iseq: Iterators for sequence generation In itertools2: itertools2: Functions creating iterators for efficient looping

Description

Constructs iterators that generate regular sequences that follow the `seq` family.

Usage

 ```1 2 3 4 5 6``` ```iseq(from = 1, to = 1, by = (to - from)/(length_out - 1), length_out = NULL, along_with = NULL) iseq_len(length_out = NULL) iseq_along(along_with = NULL) ```

Arguments

 `from` the starting value of the sequence `to` the end value of the sequence `by` increment of the sequence. `length_out` desired length of the sequence. A non-negative number, which for `seq` will be rounded up if fractional. `along_with` the length of the sequence will match the length of this argument

Details

The `iseq` function generates a sequence of values beginning with `from` and ending with `to`. The sequence of values between are determined by the `by`, `length_out`, and `along_with` arguments. The `by` argument determines the step size of the sequence, whereas `length_out` and `along_with` determine the length of the sequence. If `by` is not given, then it is determined by either `length_out` or `along_with`. By default, neither are given, in which case `by` is set to 1 or -1, depending on whether ```to > from```.

`seq_along` and `seq_len` return an iterator, which generates a sequence of integers, beginning with 1 and proceeding to an ending value

Value

sequence's iterator

Examples

 ```1 2 3 4 5 6 7 8``` ```it <- iseq(from=2, to=5) unlist(as.list(it)) == 2:5 it2 <- iseq_len(4) unlist(as.list(it2)) == 1:4 it3 <- iseq_along(iris) unlist(as.list(it3)) == 1:length(iris) ```

itertools2 documentation built on May 30, 2017, 7:17 a.m.