame( ## I(*) : use character columns of names to get sensible sort order surname = I(c("Tukey", "Venables", "Tierney", "Ripley", "McNeil")), nationality = c("US", "Australia", "US", "UK", "Australia"), deceased = c("yes", rep("no", 4))) authorN <- within(authors, { name <- surname; rm(surname) }) books <- data.frame( name = I(c("Tukey", "Venables", "Tierney", "Ripley", "Ripley", "McNeil", "R Core")), title = c("Exploratory Data Analysis", "Modern Applied Statistics ...", "LISP-STAT", "Spatial Statistics", "Stochastic Simulation", "Interactive Data Analysis", "An Introduction to R"), other.author = c(NA, "Ripley", NA, NA, NA, NA, "Venables & Smith")) (m0 <- merge(authorN, books)) (m1 <- merge(authors, books, by.x = "surname", by.y = "name")) m2 <- merge(books, authors, by.x = "name", by.y = "surname") stopifnot(exprs = { identical(m0, m2[, names(m0)]) as.character(m1[, 1]) == as.character(m2[, 1]) all.equal(m1[, -1], m2[, -1][ names(m1)[-1] ]) identical(dim(merge(m1, m2, by = NULL)), c(nrow(m1)*nrow(m2), ncol(m1)+ncol(m2))) }) ## "R core" is missing from authors and appears only here : merge(authors, books, by.x = "surname", by.y = "name", all = TRUE) ## example of using 'incomparables' x <- data.frame(k1 = c(NA,NA,3,4,5), k2 = c(1,NA,NA,4,5), data = 1:5) y <- data.frame(k1 = c(NA,2,NA,4,5), k2 = c(NA,NA,3,4,5), data = 1:5) merge(x, y, by = c("k1","k2")) # NA's match merge(x, y, by = "k1") # NA's match, so 6 rows merge(x, y, by = "k2", incomparables = NA) # 2 rows1. x, y 2logical. Should the result be sorted on the x, y 4a character vector of length 2 specifying the suffixes to be used for making unique the names of columns in the result which are not used for merging (appearing in x, y 6logical indicating that x, y 8values which cannot be matched. See by, by.x, by.y 0arguments to be passed to or from methods. Details
By default the data frames are merged on the columns with names they both have, but separate specifications of the columns can be given by Columns to merge on can be specified by name, number or by a logical vector: the name If authors <- data.frame( ## I(*) : use character columns of names to get sensible sort order surname = I(c("Tukey", "Venables", "Tierney", "Ripley", "McNeil")), nationality = c("US", "Australia", "US", "UK", "Australia"), deceased = c("yes", rep("no", 4))) authorN <- within(authors, { name <- surname; rm(surname) }) books <- data.frame( name = I(c("Tukey", "Venables", "Tierney", "Ripley", "Ripley", "McNeil", "R Core")), title = c("Exploratory Data Analysis", "Modern Applied Statistics ...", "LISP-STAT", "Spatial Statistics", "Stochastic Simulation", "Interactive Data Analysis", "An Introduction to R"), other.author = c(NA, "Ripley", NA, NA, NA, NA, "Venables & Smith")) (m0 <- merge(authorN, books)) (m1 <- merge(authors, books, by.x = "surname", by.y = "name")) m2 <- merge(books, authors, by.x = "name", by.y = "surname") stopifnot(exprs = { identical(m0, m2[, names(m0)]) as.character(m1[, 1]) == as.character(m2[, 1]) all.equal(m1[, -1], m2[, -1][ names(m1)[-1] ]) identical(dim(merge(m1, m2, by = NULL)), c(nrow(m1)*nrow(m2), ncol(m1)+ncol(m2))) }) ## "R core" is missing from authors and appears only here : merge(authors, books, by.x = "surname", by.y = "name", all = TRUE) ## example of using 'incomparables' x <- data.frame(k1 = c(NA,NA,3,4,5), k2 = c(1,NA,NA,4,5), data = 1:5) y <- data.frame(k1 = c(NA,2,NA,4,5), k2 = c(NA,NA,3,4,5), data = 1:5) merge(x, y, by = c("k1","k2")) # NA's match merge(x, y, by = "k1") # NA's match, so 6 rows merge(x, y, by = "k2", incomparables = NA) # 2 rows3 and authors <- data.frame( ## I(*) : use character columns of names to get sensible sort order surname = I(c("Tukey", "Venables", "Tierney", "Ripley", "McNeil")), nationality = c("US", "Australia", "US", "UK", "Australia"), deceased = c("yes", rep("no", 4))) authorN <- within(authors, { name <- surname; rm(surname) }) books <- data.frame( name = I(c("Tukey", "Venables", "Tierney", "Ripley", "Ripley", "McNeil", "R Core")), title = c("Exploratory Data Analysis", "Modern Applied Statistics ...", "LISP-STAT", "Spatial Statistics", "Stochastic Simulation", "Interactive Data Analysis", "An Introduction to R"), other.author = c(NA, "Ripley", NA, NA, NA, NA, "Venables & Smith")) (m0 <- merge(authorN, books)) (m1 <- merge(authors, books, by.x = "surname", by.y = "name")) m2 <- merge(books, authors, by.x = "name", by.y = "surname") stopifnot(exprs = { identical(m0, m2[, names(m0)]) as.character(m1[, 1]) == as.character(m2[, 1]) all.equal(m1[, -1], m2[, -1][ names(m1)[-1] ]) identical(dim(merge(m1, m2, by = NULL)), c(nrow(m1)*nrow(m2), ncol(m1)+ncol(m2))) }) ## "R core" is missing from authors and appears only here : merge(authors, books, by.x = "surname", by.y = "name", all = TRUE) ## example of using 'incomparables' x <- data.frame(k1 = c(NA,NA,3,4,5), k2 = c(1,NA,NA,4,5), data = 1:5) y <- data.frame(k1 = c(NA,2,NA,4,5), k2 = c(NA,NA,3,4,5), data = 1:5) merge(x, y, by = c("k1","k2")) # NA's match merge(x, y, by = "k1") # NA's match, so 6 rows merge(x, y, by = "k2", incomparables = NA) # 2 rows4, i.e., all 5.If authors <- data.frame( ## I(*) : use character columns of names to get sensible sort order surname = I(c("Tukey", "Venables", "Tierney", "Ripley", "McNeil")), nationality = c("US", "Australia", "US", "UK", "Australia"), deceased = c("yes", rep("no", 4))) authorN <- within(authors, { name <- surname; rm(surname) }) books <- data.frame( name = I(c("Tukey", "Venables", "Tierney", "Ripley", "Ripley", "McNeil", "R Core")), title = c("Exploratory Data Analysis", "Modern Applied Statistics ...", "LISP-STAT", "Spatial Statistics", "Stochastic Simulation", "Interactive Data Analysis", "An Introduction to R"), other.author = c(NA, "Ripley", NA, NA, NA, NA, "Venables & Smith")) (m0 <- merge(authorN, books)) (m1 <- merge(authors, books, by.x = "surname", by.y = "name")) m2 <- merge(books, authors, by.x = "name", by.y = "surname") stopifnot(exprs = { identical(m0, m2[, names(m0)]) as.character(m1[, 1]) == as.character(m2[, 1]) all.equal(m1[, -1], m2[, -1][ names(m1)[-1] ]) identical(dim(merge(m1, m2, by = NULL)), c(nrow(m1)*nrow(m2), ncol(m1)+ncol(m2))) }) ## "R core" is missing from authors and appears only here : merge(authors, books, by.x = "surname", by.y = "name", all = TRUE) ## example of using 'incomparables' x <- data.frame(k1 = c(NA,NA,3,4,5), k2 = c(1,NA,NA,4,5), data = 1:5) y <- data.frame(k1 = c(NA,2,NA,4,5), k2 = c(NA,NA,3,4,5), data = 1:5) merge(x, y, by = c("k1","k2")) # NA's match merge(x, y, by = "k1") # NA's match, so 6 rows merge(x, y, by = "k2", incomparables = NA) # 2 rows1 is true, all the non matching cases of authors <- data.frame( ## I(*) : use character columns of names to get sensible sort order surname = I(c("Tukey", "Venables", "Tierney", "Ripley", "McNeil")), nationality = c("US", "Australia", "US", "UK", "Australia"), deceased = c("yes", rep("no", 4))) authorN <- within(authors, { name <- surname; rm(surname) }) books <- data.frame( name = I(c("Tukey", "Venables", "Tierney", "Ripley", "Ripley", "McNeil", "R Core")), title = c("Exploratory Data Analysis", "Modern