我正在尝试在 R 中创建一个交互式直方图,可以通过移动滑块或在文本框中输入一个值来调整其 bin 宽度。除此之外,我还想为用户提供一个选项,可以为特定的 bin 宽度保存绘图。
为此,我发现 'aplpack' 库的 'gslider' 函数是一个很好的起点。我试图修改它以满足我的目的,并了解更多关于 Tcl/Tk 结构的信息。但是我现在卡住了,无法继续,主要是因为我还没有完全理解如何捕获滑块值并在函数之间传输。
以下是我还没有真正理解的代码片段。这些来自“gslider”函数的源代码。
# What is the rationale behind using the 'assign' function here and at
# other instances in the code?
img <- tkrplot::tkrplot(gr.frame, newpl, vscale = 1, hscale = 1)
tkpack(img, side = "top")
assign("img", img, envir = slider.env)
# I understand the below lines when considered individually. But collectively,
# I am having a difficult time comprehending them. Most importantly, where
# exactly is the slider movement captured here?
sc <- tkscale(fr, from = sl.min, to = sl.max,
showvalue = TRUE, resolution = sl.delta, orient = "horiz")
assign("sc", sc, envir = slider.env)
eval(parse(text = "tkconfigure(sc, variable=inputbw1)"), envir = slider.env)
sl.fun <- sl.function
if (!is.function(sl.fun))
sl.fun <- eval(parse(text = paste("function(...){",
sl.fun, "}")))
fname <- 'tkrrsl.fun1'
eval(parse(text = c(paste(fname, " <-"), " function(...){",
"tkrreplot(get('img',envir=slider.env),fun=function()",
deparse(sl.fun)[-1], ")", "}")))
eval(parse(text = paste("environment(", fname, ")<-parent.env")))
if (prompt)
tkconfigure(sc, command = get(fname))
else tkbind(sc, "<ButtonRelease>", get(fname))
if (exists("tkrrsl.fun1")) {
get("tkrrsl.fun1")()
}
assign("slider.values.old", sl.default, envir = slider.env)
感谢大家提供不同范围的答案。Juba 和 Greg 的答案是我可以编写以下代码的答案:
slider_txtbox <- function (x, col=1, sl.delta, title)
{
## Validations
require(tkrplot)
pos.of.panel <- 'bottom'
if(is.numeric(col))
col <- names(x)[col]
x <- x[,col, drop=FALSE]
if (missing(x) || is.null(dim(x)))
return("Error: insufficient x values")
sl.min <- sl.delta # Smarter initialization required
sl.max <- max(x)
xrange <- (max(x)-min(x))
sl.default <- xrange/30
if (!exists("slider.env")) {
slider.env <<- new.env(parent = .GlobalEnv)
}
if (missing(title))
title <- "Adjust parameters"
## Creating initial dialogs
require(tcltk)
nt <- tktoplevel()
tkwm.title(nt, title)
if(.Platform$OS.type == 'windows')
tkwm.geometry(nt, "390x490+0+10")
else if(.Platform$OS.type == 'unix')
tkwm.geometry(nt, "480x600+0+10")
assign("tktop.slider", nt, envir = slider.env)
"relax"
nt.bak <- nt
sl.frame <- tkframe(nt)
gr.frame <- tkframe(nt)
tx.frame <- tkframe(nt)
tkpack(sl.frame, tx.frame, gr.frame, side = pos.of.panel)
## Function to create and refresh the plot
library(ggplot2)
library(gridExtra)
makeplot <- function(bwidth, save) {
if(bwidth <= 0) {
df <- data.frame('x'=1:10, 'y'=1:10)
histplot <- ggplot(df, aes(x=x, y=y)) + geom_point(size=0) + xlim(0, 10) + ylim(0, 100) +
geom_text(aes(label='Invalid binwidth...', x=5, y=50), size=9)
} else {
histplot <- ggplot(data=x, aes_string(x=col)) +
geom_histogram(binwidth=bwidth, aes(y = ..density..), fill='skyblue') +
theme(axis.title.x=element_text(size=15), axis.title.y=element_text(size=15),
axis.text.x=element_text(size=10, colour='black'),
axis.text.y=element_text(size=10, colour='black'))
}
print(histplot)
if(save){
filename <- tkgetSaveFile(initialfile=paste('hist_bw_', bwidth, sep=''),
filetypes='{{PNG files} {.png}} {{JPEG files} {.jpg .jpeg}}
{{PDF file} {.pdf}} {{Postscript file} {.ps}}')
filepath <- as.character(filename)
splitpath <- strsplit(filepath, '/')[[1]]
flname <- splitpath[length(splitpath)]
pieces <- strsplit(flname, "\\.")[[1]]
ext <- tolower(pieces[length(pieces)])
