Apply a function over a list-like or vector-like object

Description

lapply returns a list of the same length as X, each element of which is the result of applying FUN to the corresponding element of X.

sapply is a user-friendly version and wrapper of lapply by default returning a vector, matrix or, if simplify="array", an array if appropriate, by applying simplify2array(). sapply(x, f, simplify=FALSE, USE.NAMES=FALSE) is the same as lapply(x, f).

NOTE: This man page is for the lapply and sapply S4 generic functions defined in the BiocGenerics package. See ?base::lapply for the default methods (defined in the base package). Bioconductor packages can define specific methods for objects (typically list-like or vector-like) not supported by the default methods.

Usage

lapply(X, FUN, ...)
sapply(X, FUN, ..., simplify=TRUE, USE.NAMES=TRUE)

Arguments

Value

See ?base::lapply for the value returned by the default methods.

Specific methods defined in Bioconductor packages should behave as consistently as possible with the default methods. In particular, lapply and sapply(simplify=FALSE) should always return a list.

See Also

• base::lapply for the default lapply and sapply methods.

• showMethods for displaying a summary of the methods defined for a given generic function.

• selectMethod for getting the definition of a specific method.

• lapply,List-method in the S4Vectors package for an example of a specific lapply method (defined for List objects).

• BiocGenerics for a summary of all the generics defined in the BiocGenerics package.

Examples

lapply  # note the dispatch on the 'X' arg only
showMethods("lapply")
selectMethod("lapply", "ANY")  # the default method

sapply  # note the dispatch on the 'X' arg only
showMethods("sapply")
selectMethod("sapply", "ANY")  # the default method