rbind-set: Add Rows to Data Objects
In str2str: Convert R Objects from One Structure to Another
rbind<- R Documentation
Add Rows to Data Objects
Description
`rbind<-` adds rows to data objects as a side effect. The purpose of
the function is to replace the need to use dat2 <- rbind(dat1, add1);
dat3 <- rbind(dat2, add2); dat4 <- rbind(dat3, add3), etc. For data.frames,
it functions similarly to `[<-.data.frame`, but allows you to specify the
location of the rows similar to append (vs. c) and overwrite
rows with the same rownames. For matrices, it offers more novel functionality
since `[<-.matrix` does not exist.
Usage
rbind(data, after = nrow(data), row.nm = NULL, overwrite = TRUE) <- value
Arguments
data
data.frame or matrix of data.
after
either an integer vector with length 1 or a character vector of
length 1 specifying where to add value. If an integer vector, it is the
position of a row. If a character vector it is the row with that name.
Similar to append, use 0L if you want the added rows to be first.
row.nm
character vector of length equal to NROW(value) that
specifies the rownames of value once added to data as columns.
This is an optional argument that defaults to NULL where the pre-existing rownames
of value are used.
overwrite
logical vector of length 1 specifying whether rows from
value or row.nm should overwrite rows in data with the
same rownames. Note, if overwrite = FALSE, R will prevent repeat rownames
by adding "1" to the end of the repeat rownames similar to rbind.
value
data.frame, matrix, or atomic vector to be added as rows to
data. If a data.frame or matrix, it must have the same ncol as data.
If an atomic vector, it must have length equal to ncol of data.
Details
Some traditional R folks may find this function uncomfortable. R is famous for limiting
side effects, except for a few notable exceptions (e.g., `[<-` and `names<-`).
Part of the reason is that side effects can be computationally inefficient in R.
The entire object often has to be re-constructed and re-saved to memory. For
example, a more computationally efficient alternative to rbind(dat) <- add1;
rbind(dat) <- add2; rbind(dat) <- add3 is dat1 <- do.call(what = rbind,
args = list(dat, add1, add2, add3)). However, `rbind<-` was not created
for R programming use when computational efficiency is valued; it is created
for R interactive use when user convenience is valued.
Similar to `rbind`, `rbind<-` works with both data.frames and matrices.
This is because `rbind` is a generic function with a default method that
works with matrices and a data.frame method that works with data.frames. Similar
to `rbind`, if rownames of value are not given and row.nm
is left NULL, then the rownames of the return object are automatically created
and can be dissatisfying.
Value
Like other similar functions (e.g., `names<-` and `[<-`),
`rbind<-` does not appear to have a return object. However, it technically
does as a side effect. The argument data will have been changed such that
value has been added as rows. If a traditional return object is desired,
and no side effects, then it can be called like a traditional function:
dat2 <- 'rbind<-'(dat1, value = add1).
Examples
attitude2 <- attitude
rbind(attitude2) <- colMeans(attitude2) # defaults to rownames = as.character(nrow(`data`) + 1)
attitude2 <- attitude2[!(`%in%`(x = row.names(attitude2), table = "31")), ] # logical subset
rbind(attitude2, row.nm = "mean") <- colMeans(attitude2)
attitude2 <- attitude2[-1*(match(x = "mean", table = row.names(attitude2))), ] # position subset
rbind(attitude2, after = "10", row.nm = c("mean","sum")) <-
rbind(colMeans(attitude2), colSums(attitude2)) # `value` as a matrix
attitude2 <- attitude2[grep(pattern = "mean|sum", x = row.names(attitude2),
invert = TRUE), ] # rownames subset
attitude2 <- `rbind<-`(data = attitude2, value = colMeans(attitude2)) # traditional call
attitude2 <- as.matrix(attitude, rownames.force = TRUE) # as.matrix.data.frame
rbind(attitude2, after = "10", row.nm = "mean") <- colMeans(attitude2) # `data` as a matrix
# using overwrite
mtcars2 <- mtcars
rownames(mtcars2)
add <- mtcars[c("Mazda RX4","Mazda RX4 Wag","Datsun 710"), ]*11
rbind(mtcars2, overwrite = TRUE) <- add
mtcars2 <- mtcars
rbind(mtcars2, overwrite = FALSE) <- add
str2str documentation built on Nov. 21, 2023, 1:08 a.m.
