R: Barycentric plots

tritrafo {klaR} | R Documentation

## Barycentric plots

### Description

Function to carry out the transformation into 2D space for `triplot`, `trilines` etc.

### Usage

    tritrafo(x, y = NULL, z = NULL, check = TRUE, tolerance = 0.0001)

### Arguments

`x` | Vector of fractions of first component OR 3-column matrix containing all three components (omitting `y` and `z`) OR 3-element vector (for all three components, omitting `y` and `z`).
`y` | (optional) vector of fractions of second component.
`z` | (optional) vector of fractions of third component.
`check` | if `TRUE`, it is checked whether `x+y+z=1` and `x,y,z>=0` for all cases.
`tolerance` | tolerance for above sum check.

### Details

Projects the mixture given by `x`, `y`, and `z` with `x`, `y`, `z` between one and zero and `x+y+z=1` into a two-dimensional space.

For further details see `triplot`.

### Value

A matrix with two columns corresponding to the two dimensions.

### Author(s)

Christian Röver, roever@statistik.tu-dortmund.de

### See Also

`triplot`, `tripoints`, `trilines`, `trigrid`

### Examples

    tritrafo(0.1, 0.2, 0.7)
    tritrafo(0.1, 0.2, 0.6) # warning

    triplot()
    points(tritrafo(0.1, 0.2, 0.7), col="red")
    tripoints(0.1, 0.2, 0.7, col="green")  # the same

    tritrafo(c(0.1,0.2), c(0.3,0.4), c(0.6,0.4))
    tritrafo(diag(3))

    point <- c(0.25,0.6,0.15)
    triplot(point, pch=16)
    text(tritrafo(point), "(0.25, 0.60, 0.15)", adj=c(0.5,2)) # add a label

[Package klaR version 0.6-12 Index]