Applied Statistics ...", "LISP-STAT", "Spatial Statistics", "Stochastic Simulation", "Interactive Data Analysis", "An Introduction to R"), other.author = c(NA, "Ripley", NA, NA, NA, NA, "Venables & Smith")) (m0 <- merge(authorN, books)) (m1 <- merge(authors, books, by.x = "surname", by.y = "name")) m2 <- merge(books, authors, by.x = "name", by.y = "surname") stopifnot(exprs = { identical(m0, m2[, names(m0)]) as.character(m1[, 1]) == as.character(m2[, 1]) all.equal(m1[, -1], m2[, -1][ names(m1)[-1] ]) identical(dim(merge(m1, m2, by = NULL)), c(nrow(m1)*nrow(m2), ncol(m1)+ncol(m2))) }) ## "R core" is missing from authors and appears only here : merge(authors, books, by.x = "surname", by.y = "name", all = TRUE) ## example of using 'incomparables' x <- data.frame(k1 = c(NA,NA,3,4,5), k2 = c(1,NA,NA,4,5), data = 1:5) y <- data.frame(k1 = c(NA,2,NA,4,5), k2 = c(NA,NA,3,4,5), data = 1:5) merge(x, y, by = c("k1","k2")) # NA's match merge(x, y, by = "k1") # NA's match, so 6 rows merge(x, y, by = "k2", incomparables = NA) # 2 rows3 are appended to the result as well, with authors <- data.frame( ## I(*) : use character columns of names to get sensible sort order surname = I(c("Tukey", "Venables", "Tierney", "Ripley", "McNeil")), nationality = c("US", "Australia", "US", "UK", "Australia"), deceased = c("yes", rep("no", 4))) authorN <- within(authors, { name <- surname; rm(surname) }) books <- data.frame( name = I(c("Tukey", "Venables", "Tierney", "Ripley", "Ripley", "McNeil", "R Core")), title = c("Exploratory Data Analysis", "Modern Applied Statistics ...", "LISP-STAT", "Spatial Statistics", "Stochastic Simulation", "Interactive Data Analysis", "An Introduction to R"), other.author = c(NA, "Ripley", NA, NA, NA, NA, "Venables & Smith")) (m0 <- merge(authorN, books)) (m1 <- merge(authors, books, by.x = "surname", by.y = "name")) m2 <- merge(books, authors, by.x = "name", by.y = "surname") stopifnot(exprs = { identical(m0, m2[, names(m0)]) as.character(m1[, 1]) == as.character(m2[, 1]) all.equal(m1[, -1], m2[, -1][ names(m1)[-1] ]) identical(dim(merge(m1, m2, by = NULL)), c(nrow(m1)*nrow(m2), ncol(m1)+ncol(m2))) }) ## "R core" is missing from authors and appears only here : merge(authors, books, by.x = "surname", by.y = "name", all = TRUE) ## example of using 'incomparables' x <- data.frame(k1 = c(NA,NA,3,4,5), k2 = c(1,NA,NA,4,5), data = 1:5) y <- data.frame(k1 = c(NA,2,NA,4,5), k2 = c(NA,NA,3,4,5), data = 1:5) merge(x, y, by = c("k1","k2")) # NA's match merge(x, y, by = "k1") # NA's match, so 6 rows merge(x, y, by = "k2", incomparables = NA) # 2 rows5 filled in the corresponding columns of authors <- data.frame( ## I(*) : use character columns of names to get sensible sort order surname = I(c("Tukey", "Venables", "Tierney", "Ripley", "McNeil")), nationality = c("US", "Australia", "US", "UK", "Australia"), deceased = c("yes", rep("no", 4))) authorN <- within(authors, { name <- surname; rm(surname) }) books <- data.frame( name = I(c("Tukey", "Venables", "Tierney", "Ripley", "Ripley", "McNeil", "R Core")), title = c("Exploratory Data Analysis", "Modern Applied Statistics ...", "LISP-STAT", "Spatial Statistics", "Stochastic Simulation", "Interactive Data Analysis", "An Introduction to R"), other.author = c(NA, "Ripley", NA, NA, NA, NA, "Venables & Smith")) (m0 <- merge(authorN, books)) (m1 <- merge(authors, books, by.x = "surname", by.y = "name")) m2 <- merge(books, authors, by.x = "name", by.y = "surname") stopifnot(exprs = { identical(m0, m2[, names(m0)]) as.character(m1[, 1]) == as.character(m2[, 