#' Create an HTML radar charts widget using the ECharts(version:3.2.2) library

#'

#' This function creates an HTML widget to display data.frame using the JavaScript library ECharts3.

#' @param dat a data object (a data frame or a factor array)

#' @param xvar,yvar objects of class "formula" (or one that can be coerced

#' to that class): x,y coordinates of the given data.frame colnames, e.g.

#' \code{xvar = ~xAxisName}; \code{yvar = ~yAxisName}. xvar, yvar are needed for the

#' data.frame data input.

#' @param series an "formula" object: Associates the levels of variable

#' with symbol color, e.g. \code{series = ~groupName}

#' @param size an array of html widget width and height(either numeric pixels

#' or percentage could be accepted): e.g. size = c(1024, 768).

#' @param ymin,ymax a numeric array with the same length of unique(xvar), to set the

#' limitation for each polar axis limitation. if you want to set someone to be default

#' limitation, you can set the given array index to NULL, examples input:

#' \code{ymin = c(NULL, 1000, 2000, 3000)}

#' @param theme an object of theme name. see(\url{http://datatables.net/extensions/index}) for detail.

#' supported theme: \code{c("default", "vintage", "dark", "westeros", "essos", "wonderland", "walden",

#' "chalk", "infographic", "macarons", "roma", "shine", "purple-passion")}

#' @param title an overall title for the plot. you can modify title widget after chart has been

#' generated: Echart + eTitle(title = "your title.")

#' @param title.x,title.y the xy coordinates of main title, besides the excat exact pixels value,

#' x accept c("left", "right", "center") and y accept c("top", "bottom", "center") as legal input.

#' you can modify title widget after chart has been generated:

#' \code{Echart + eTitle(title="main title", x = "left", y=10)}

#' @param legend logical whether the legend widget show or not, default is TRUE.

#' you can modify legend widget after chart has been generated, the legend position and

#' legend orientation are available at present.

#' \code{Echart + eLegend(show = TRUE)}

#' @param legend.x,legend.y the xy coordinates of legend, besides the excat exact pixels value,

#' x accept c("left", "right", "center") and y accept c("top", "bottom", "center") as legal input.

#' you can modify legend widget after chart has been generated:

#' \code{Echart + eLegend(x = "right", y="top")}

#' @param legend.orient an element of c("horizontal", "vertical"), default is "horizontal"

#' you can modify legend widget after chart has been generated:

#' \code{Echart + eLegend(orient = "vertical")}

#' @param toolbox logical whether the toolbox widget show or not, default is TRUE.

#' you can modify toolbox widget after chart has been generated, the toolbox position, toolbox

#' element and toolbox orientation are available at present.

#' \code{Echart + eToolbox(show = TRUE)}

#' @param toolbox.x,toolbox.y the xy coordinates of toolbox, besides the excat exact pixels value,

#' x accept c("left", "right", "center") and y accept c("top", "bottom", "center") as legal input.

#' you can modify toolbox widget after chart has been generated:

#' \code{Echart + eToolbox(x = "right", y="top")}

#' @param toolbox.orient an element of c("horizontal", "vertical"), default is "horizontal"

#' you can modify toolbox widget after chart has been generated:

#' \code{Echart + eToolbox(orient = "vertical")}

#' @param dataview,mark,restore,dataZoom,magicType logical variable whether the dataview

#' , mark, restore, dataZoom or magicType tool in toolbox widget show or not,

#' default is TRUE. you can modify toolbox widget after chart has been generated,

#' the toolbox position, toolbox element and toolbox orientation are available at present.

#' \code{Echart + eToolbox(dataView = FALSE)}

#' @param tooltip logical whether the tooltip widget for front-end interactive chart

#' show or not. default is TRUE. you can modify tooltip widget after chart has been generated,

#' the tooltip trigger and tooltip formatter is available at present.

#' \code{Echart + eTooltip(show = FALSE)}

#' @param tooltip.trigger an element of c("axis", "item"), default is "axis" for radar chart.

#' "axis" option for trigger will show all the information of mouse;

#' "item" option for tirgger will only show the given item information of mouse.

#' you can modify tooltip widget after chart has been generated:

#' \code{Echart + eTooltip(trigger = "axis")}

#' @param tooltip.formatter the information formatter for tooltip widget,

#' default is "<a>:<b><c>" for radar chart.

#' you can modify tooltip widget after chart has been generated:

#' \code{Echart + eTooltip(formatter = "<a><b>:<c>")}

#' @param calculable logical whether the front-end interactive chart will

#' support the drag-recalculable feature.

#' the size and calculable option can be setted after radar chart has been

#' generated through eOption: \code{Echart + eOption(calculable = TRUE)}

#' @param showLabel logical whether the region name label showed on chart.

#' default is TRUE, e.g. \code{Echart + eOption(showLabel = TRUE)}

#' @note You are recommended to use lazyPlot function for interactive chart

#' option set through "shiny" server.