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| rbind<- | R Documentation |
Add Rows to Data Objects
Description
`rbind<-` adds rows to data objects as a side effect. The purpose of
the function is to replace the need to use dat2 <- rbind(dat1, add1);
dat3 <- rbind(dat2, add2); dat4 <- rbind(dat3, add3), etc. For data.frames,
it functions similarly to `[<-.data.frame`, but allows you to specify the
location of the rows similar to append (vs. c) and overwrite
rows with the same rownames. For matrices, it offers more novel functionality
since `[<-.matrix` does not exist.
Usage
rbind(data, after = nrow(data), row.nm = NULL, overwrite = TRUE) <- value
Arguments
data |
data.frame or matrix of data. |
after |
either an integer vector with length 1 or a character vector of
length 1 specifying where to add |
row.nm |
character vector of length equal to |
overwrite |
logical vector of length 1 specifying whether rows from
|
value |
data.frame, matrix, or atomic vector to be added as rows to
|
Details
Some traditional R folks may find this function uncomfortable. R is famous for limiting
side effects, except for a few notable exceptions (e.g., `[<-` and `names<-`).
Part of the reason is that side effects can be computationally inefficient in R.
The entire object often has to be re-constructed and re-saved to memory. For
example, a more computationally efficient alternative to rbind(dat) <- add1;
rbind(dat) <- add2; rbind(dat) <- add3 is dat1 <- do.call(what = rbind,
args = list(dat, add1, add2, add3)). However, `rbind<-` was not created
for R programming use when computational efficiency is valued; it is created
for R interactive use when user convenience is valued.
Similar to `rbind`, `rbind<-` works with both data.frames and matrices.
This is because `rbind` is a generic function with a default method that
works with matrices and a data.frame method that works with data.frames. Similar
to `rbind`, if rownames of value are not given and row.nm
is left NULL, then the rownames of the return object are automatically created
and can be dissatisfying.
Value
Like other similar functions (e.g., `names<-` and `[<-`),
`rbind<-` does not appear to have a return object. However, it technically
does as a side effect. The argument data will have been changed such that
value has been added as rows. If a traditional return object is desired,
and no side effects, then it can be called like a traditional function:
dat2 <- 'rbind<-'(dat1, value = add1).
Examples
attitude2 <- attitude
rbind(attitude2) <- colMeans(attitude2) # defaults to rownames = as.character(nrow(`data`) + 1)
attitude2 <- attitude2[!(`%in%`(x = row.names(attitude2), table = "31")), ] # logical subset
rbind(attitude2, row.nm = "mean") <- colMeans(attitude2)
attitude2 <- attitude2[-1*(match(x = "mean", table = row.names(attitude2))), ] # position subset
rbind(attitude2, after = "10", row.nm = c("mean","sum")) <-
rbind(colMeans(attitude2), colSums(attitude2)) # `value` as a matrix
attitude2 <- attitude2[grep(pattern = "mean|sum", x = row.names(attitude2),
invert = TRUE), ] # rownames subset
attitude2 <- `rbind<-`(data = attitude2, value = colMeans(attitude2)) # traditional call
attitude2 <- as.matrix(attitude, rownames.force = TRUE) # as.matrix.data.frame
rbind(attitude2, after = "10", row.nm = "mean") <- colMeans(attitude2) # `data` as a matrix
# using overwrite
mtcars2 <- mtcars
rownames(mtcars2)
add <- mtcars[c("Mazda RX4","Mazda RX4 Wag","Datsun 710"), ]*11
rbind(mtcars2, overwrite = TRUE) <- add
mtcars2 <- mtcars
rbind(mtcars2, overwrite = FALSE) <- add
R Package Documentation
Browse R Packages
We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
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