Common higher-order functions in functional programming languages
Reduce uses a binary function to successively combine the
elements of a given list-like or vector-like object and a possibly
given initial value.
Filter extracts the elements of a list-like or vector-like
object for which a predicate (logical) function gives true.
Find and Position give the first or last such element
and its position in the object, respectively.
Map applies a function to the corresponding elements of given
list-like or vector-like objects.
NOTE: This man page is for the Reduce, Filter,
Find, Map and Position S4 generic functions
defined in the BiocGenerics package.
See ?base::Reduce 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.
Reduce(f, x, init, right=FALSE, accumulate=FALSE) Filter(f, x) Find(f, x, right=FALSE, nomatch=NULL) Map(f, ...) Position(f, x, right=FALSE, nomatch=NA_integer_)
f, init, right, accumulate, nomatch |
See |
x |
A list-like or vector-like object. |
... |
One or more list-like or vector-like objects. |
See ?base::Reduce for the value returned by the
default methods.
Specific methods defined in Bioconductor packages should behave as consistently as possible with the default methods.
base::Reduce for the default Reduce,
Filter, Find, Map and Position methods.
showMethods for displaying a summary of the
methods defined for a given generic function.
selectMethod for getting the definition of
a specific method.
Reduce,List-method in the S4Vectors package
for an example of a specific Reduce method (defined for
List objects).
BiocGenerics for a summary of all the generics defined in the BiocGenerics package.
Reduce # note the dispatch on the 'x' arg only
showMethods("Reduce")
selectMethod("Reduce", "ANY") # the default method
Filter # note the dispatch on the 'x' arg only
showMethods("Filter")
selectMethod("Filter", "ANY") # the default method
Find # note the dispatch on the 'x' arg only
showMethods("Find")
selectMethod("Find", "ANY") # the default method
Map # note the dispatch on the '...' arg only
showMethods("Map")
selectMethod("Map", "ANY") # the default method
Position # note the dispatch on the 'x' arg only
showMethods("Position")
selectMethod("Position", "ANY") # the default methodPlease choose more modern alternatives, such as Google Chrome or Mozilla Firefox.