logVals: Create log-axis values and labels

In berryFunctions: Function Collection Related to Plotting and Hydrology

Create log-axis values and labels

Description

Create nice values and labels to write at logarithmic axes

Usage

logVals(
  from = -7,
  to = 7,
  Range,
  base = 1,
  big.mark = "'",
  decimal.mark = ".",
  scientific = FALSE,
  exponent = Inf,
  expobase1 = FALSE,
  allbase = 1:9,
  ...
)

Arguments

from	Lower exponent OR vector with data
to	High end
Range	Or give from and to as range
base	Bases to be used, eg. c(1,2,5). Use base=NA to switch between 1 and c(1,2,5) depending on range. DEFAULT 1
big.mark	Symbol separating thousands, eg. space, comma, dot, etc. see format and prettyNum
decimal.mark	Character separating comma values, see format and prettyNum
scientific	See format
exponent	Starting at which exponent should labs be an expression with exponents? Compare to options("scipen"). This is mainly for logAxis and only for base 1. DEFAULT: Inf
expobase1	Should "n * " be appended before 10^exp if n=1? DEFAULT: FALSE
allbase	Base for $all (for horizontal lines). DEFAULT: 1:9
...	Ignored arguments

Value

A list with

vals	Values for lines and label positions
labs	Formatted values for labels
all	Values for lines

Author(s)

Berry Boessenkool, [e-mail], Feb 2014

See Also

log10, logAxis, https://web.archive.org/web/20190504213250/https://r.789695.n4.nabble.com/expression-exponent-labeling-td4661174.html

Examples

# Easiest use: vector with data (logVals automatically finds range):
y <- 10^runif(50, -1, 2)
plot(y, log="y") # not much control over placement and format of labels
plot(y, log="y", yaxt="n")
# now do this better, with custom bases:
lv <- logVals(y, base=c(1,2,5) )
axis(2, lv$vals, lv$labs, las=1)

# Default arguments:
lv <- logVals()
str(lv) # values, formatted labels, all 10^x values for lines
plot(1, ylim=c(1e-3, 1e4), log="y", yaxt="n", yaxs="i")
abline(h=lv$all, col=8 )
box("plot")
axis(2, lv$vals, lv$labs, las=1)
lines(seq(0.5, 1.5, len=50), 10^runif(50, -3, 4), col=2)

# Formatting labels:
logVals(                )$labs
logVals(scient=TRUE     )$labs
logVals(exponent=5      )$labs # expression with exponent, see logAxis
logVals(big.mark=" "    )$labs
logVals(big=".", dec=",")$labs # German style (not recommended)

berryFunctions documentation built on May 29, 2024, 4:01 a.m.