Ternary Coordinates

Computes ternary coordinates.

Usage

coordinates_ternary(x, y, z, ...)

# S4 method for numeric,numeric,numeric
coordinates_ternary(x, y, z, missing = getOption("isopleuros.missing"))

# S4 method for ANY,missing,missing
coordinates_ternary(x, missing = getOption("isopleuros.missing"))

Arguments

x, y, z

A numeric vector giving the x, y and z cartesian coordinates of a set of points. If y and z are missing, an attempt is made to interpret x in a suitable way (see grDevices::xyz.coords()).

...

Currently not used.

missing

A logical scalar: should missing values be replaced with zeros before the computation proceeds? If FALSE (the default), incomplete cases are removed.

Value

A list.

See also

Other coordinates: coordinates_cartesian()

Author

N. Frerebeau

Examples

## Compositional data
coda <- data.frame(
  x = c(1, 0, 0, 1/3),
  y = c(0, 1, 0, 1/3),
  z = c(0, 0, 1, 1/3)
)

## Ternary coordinates
(tern <- coordinates_ternary(coda))
#> $x
#> [1] 0.0 1.0 0.5 0.5
#> 
#> $y
#> [1] 0.0000000 0.0000000 0.8660254 0.2886751
#> 

## Cartesian coordinates
(cart <- coordinates_cartesian(tern))
#> $x
#> [1] 1.0000000 0.0000000 0.0000000 0.3333333
#> 
#> $y
#> [1] 0.0000000 1.0000000 0.0000000 0.3333333
#> 
#> $z
#> [1] 0.0000000 0.0000000 1.0000000 0.3333333
#>