QTS Sample Class

A collection of functions that implements the QTS sample class. It currently provides the as_qts_sample() function for QTS sample coercion of lists of qts objects, the is_qts_sample() function for checking if an object is a QTS sample and the subset operator.

Usage

as_qts_sample(x)

is_qts_sample(x)

# S3 method for qts_sample
[(x, i, simplify = FALSE)

Arguments

x

A list of tibble::tibbles, each of which with columns time, w, x, y and z.

i

A valid expression to subset observations from a QTS sample.

simplify

A boolean value specifying whether the resulting subset should be turned into a single QTS in case the subset is of size 1. Defaults to FALSE.

Value

An object of class qts_sample.

Details

A QTS sample is a collection of quaternion time series (QTS), each of which is stored as a tibble::tibble with 5 columns:

• time: A first column specifying the time points at which quaternions were collected;

• w: A second column specifying the first coordinate of the collected quaternions;

• x: A third column specifying the second coordinate of the collected quaternions;

• y: A fourth column specifying the third coordinate of the collected quaternions;

• z: A fifth column specifying the fourth coordinate of the collected quaternions.

Examples

x <- vespa64$igp
y <- as_qts_sample(x)
is_qts_sample(x)
#> [1] TRUE
is_qts_sample(y)
#> [1] TRUE
x[1]
#> [[1]]
#> # A tibble: 101 × 5
#>     time         w         x         y         z
#>    <int> <dec:.5!> <dec:.5!> <dec:.5!> <dec:.5!>
#>  1     0   0.99427   0.07973   0.06988   0.01334
#>  2     1   0.99483   0.07457   0.06763   0.01313
#>  3     2   0.99542   0.06931   0.06457   0.01269
#>  4     3   0.99602   0.06398   0.06091   0.01184
#>  5     4   0.99652   0.05949   0.05742   0.01070
#>  6     5   0.99694   0.05572   0.05403   0.00932
#>  7     6   0.99729   0.05275   0.05079   0.00772
#>  8     7   0.99757   0.05056   0.04761   0.00583
#>  9     8   0.99782   0.04883   0.04430   0.00366
#> 10     9   0.99805   0.04730   0.04071   0.00125
#> # ℹ 91 more rows
#> 
#> attr(,"class")
#> [1] "qts_sample" "list"      
x[1, simplify = TRUE]
#> # A tibble: 101 × 5
#>     time         w         x         y         z
#>    <int> <dec:.5!> <dec:.5!> <dec:.5!> <dec:.5!>
#>  1     0   0.99427   0.07973   0.06988   0.01334
#>  2     1   0.99483   0.07457   0.06763   0.01313
#>  3     2   0.99542   0.06931   0.06457   0.01269
#>  4     3   0.99602   0.06398   0.06091   0.01184
#>  5     4   0.99652   0.05949   0.05742   0.01070
#>  6     5   0.99694   0.05572   0.05403   0.00932
#>  7     6   0.99729   0.05275   0.05079   0.00772
#>  8     7   0.99757   0.05056   0.04761   0.00583
#>  9     8   0.99782   0.04883   0.04430   0.00366
#> 10     9   0.99805   0.04730   0.04071   0.00125
#> # ℹ 91 more rows