if(ext != 'png' && ext != 'jpeg' && ext != 'jpg' && ext != 'pdf' && ext != 'ps') {
ext <- 'png'
filepath <- paste(filepath, '.png', sep='')
filename <- tclVar(filepath)
}
if(ext == 'ps')
ext <- 'postscript'
eval(parse(text=paste(ext, '(file=filepath)', sep='')))
eval(parse(text='print(histplot)'))
dev.off()
}
}
img <- tkrplot::tkrplot(gr.frame, makeplot(sl.default, FALSE), vscale = 1, hscale = 1)
tkpack(img, side = "top")
assign("img", img, envir = slider.env)
## Creating slider, textbox and labels
parent.env <- sys.frame(sys.nframe() - 1)
tkpack(fr <- tkframe(sl.frame), side = 'top')
sc <- tkscale(fr, from = sl.min, to = sl.max,
showvalue = TRUE, resolution = sl.delta,
orient = "horiz")
tb <- tkentry(fr, width=4)
labspace <- tklabel(fr, text='\t\t\t')
tkpack(sc, labspace, tb, side = 'left')
tkpack(textinfo <- tkframe(tx.frame), side = 'top')
lab <- tklabel(textinfo, text = ' Move slider', width = "20")
orlabel <- tklabel(textinfo, text=' OR', width='10')
txtboxmsg <- tklabel(textinfo, text = 'Enter binwidth', width='20')
tkpack(txtboxmsg, orlabel, lab, side='right')
tkpack(f.but <- tkframe(sl.frame))
tkpack(tklabel(f.but, text=''))
tkpack(tkbutton(f.but, text = "Exit", command = function() tkdestroy(nt)),
side='right')
tkpack(tkbutton(f.but, text = "Save", command = function(...) {
bwidth <- as.numeric(tclvalue(get('inputtb', envir=slider.env)))
tkrreplot(get('img',envir=slider.env),fun=function() { makeplot(bwidth, TRUE); sync_slider()})
}), side='right')
## Creating objects and variables associated with slider and textbox
assign("sc", sc, envir = slider.env)
eval(parse(text = "assign('inputsc', tclVar(sl.default), envir=slider.env)"))
eval(parse(text = "tkconfigure(sc, variable=inputsc)"), envir = slider.env)
assign("tb", tb, envir = slider.env)
eval(parse(text = "assign('inputtb', as.character(tclVar(sl.default)),
envir=slider.env)"))
eval(parse(text = "tkconfigure(tb, textvariable=inputtb)"), envir = slider.env)
## Function to update the textbox value when the slider has changed
sync_textbox <- function() {
bwidth_sl <- tclvalue(get('inputsc', envir=slider.env))
assign('inputtb', tclVar(bwidth_sl), envir=slider.env)
eval(parse(text = "tkconfigure(tb, textvariable=inputtb)"), envir = slider.env)
}
## Function to update the slider value when the textbox has changed
sync_slider <- function() {
bwidth_tb <- tclvalue(get('inputtb', envir=slider.env))
assign('inputsc', tclVar(bwidth_tb), envir=slider.env)
eval(parse(text = "tkconfigure(sc, variable=inputsc)"), envir = slider.env)
}
## Bindings : association of certain functions to certain events for the slider
## and the textbox
tkbind(sc, "<ButtonRelease>", function(...) {
bwidth <- as.numeric(tclvalue(get('inputsc', envir=slider.env)))
tkrreplot(get('img',envir=slider.env),fun=function() { makeplot(bwidth, FALSE); sync_textbox()})
})
tkbind(tb, "<Return>", function(...) {
bwidth <- as.numeric(tclvalue(get('inputtb', envir=slider.env)))
if(bwidth > sl.max && !is.na(bwidth)) {
bwidth <- sl.max
assign('inputtb', tclVar(bwidth), envir=slider.env)
eval(parse(text = "tkconfigure(tb, textvariable=inputtb)"), envir = slider.env)
} else
if(bwidth < sl.min || is.na(bwidth)) {
bwidth <- sl.min
assign('inputtb', tclVar(bwidth), envir=slider.env)
eval(parse(text = "tkconfigure(tb, textvariable=inputtb)"), envir = slider.env)
}
tkrreplot(get('img',envir=slider.env),fun=function() { makeplot(bwidth, FALSE); sync_slider()})
})
}
library(ggplot2)
slider_txtbox(movies, 'rating', 0.1, 'Adjust binwidth')