Last data update: 2014.03.03
R: Simplex visualization
simplexplot R Documentation
Simplex visualization
Description
The stochastic nature of the alpha coefficients implies
that they exist on a standard (K-1)-simplex with the K
archetypes Z as the corners, and the coefficients as the
coordinate with respect to these corners. A standard
simplex can be projected to two dimensions via a skew
orthogonal projection, where all the vertices of the
simplex are shown on a circle connected by edges. The
individual alpha coefficients can be then projected into
this circle.
Usage
simplexplot(object, radius = 10, order = NULL, labels_cex = 1,
labels = NULL, show_labels = TRUE, points_col = "#00000044",
points_pch = 19, points_cex = 1, projection = simplex_projection,
show_points = TRUE, show_circle = TRUE, circle_col = "lightgray",
show_edges = TRUE, edges_col = "lightgray", show_direction = FALSE,
direction_length = 1, directions_col = points_col, ...)
Arguments
object
An archetypes
object
radius
Radius of the projection
order
Order of the archetypes
labels_cex
Label expansion
labels
Labels
show_labels
Show labels
points_col
Color of the points
points_pch
Plot character of the points
points_cex
Character expansion of the points
projection
Projection function; see
archmap_projections
show_points
Show the points
show_circle
Show the circle
circle_col
Color of the circle
show_edges
Show the edges
edges_col
Color of the edges
direction_length
Expansion of the direction
pointers
directions_col
Color of the direction pointers
show_direction
Show direction pointers
...
Additional arguments; currently ignored
Value
Invisible list of all computed components needed for the
simplex visualization.
References
See Section 6 in "Probabilistic Archetypal Analysis" by
Seth and Eugster (2014), http://arxiv.org/abs/1312.7604.
Examples
### This example reproduces parts of the Figure 7 shown in
### "Probabilistic Archetypal Analysis" by Seth and Eugster (2014)
data("toy", package = "archetypes")
set.seed(1234); a3 <- archetypes(toy, k = 3)
set.seed(1237); a4 <- archetypes(toy, k = 4)
set.seed(1238); a5 <- archetypes(toy, k = 5)
simplexplot(a3)
simplexplot(a3, show_direction = TRUE, show_points = FALSE)
simplexplot(a4, projection = tspsimplex_projection)
simplexplot(a5, show_direction = TRUE, show_points = FALSE,
direction_length = 2, directions_col = "black")
Results