#' @export

#' @examples

#' require(plyr)

#' dat = ddply(iris, .(Species), colwise(mean))

#' rownames(dat) = dat[,1]

#' dat = dat[, -1]

#' dat

#' eRadar(dat)

#' df2 <- data.frame(

#' saleNum=c(10,20,30,40,50,60,70,15,25,35,45,55,65,75,25,35,45,55,65,75,85),

#' seller=c(rep("Yellow",7), rep("Red",7), rep("White",7)),

#' weekDay = c(rep(c("Mon","Tue","Wed","Thu","Fri","Sat","Sun"),3))

#' )

#' dat <- df2

#' xvar=~weekDay; yvar= ~saleNum; series=~seller

#' eRadar(df2, ~weekDay, ~saleNum, ~seller)

eRadar = function(dat, xvar=NULL, yvar=NULL, series=NULL, size = NULL, ymin=vector(), ymax=vector(),

theme = "default", title = NULL, subtitle = NULL, title.x = "center", title.y = "top",

legend = TRUE, legend.data=NULL, legend.x = "left", legend.y= "top", legend.orient="horizontal",

toolbox = TRUE, toolbox.orient = "horizontal", toolbox.x = "right", toolbox.y = "top",

dataView = TRUE, readOnly = FALSE, mark=TRUE, dataZoom=FALSE, magicType=FALSE,

tooltip = TRUE, tooltip.trigger="item", formatter="", axis.scale=TRUE,

xlab=FALSE, ylab=FALSE, calculable=TRUE, showLabel=TRUE, opt = list())

{

xlabName = autoArgLabel(xvar, deparse(substitute(xvar)))

ylabName = autoArgLabel(yvar, deparse(substitute(yvar)))

xvar = as.factor(evalFormula(xvar, dat))

yvar = evalFormula(yvar, dat)

series = as.factor(evalFormula(series, dat))

# data flow format..

# if series is null, we will use the xvar and yvar to construct the bar plot..

if(is.null(xvar) & is.null(yvar) & !is.factor(dat)){

# Mode 1. use default data.frame as input...

dat <- as.data.frame(dat, stringsAsFactor=F)

}else if(!is.null(xvar) & !is.null(yvar) & !is.null(series)){

#print("Mode1")

# Mode 2. all of xvar, yvar and series are valid...

dat <- with(dat, {

out <- matrix(nrow=nlevels(series), ncol=nlevels(xvar),

dimnames=list(levels(series), levels(xvar)))

out[cbind(series, xvar)] <- yvar

out

})

dat <- as.data.frame(dat)

}else if(!is.null(xvar) & !is.null(yvar) & is.null(series)){

# Mode 3. format dat with only x and y variable.

dat <- data.frame(val = yvar)

colnames(dat) <- ylabName

rownames(dat) <- xvar

}else if(is.null(xvar) & is.null(yvar) & is.factor(dat)){

# Mode 4. factor

tempD <- as.data.frame(table(dat))

dat <- data.frame(val = tempD[,"Freq"])

colnames(dat) <- "Frequency"

rownames(dat) <- tempD[,1]

}

# option$title format.

opt$title = tilteSet(title = title, subtitle=subtitle,

title.x = title.x, title.y = title.y)

opt$calculable = calculableSet(calculable = calculable)

opt$theme = themeSet(theme = theme)

# opt$tooltip format, not open to user now.

opt$tooltip = tooltipSet( tooltip=tooltip,trigger=tooltip.trigger,

formatter = "", islandFormatter="")

opt$toolbox = toolboxSet(toolbox=toolbox, toolbox.x=toolbox.x, toolbox.y=toolbox.y, orient=toolbox.orient,

dataView=dataView, mark=mark, dataZoom = dataZoom, magicType = magicType, restore = TRUE, readOnly = readOnly,

saveAsImage=TRUE)

if(missing(legend.data) | is.null(legend.data)){legendData = rownames(dat)

}else{legendData = legend.data}

opt$legend = legendSet( show=legend, data=legendData, legend.x=legend.x, legend.y=legend.y, orient=legend.orient)

opt$polar = list(polarSet(name=colnames(dat), ymin=ymin, ymax=ymax))

datList = vector("list", nrow(dat))

for(i in 1:nrow(dat)){

datList[[i]]$name = rownames(dat)[i]

datList[[i]]$value = unnames(unlist(dat[i,]))

}

names(datList) = NULL

if(is.null(opt$series)) {

opt$series = vector("list", 1)

}

if(is.null(opt$series[[1]]$type)) {

opt$series[[1]]$type = 'radar'

}

if(is.null(opt$series[[1]]$data)) {

opt$series[[1]]$data = datList

}

opt$size = size

### output list format

chart = htmlwidgets::createWidget(

'echarts', opt,

package = 'recharts', width = size[1], height = size[2],

preRenderHook = function(instance) {

instance

}

)

chart = .addClass(chart, "eRadar")

# add theme dependencies

chart = addThemeDependencies(chart)

chart

}