tourr (version 1.1.0)

guided_section_tour: A guided section tour path.

Description

The guided section tour is a variation of the guided tour that is using a section pursuit index for the selection of target planes.

Usage

guided_section_tour(
  index_f,
  d = 2,
  alpha = 0.5,
  cooling = 0.99,
  max.tries = 25,
  max.i = Inf,
  v_rel = NULL,
  anchor = NULL,
  search_f = search_geodesic,
  ...
)

Arguments

index_f

the section purusit index function to optimise. The function needs to take three arguments, the projected data, the vector of distances from the current projection plane, and the slice thickness h.

d

target dimensionality

alpha

the initial size of the search window, in radians

cooling

the amount the size of the search window should be adjusted by after each step

max.tries

the maximum number of unsuccessful attempts to find a better projection before giving up

max.i

the maximum index value, stop search if a larger value is found

v_rel

relative volume of the slice. If not set, suggested value is caluclated and printed to the screen.

anchor

A vector specifying the reference point to anchor the slice. If NULL (default) the slice will be anchored at the data center.

search_f

the search strategy to use

...

arguments sent to the search_f

Details

Usually, you will not call this function directly, but will pass it to a method that works with tour paths like animate_slice, save_history or render.

See Also

slice_index for an example of an index functions. search_geodesic, search_better, search_better_random for different search strategies

Examples

# Generate samples on a 3d hollow sphere using the geozoo package
set.seed(12345)
sphere3 <- geozoo::sphere.hollow(3)$points
# Columns need to be named before launching the tour
colnames(sphere3) <- c("x1", "x2", "x3")
# Off-center anchoring
anchor3 <- matrix(rep(0.75, 3), ncol=3)
# Index setup
r_breaks <- linear_breaks(5, 0, 1)
a_breaks <- angular_breaks(10)
eps <- estimate_eps(nrow(sphere3), ncol(sphere3), 0.1 / 1, 5 * 10, 10, r_breaks)
idx <- slice_index(r_breaks, a_breaks, eps, bintype = "polar", power = 1, reweight = TRUE, p = 3)
# Running the guided section tour select sections showing a big hole in the center
animate_slice(sphere3, guided_section_tour(idx, v_rel = 0.1, anchor = anchor3, max.tries = 5),
  v_rel = 0.1, anchor = anchor3
)