Nothing
#' @title Compute Pretty Minor Axis Tick Scales
#'
#' @description Compute pretty mark locations for minor ticks, based on the way
#' that traditional R graphics do it.
#'
#' @param usr the user coordinates of the minimum and maximum limits of the axis
#' @param n the number of intervals defined by the minor ticks
#' @param at.maj the positions at which major tick-marks are to be drawn.
#' By default (when NULL) tickmark locations are computed buy the axisTicks
#' function
#' @param extend whether to add minor ticks even outside the major ticks
#' (T) or not (F)
#'
#' @seealso \code{\link{minorAxis}}, \code{\link{seq_log}}
#'
#' This function is based on \code{\link{every_nth}}, which suppresses values
#' every multiple of a given number.
#'
#' @examples
#' minorAxisTicks(usr = c(-20, 620), n = 10)
#'
#' @importFrom grDevices axisTicks
#' @export
#'
minorAxisTicks <- function(usr, n = NULL, at.maj = NULL, extend = T)
{
if(is.null(at.maj)) {
at.maj <- axisTicks(usr, log = F)
} else {
r1 <- at.maj - min(usr)
r2 <- at.maj - max(usr)
p1 <- which.min(abs(r1))
p2 <- which.min(abs(r2))
if(!(abs(r1[p1]/min(usr)) < 1.5e-8) & r1[p1] < 0 &
p1 != length(at.maj)) p1 <- p1 + 1
if(!(abs(r2[p2]/max(usr)) < 1.5e-8) & r2[p2] > 0 &
p2 != 1) p2 <- p2 - 1
at.maj <- at.maj[p1:p2]
}
# Give at.min when n is NULL or 1----
if(is.null(n)){
res <- list(at.maj)
} else {
# Work the minor ticks: check regularity ----
mina <- min(at.maj, na.rm = T)
maxa <- max(at.maj, na.rm = T)
difa <- maxa - mina
na <- difa / (length(at.maj) - 1)
# Checks----
sia <- seq(mina,maxa,by = na)
if(!isTRUE(all.equal(sort(sia),sort(at.maj)))) {
stop("at.maj should be regularly spaced and sorted")
}
if(!(is.numeric(n) & length(n) == 1)){
stop("n should be a numeric of length one")
}
# Work it ----
tick.pos <- c(mina,maxa,difa/na)
nat.int <- (tick.pos[2] - tick.pos[1])/tick.pos[3]
# Define the position of minor ticks ----
distance.between.minor <- nat.int/n
p <- seq(min(at.maj), max(at.maj), by = distance.between.minor)
q <- sort(every_nth(p,n,empty=FALSE))
# Extend outside of major ticks range if necessary ----
if(!extend) {
tick.seq <- q
} else {
possible.low.minors <- min(at.maj) - ((n-1):1) * distance.between.minor
possible.hi.minors <- max(at.maj) + (1:(n-1)) * distance.between.minor
r3 <- possible.low.minors - min(usr)
r4 <- possible.hi.minors - max(usr)
p3 <- which.min(abs(r3))
p4 <- which.min(abs(r4))
if(!(abs(r3[p3]/min(usr)) < 1.5e-8) & r3[p3] < 0) p3 <- p3 + 1
if(!(abs(r4[p4]/max(usr)) < 1.5e-8) & r4[p4] > 0) p4 <- p4 - 1
if(p3 < length(possible.low.minors) + 1){
low.candidates <- seq(p3, length(possible.low.minors), 1)
low.laureates <- possible.low.minors[low.candidates]
} else {
low.laureates <- NULL
}
if(p4 > 0){
hi.candidates <- seq(1, p4, 1)
hi.laureates <- possible.hi.minors[ hi.candidates]
} else {
hi.laureates <- NULL
}
tick.seq <- c(low.laureates,q,hi.laureates)
}
res <- list(at.maj, tick.seq)
}
return(res)
}
Any scripts or data that you put into this service are public.
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.