Tolerance Ellipses

Plots tolerance ellipses.

Usage

viz_tolerance(x, y, ...)

wrap_tolerance(x, y, ...)

# S4 method for class 'numeric,numeric'
viz_tolerance(
  x,
  y,
  ...,
  group = NULL,
  level = 0.95,
  color = NULL,
  fill = FALSE,
  symbol = FALSE
)

# S4 method for class 'MultivariateAnalysis,missing'
viz_tolerance(
  x,
  ...,
  group = NULL,
  level = 0.95,
  color = NULL,
  fill = FALSE,
  symbol = FALSE
)

# S4 method for class 'MultivariateBootstrap,missing'
viz_tolerance(
  x,
  ...,
  level = 0.95,
  color = FALSE,
  fill = FALSE,
  symbol = FALSE
)

# S4 method for class 'PCOA,missing'
viz_tolerance(
  x,
  ...,
  group = NULL,
  level = 0.95,
  color = NULL,
  fill = FALSE,
  symbol = FALSE
)

# S4 method for class 'numeric,numeric'
wrap_tolerance(x, y, group = NULL, level = 0.95)

# S4 method for class 'MultivariateAnalysis,missing'
wrap_tolerance(
  x,
  margin = 1,
  axes = c(1, 2),
  group = NULL,
  level = 0.95,
  principal = TRUE
)

# S4 method for class 'PCOA,missing'
wrap_tolerance(x, axes = c(1, 2), group = NULL, level = 0.95)

Arguments

x, y

A numeric vector. If y is missing, x must be an object from which to wrap observations (a CA, MCA or PCA object).

...

Further graphical parameters to be passed to graphics::polygon().

group

A vector specifying the group an observation belongs to.

level

A numeric vector specifying the confidence/tolerance level.

color

The colors for borders (will be mapped to group). Ignored if set to FALSE. If NULL, the default color scheme will be used.

fill

The background colors (will be mapped to group). Ignored if set to FALSE.

symbol

A vector of symbols (will be mapped to group). Ignored if set to FALSE.

margin

A length-one numeric vector giving the subscript which the data will be returned: 1 indicates individuals/rows (the default), 2 indicates variables/columns.

axes

A length-two numeric vector giving the dimensions for which to compute results.

principal

A logical scalar: should principal coordinates be used? If FALSE, standard coordinates are returned.

Value

wrap_tolerance() returns a data.frame of envelope x and y coordinates. An extra column named group is added specifying the group an observation belongs to.

viz_tolerance()is called for its side-effects: it results in a graphic being displayed. Invisibly returns x.

See also

Other envelopes: viz_confidence(), viz_ellipses(), viz_hull()

Author

N. Frerebeau

Examples

## Load data
data("iris")

## Compute principal components analysis
X <- pca(iris, scale = TRUE, sup_quali = "Species")

## Compute tolerance ellipse coordinates
conf <- wrap_confidence(X, margin = 1, group = "Species", level = 0.95)

## Plot tolerance ellipses
col <- c("#004488", "#DDAA33", "#BB5566")
viz_rows(X, extra_quali = iris$Species, color = col)
viz_tolerance(X, group = iris$Species, color = col, level = 0.95)