1]) all.equal(m1[, -1], m2[, -1][ names(m1)[-1] ]) identical(dim(merge(m1, m2, by = NULL)), c(nrow(m1)*nrow(m2), ncol(m1)+ncol(m2))) }) ## "R core" is missing from authors and appears only here : merge(authors, books, by.x = "surname", by.y = "name", all = TRUE) ## example of using 'incomparables' x <- data.frame(k1 = c(NA,NA,3,4,5), k2 = c(1,NA,NA,4,5), data = 1:5) y <- data.frame(k1 = c(NA,2,NA,4,5), k2 = c(NA,NA,3,4,5), data = 1:5) merge(x, y, by = c("k1","k2")) # NA's match merge(x, y, by = "k1") # NA's match, so 6 rows merge(x, y, by = "k2", incomparables = NA) # 2 rows4; analogously for x, y 0.If the columns in the data frames not used in merging have any common names, these have If a authors <- data.frame( ## I(*) : use character columns of names to get sensible sort order surname = I(c("Tukey", "Venables", "Tierney", "Ripley", "McNeil")), nationality = c("US", "Australia", "US", "UK", "Australia"), deceased = c("yes", rep("no", 4))) authorN <- within(authors, { name <- surname; rm(surname) }) books <- data.frame( name = I(c("Tukey", "Venables", "Tierney", "Ripley", "Ripley", "McNeil", "R Core")), title = c("Exploratory Data Analysis", "Modern Applied Statistics ...", "LISP-STAT", "Spatial Statistics", "Stochastic Simulation", "Interactive Data Analysis", "An Introduction to R"), other.author = c(NA, "Ripley", NA, NA, NA, NA, "Venables & Smith")) (m0 <- merge(authorN, books)) (m1 <- merge(authors, books, by.x = "surname", by.y = "name")) m2 <- merge(books, authors, by.x = "name", by.y = "surname") stopifnot(exprs = { identical(m0, m2[, names(m0)]) as.character(m1[, 1]) == as.character(m2[, 1]) all.equal(m1[, -1], m2[, -1][ names(m1)[-1] ]) identical(dim(merge(m1, m2, by = NULL)), c(nrow(m1)*nrow(m2), ncol(m1)+ncol(m2))) }) ## "R core" is missing from authors and appears only here : merge(authors, books, by.x = "surname", by.y = "name", all = TRUE) ## example of using 'incomparables' x <- data.frame(k1 = c(NA,NA,3,4,5), k2 = c(1,NA,NA,4,5), data = 1:5) y <- data.frame(k1 = c(NA,2,NA,4,5), k2 = c(NA,NA,3,4,5), data = 1:5) merge(x, y, by = c("k1","k2")) # NA's match merge(x, y, by = "k1") # NA's match, so 6 rows merge(x, y, by = "k2", incomparables = NA) # 2 rows4, and if x, y 6 is true (as by default), the y version gets suffixed as well, avoiding duplicate column names in the result.The complexity of the algorithm used is proportional to the length of the answer. In SQL database terminology, the default value of ValueA data frame. The rows are by default lexicographically sorted on the common columns, but for authors <- data.frame( ## I(*) : use character columns of names to get sensible sort order surname = I(c("Tukey", "Venables", "Tierney", "Ripley", "McNeil")), nationality = c("US", "Australia", "US", "UK", "Australia"), deceased = c("yes", rep("no", 4))) authorN <- within(authors, { name <- surname; rm(surname) }) books <- data.frame( name = I(c("Tukey", "Venables", "Tierney", "Ripley", "Ripley", "McNeil", "R Core")), title = c("Exploratory Data Analysis", "Modern Applied Statistics ...", "LISP-STAT", "Spatial Statistics", "Stochastic Simulation", "Interactive Data Analysis", "An Introduction to R"), other.author = c(NA, "Ripley", NA, NA, NA, NA, "Venables & Smith")) (m0 <- merge(authorN, books)) (m1 <- merge(authors, books, by.x = "surname", by.y = "name")) m2 <- merge(books, authors, by.x = "name", by.y = "surname") stopifnot(exprs = { identical(m0, m2[, names(m0)]) as.character(m1[, 1]) == as.character(m2[, 1]) all.equal(m1[, -1], m2[, -1][ names(m1)[-1] ]) identical(dim(merge(m1, m2, by = NULL)), c(nrow(m1)*nrow(m2), ncol(m1)+ncol(m2))) }) ## "R core" is missing from authors and appears only here : merge(authors, books, by.x = "surname", by.y = "name", all = TRUE) ## example of using 'incomparables' x <- data.frame(k1 = c(NA,NA,3,4,5), k2 = c(1,NA,NA,4,5), data = 1:5) y <- data.frame(k1 = c(NA,2,NA,4,5), k2 = c(NA,NA,3,4,5), data = 1:5) merge(x, y, by = c("k1","k2")) # NA's match merge(x, y, by = "k1") # NA's match, so 6 rows merge(x, y, by = "k2", incomparables = NA) # 2 rows3 and then those in authors <- data.frame( ## I(*) : use character columns of names to get sensible sort order surname = I(c("Tukey", "Venables", "Tierney", "Ripley", "McNeil")), nationality = c("US", "Australia", "US", "UK", "Australia"), deceased = c("yes", rep("no", 4))) authorN <- within(authors, { name <- surname; rm(surname) }) books <- data.frame( name = I(c("Tukey", "Venables", "Tierney", "Ripley", "Ripley", "McNeil", "R Core")), title = c("Exploratory Data Analysis", "Modern Applied Statistics ...", "LISP-STAT", "Spatial Statistics", "Stochastic Simulation", "Interactive Data Analysis", "An Introduction to R"), other.author = c(NA, "Ripley", NA, NA, NA, NA, "Venables & Smith")) (m0 <- merge(authorN, books)) (m1 <- merge(authors, books, by.x = "surname", by.y = "name")) m2 <- merge(books, authors, by.x = "name", by.y = "surname") stopifnot(exprs = { identical(m0, m2[, names(m0)]) as.character(m1[, 1]) == as.character(m2[, 1]) all.equal(m1[, -1], m2[, -1][ names(m1)[-1] ]) identical(dim(merge(m1, m2, by = NULL)), c(nrow(m1)*nrow(m2), ncol(m1)+ncol(m2))) }) ## "R core" is missing from authors and appears only here : merge(authors, books, by.x = "surname", by.y = "name", all = TRUE) ## example of using 'incomparables' x <- data.frame(k1 = c(NA,NA,3,4,5), k2 = c(1,NA,NA,4,5), data = 1:5) y <- data.frame(k1 = c(NA,2,NA,4,5), k2 = c(NA,NA,3,4,5), data = 1:5) merge(x, y, by = c("k1","k2")) # NA's match merge(x, y, by = "k1") # NA's match, so 6 rows merge(x, y, by = "k2", incomparables = NA) # 2 rows4. If the matching involved row names, an extra character column called all.x = L 6 is added at the left, and in all cases the result has ‘automatic’ row names.NoteThis is intended to work with data frames with vector-like columns: some aspects work with data frames containing matrices, but not all. Currently long vectors are not accepted for inputs, which are thus restricted to less than 2^31 rows. That restriction also applies to the result for 32-bit platforms. How to merge two dataframes with different length in R?Steps –. Create first dataframe.. Create second dataframe.. Use any function from the given below and combine them.. Display dataset so created.. How do I combine two vectors with different lengths in R?The easiest way to use cbind in R with vectors of different lengths is to set the vectors to equal lengths using the length() function.
How to combine two data frames in R?In R we use merge() function to merge two dataframes in R. This function is present inside join() function of dplyr package. The most important condition for joining two dataframes is that the column type should be the same on which the merging happens. merge() function works similarly like join in DBMS.
How do I merge two Dataframes with different columns in R?How to Join Data Frames for different column names in R. library(dplyr) left_join(df1, df2, by=c('x1'='x2', 'y1'='y2')) ... . df3 <- left_join(df1, df2, by=c('team'='team_name', 'pos'='position')) df3 <- left_join(df1, df2, by=c('team'='team_name', 'pos'='position')). library(dplyr). |