#' [.] Convert expressions in \code{ggplot2} object labels to strings
#'
#' Convert expressions in \code{\link[ggplot2]{ggplot}} object labels to strings, to
#' enable them to be plotted with \code{\link[plotly]{ggplotly}}.
#' @param p ggplot2 object
#'
#' @return `ggplot2` object
#' @export
#'
#' @examples
#'
#' \donttest{
#' \dontrun{
#' data(flu, package = "hyperSpec")
#'
#' qplotspc(flu)
#' ggplotly()
#'
#' rmExpr()
#' ggplotly()
#'
#' #--------------------------------
#' p1 <- qplot_sp(Loadings2)
#' p1$labels
#'
#' p2 <- rmExpr(p1)
#' p2$labels
#'
#' ggplotly(p1)
#' ggplotly(p2)
#'
#' #----------------------------------
#' qplotspc(aggregate(chondro, chondro$clusters, mean_pm_sd),
#' mapping = aes(x = .wavelength,
#' y = spc,
#' colour = clusters)) +
#' facet_grid(clusters ~ .) + ggtitle("Spectra of Chondrocytes")
#'
#' rmExpr()
#' ggplotly()
#'
#' }}
#'
#' @family \pkg{spHelper} plots
#' @family \pkg{spHelper} utilities
#' @author Vilmantas Gegzna
rmExpr <- function(p = ggplot2::last_plot()) {
p$labels <- lapply(p$labels, expr2text)
return(p)
}
#' [.] Unwrap text from `call` object
#' Assumption: only the second element in a `call` can be text
#' first element is an object of class "name", that can be dropped.
#' This algorithm can loose some text elements.
#'
#' @param x A `call` object
#'
#' @return A string.
#' @export
#' @family \pkg{spHelper} utilities
#' @author Vilmantas Gegzna
uncall <- function(x){
x <- as.list(x)[-1]
unwrapCall <- function(y) {
while (is.call(y)) {y <- as.list(y)[[2]]};
y
}
x <- lapply(x, unwrapCall)
paste(unlist(x),collapse = ", ")
}
#' [.] Convert `expression` and `call` to text and remove quotes
#'
#' @param x `Call` object or `expression`
#'
#' @export
#' @family \pkg{spHelper} utilities
#' @author Vilmantas Gegzna
#'
expr2text <- function(x) {
x <- switch(class(x),
# expression = simsalapar::escapeLatex(as.call(x)),
expression = {tryCatch(to_math_q(x),
error = function(e) as.character(x))},
call = uncall(x),
paste(as.character(x),collapse = " "))
x <- gsub('(^\")|(\"$)',"", x)
x <- gsub('\"',", ", x)
return(x)
}
# =============================================================================
#
# A partial implementation of a R expression -> latex math cnverter
#
# A partial implementation of a R expression -> latex math cnverter
#
# @param x A supported R plotmath expression.
#
# @return A LaTeX expression
# @author Hadley Wickham
#
# @source \href{https://gist.github.com/hadley/5576263}{latx-math.r}
#
# @examples
#
#
# to_math(x_1 + 1^{2 + 4} + 5 + sqrt(y) / 5 %/% 10)
# to_math(paste(x^2, y - 1, z_i))
# to_math(hat(tilde(ring(x))))
#
# to_math_q(expression(x+1))
#
#
# # ERROR (known bug):
#
# \donttest{
# \dontrun{
# to_math_q(expression(x+1))
# to_math(+1)
# to_math(x*+1)
# to_math(x^-a)
#
# }}
# @export
to_math <- function(x) {
to_math_q(substitute(x))
}
# @rdname to_math
# @export
to_math_q <- function(x) {
if (is.integer(x) || is.numeric(x)) return(x)
if (is.name(x)) {
x2 <- as.character(x)
x3 <- if (x2 %in% names(symbols)) symbols[[x2]] else x2
return(x3)
}
eval(x, lenv)
}
lenv <- new.env(parent = emptyenv())
dots <- function(...) {
eval(substitute(alist(...)))
}
# Convert a function into a fexpr: the function recieves only
# unevaluated args
fexpr <- function(f) {
stopifnot(is.function(f))
function(...) {
args <- dots(...)
do.call(f, args, quote = TRUE)
}
}
# Helper functions
unary_op <- function(left, right) {
fexpr(function(e1, e2) {
paste0(left, to_math_q(e1), right)
})
}
binary_op <- function(sep) {
fexpr(function(e1, e2) {
paste0(to_math_q(e1), " ", sep, " ", to_math_q(e2))
})
}
# Binary operators
lenv$"+" <- binary_op("+")
lenv$"-" <- binary_op("-")
lenv$"*" <- binary_op("*")
lenv$"/" <- binary_op("/")
lenv$"%+-%" <- binary_op("\\pm")
lenv$"%/%" <- binary_op("\\")
lenv$"%*%" <- binary_op("\\times")
lenv$"%.%" <- binary_op("\\cdot")
lenv$"[" <- binary_op("_")
lenv$"^" <- binary_op("^")
# Grouping
lenv$"{" <- unary_op("{", "}")
lenv$"(" <- unary_op("(", ")")
lenv$paste <- fexpr(function(...) {
paste0(unlist(lapply(list(...), to_math_q)), collapse = " ")
})
# Other math functions
lenv$sqrt <- unary_op("\\sqrt{", "}")
lenv$log <- unary_op("\\log{", "}")
lenv$inf <- unary_op("\\inf{", "}")
lenv$sup <- unary_op("\\sup{", "}")
lenv$frac <- fexpr(function(a, b) {
paste0("\\frac{", to_math_q(a), "}{", to_math_q(b), "}")
})
# Labelling
lenv$hat <- unary_op("\\hat{", "}")
lenv$tilde <- unary_op("\\tilde{", "}")
lenv$dot <- unary_op("\\dot{", "}")
lenv$ring <- unary_op("\\ring{", "}")
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.