QTS Transformation to Angular Velocity Vector Time Series

This function projects a quaternion time series into the space of angular velocity vectors.

Usage

qts2avvts(x, spar = 0)

Arguments

x

An object of class qts.

spar

smoothing parameter, typically (but not necessarily) in \((0,1]\). When spar is specified, the coefficient \(\lambda\) of the integral of the squared second derivative in the fit (penalized log likelihood) criterion is a monotone function of spar, see the details below. Alternatively lambda may be specified instead of the scale free spar=\(s\).

Value

A time series stored as a tibble::tibble with columns time, x, y and z containing the angular velocity vector at each time point.

Examples

qts2avvts(vespa64$igp[[1]])
#> # A tibble: 101 × 4
#>     time        x        y         z
#>    <int>    <dbl>    <dbl>     <dbl>
#>  1     0 -0.0109  -0.00444 -0.000474
#>  2     1 -0.0103  -0.00519 -0.000562
#>  3     2 -0.0109  -0.00700 -0.00129 
#>  4     3 -0.00994 -0.00728 -0.00201 
#>  5     4 -0.00832 -0.00690 -0.00255 
#>  6     5 -0.00674 -0.00664 -0.00298 
#>  7     6 -0.00514 -0.00640 -0.00349 
#>  8     7 -0.00383 -0.00642 -0.00405 
#>  9     8 -0.00313 -0.00692 -0.00463 
#> 10     9 -0.00324 -0.00747 -0.00496 
#> # ℹ 91 more rows