trans_loglinear {mtb}

Transformation for continuous data with a finite number of distinct values

Description

trans_loglinear() derives a log transformation from a numerical vector with a smaller number (ideally < 30) of distinct values.. The return can be used with function ggplot::scale_x_continuous() or ggplot::scale_y_continuous() to create a desired axis.

Usage

trans_loglinear(x = NULL, nb = 30, int = NA, scale = NA, mindist = 0.03)

Arguments

x

A numerical vector used in a plot as (typically) x

nb

An integer for the maximum number of breaks. Default=30

int

One of

• NA for a value calculated automatically

• A real number (>=0) for the shift before log transform

scale

One of

• NA for a value calculated automatically

• A real number (>0) for the scale before log transform

mindist

One of

• NA for a default value set to 0.03

• A real number between 0 and 0.2 for the minimum distance ratio between major ticks

Value

A transformation function

Examples

library(ggplot2)
pdt=data.frame(x=rep(c(0.5, 1, 10,11,12, 100, 1000), each=5))
pdt$y=pdt$x+rnorm(length(pdt$x))
t=trans_loglinear(pdt$x)
ggplot(pdt, aes(x=x, y=y))+geom_point()+scale_x_continuous(trans=t)