coord_tern {ggtern}

Ternary Coordinate System

Description

coord_tern is a function which creates a transformation mechanism between the ternary system, and, the cartesian system. It inherits from the fixed coordinate system, employing fixed ratio between x and y axes once transformed.

Usage

coord_tern(Tlim = NULL, Llim = NULL, Rlim = NULL, expand = TRUE)

Arguments

Tlim

the range of T in the ternary space

Llim

the range of L in the ternary space

Rlim

the range of R in the ternary space

expand

If TRUE, the default, adds a small expansion factor to the limits to ensure that data and axes don't overlap. If FALSE, limits are taken exactly from the data or xlim/ylim.

Value

coord_tern returns a CoordTern ggproto

Aesthetics (Required in Each Layer)

coord_ternunderstands the following aesthetics (required aesthetics are in bold):

• x

• y

• z

Abovementioned limitations include the types of geometries which can be used (ie approved geometries), or modifications to required aesthetic mappings. One such essential patch is, for approved geometries previously requiring x and y coordinates, now require an additional z coordinate, and, geom_segment goes one step further in that it requires both an additional z and zend coordinate mappings.

In essence, the required aesthetics are the product between what is required of each 'layer' and what is required of the 'coordinate system'.

Author(s)

Nicholas Hamilton