Sequences: duration

This is a duration method for the seq() generic.

Using seq() on duration objects always retains the type of from.

When calling seq(), exactly two of the following must be specified:

• to

• by

• Either length.out or along.with

Usage

# S3 method for class 'clock_duration'
seq(from, to = NULL, by = NULL, length.out = NULL, along.with = NULL, ...)

Arguments

from

[clock_duration(1)]

A duration to start the sequence from.

to

[clock_duration(1) / NULL]

A duration to stop the sequence at.

to is cast to the type of from.

to is only included in the result if the resulting sequence divides the distance between from and to exactly.

by

[integer(1) / clock_duration(1) / NULL]

The unit to increment the sequence by.

If by is an integer, it is transformed into a duration with the precision of from.

If by is a duration, it is cast to the type of from.

length.out

[positive integer(1) / NULL]

The length of the resulting sequence.

If specified, along.with must be NULL.

along.with

[vector / NULL]

A vector who's length determines the length of the resulting sequence.

Equivalent to length.out = vec_size(along.with).

If specified, length.out must be NULL.

...

These dots are for future extensions and must be empty.

Value

A sequence with the type of from.

Details

If from > to and by > 0, then the result will be length 0. This matches the behavior of rlang::seq2(), and results in nicer theoretical properties when compared with throwing an error. Similarly, if from < to and by < 0, then the result will also be length 0.

Examples

seq(duration_days(0), duration_days(100), by = 5)
#> <duration<day>[21]>
#>  [1] 0   5   10  15  20  25  30  35  40  45  50  55  60  65  70  75  80 
#> [18] 85  90  95  100

# Using a duration `by`. Note that `by` is cast to the type of `from`.
seq(duration_days(0), duration_days(100), by = duration_weeks(1))
#> <duration<day>[15]>
#>  [1] 0  7  14 21 28 35 42 49 56 63 70 77 84 91 98

# `to` is cast from 5 years to 60 months
# `by` is cast from 1 quarter to 4 months
seq(duration_months(0), duration_years(5), by = duration_quarters(1))
#> <duration<month>[21]>
#>  [1] 0  3  6  9  12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 57 60

seq(duration_days(20), by = 2, length.out = 5)
#> <duration<day>[5]>
#> [1] 20 22 24 26 28