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BiocGenerics (version 0.18.0)

lapply: 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

X
A list-like or vector-like object.
FUN, ..., simplify, USE.NAMES
See ?base::lapply for a description of these 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

Run this code
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

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