R: Examples for 'graphics::axTicks'

### ** Examples

 plot(1:7, 10*21:27)

plot of chunk example-graphics-axTicks-1

 axTicks(1)

[1] 1 2 3 4 5 6 7

 axTicks(2)

[1] 210 220 230 240 250 260 270

 stopifnot(identical(axTicks(1), axTicks(3)),
           identical(axTicks(2), axTicks(4)))

## Show how axTicks() and axis() correspond :
op <- par(mfrow = c(3, 1))
for(x in 9999 * c(1, 2, 8)) {
    plot(x, 9, log = "x")
    cat(formatC(par("xaxp"), width = 5),";", T <- axTicks(1),"\n")
    rug(T, col =  adjustcolor("red", 0.5), lwd = 4)
}

 1000 1e+05     3 ; 200 500 1000 2000 5000 10000 20000 50000 1e+05 2e+05 5e+05

 1000 1e+06     2 ; 500 1000 5000 10000 50000 1e+05 5e+05 1e+06

 1000 1e+07     1 ; 1000 10000 1e+05 1e+06 1e+07

par(op)

x <- 9.9*10^(-3:10)
plot(x, 1:14, log = "x")

axTicks(1) # now length 7, in R <= 2.13.x gave 'nintLog = Inf' res; then

[1] 1e-02 1e+00 1e+02 1e+04 1e+06 1e+08 1e+10

## 1e-01 1e+01 1e+03 1e+05 1e+07 1e+09 1e+11 ; since R 4.2.0: 1e-2 1e0 1e2 .. 1e10
axTicks(1, nintLog = Inf) # rather too many

 [1] 1e-02 1e-01 1e+00 1e+01 1e+02 1e+03 1e+04 1e+05 1e+06 1e+07 1e+08 1e+09
[13] 1e+10 1e+11

## An example using axTicks() without reference to an existing plot
## (copying R's internal procedures for setting axis ranges etc.),
## You do need to supply _all_ of axp, usr, log, nintLog
## standard logarithmic y axis labels
ylims <- c(0.2, 88)
get_axp <- function(x) 10^c(ceiling(x[1]), floor(x[2]))
## mimic par("yaxs") == "i"
usr.i <- log10(ylims)
(aT.i <- axTicks(side = 2, usr = usr.i,
                 axp = c(get_axp(usr.i), n = 3), log = TRUE, nintLog = 5))

[1]  0.2  0.5  1.0  2.0  5.0 10.0 20.0 50.0

## mimic (default) par("yaxs") == "r"
usr.r <- extendrange(r = log10(ylims), f = 0.04)
(aT.r <- axTicks(side = 2, usr = usr.r,
                 axp = c(get_axp(usr.r), 3), log = TRUE, nintLog = 5))

[1]   0.2   0.5   1.0   2.0   5.0  10.0  20.0  50.0 100.0

## Prove that we got it right :
plot(0:1, ylims, log = "y", yaxs = "i")

stopifnot(all.equal(aT.i, axTicks(side = 2)))

plot(0:1, ylims, log = "y", yaxs = "r")

stopifnot(all.equal(aT.r, axTicks(side = 2)))

Examples for 'graphics::axTicks'

Compute Axis Tickmark Locations