RcppAlgos (version 2.9.3)

expandGridIter: expandGrid Iterator

Description

• Returns an iterator for iterating over the Cartesian product of the input vectors.

• Supports random access via the [[ method.

• GMP support allows for exploration of cases where the number of products is large.

• Use the next methods to obtain results in lexicographical order.

Usage

expandGridIter(..., nThreads = NULL, return_df = FALSE)

Value

• If nextIter is called, a named vector is returned if a matrix can be returned in the general case. Otherwise, a data.frame is returned.

• When nextNIter and nextRemaining are called, a named matrix is returned when all of the input is of the same type and return_df = FALSE. Otherwise, a data.frame is returned.

Arguments

...

vectors, factors or a list containing these. (See ?expand.grid).

nThreads

Specific number of threads to be used. The default is NULL.

return_df

Logical flag to force the output to be a data.frame. The default is FALSE.

Author

Joseph Wood

Details

Once you initialize a new iterator, the following methods are available:

nextIter

Retrieve the next lexicographical result

nextNIter

Pass an integer n to retrieve the next n lexicographical results

nextRemaining

Retrieve all remaining lexicographical results

currIter

Returns the current iteration

startOver

Resets the iterator

sourceVector

View the source input

summary

Returns a list of summary information about the iterator

front

Retrieve the first lexicographical result

back

Retrieve the last lexicographical result

[[

Random access method. Pass a single value or a vector of valid indices. If a single value is passed, the internal index of the iterator will be updated, however if a vector is passed the internal state will not change. GMP support allows for flexible indexing.

See Also

expandGrid

Examples

a = expandGridIter(factor(state.abb), euro, islands)
a@nextIter()
a@nextNIter(3)
a@front()
all_remaining = a@nextRemaining()
dim(all_remaining)
a@summary()
a@back()
a[[5]]
a@summary()
a[[c(1, 17, 3)]]
a@summary()