logtix: Add Log-Scaled Tick Marks to an Axis

In mwrowe/microRutils: Mike Rowe's Miscellaneous R Utility Functions

Description

logtix() labels tick marks on a log-scaled axis at regular intervals with untransformed (linear scale) values.

Usage

logtix(
  axis = 1:2,
  major = "^(|[0\\.]+)[125]",
  plus1 = TRUE,
  base = 10,
  las = 1,
  tcl = c(-0.2, -0.1),
  plot.tix = T,
  usr,
  ticfun = function(x) x,
  labels = TRUE,
  ...
)

Arguments

axis	Numeric vector of axes to label, accepts values in 1:4.
major	Character value with regular expression indicating which ticks should should be labelled (major ticks); default will label tick marks. Default is "^(|[0\.]+)[125]" where the (linear-scale) number starts with 1, 2 or 5. Set to "" to omit tick labels.
plus1	Logical or numeric value; are values plotted as log10(x+1)? If plus1 is a value other than 0 or 1, transform as log10(x+plus1).
base	Numeric values; logarithmic base. Default is 10, use exp(1) for natural log.
las	Value specifying rientation of the tick labels– see help("par").
tcl	Numeric vector of major (tcl[1]) and minor (tcl[2]) tick lengths. Provide a single number to use the same for both major and minor.
plot.tix	logical; should the ticks be added to the current plot?.
usr	2-element numeric vector specifying axis limits; used in conjunction with ticfun to apply transformations to the axis.
ticfun	Function to map axis scales (see Notes).
labels	Logical; should tick marks be labelled at all?
...	Other arguments passed to the axis function.

Details

This function enables the user to label the axes of a plot that was generated using log-transformed data (including the case where a constant was added prior to log transformation), where the tick marks are labeled with "raw" (untransformed) values.

The usr and ticfun arguments were added to permit this function to be used with plots generated by the Hist function, by passing in the xbin or ybin function returned as an element of the list generated by Hist. This is necessary because the values of the axis generated by Hist are based on the number, width and spacing of bins, not the original data scale.

Value

Returns a list object which may have $x and $y elements, each with a named numeric vector of tick marks (on the plot scale) and labels (on linear scale) for both major and minor ticks.

Author(s)

M.W.Rowe, [e-mail]

See Also

par, axis for more details about plotting options.

mwrowe/microRutils documentation built on June 12, 2021, 2:41 p.m.