%useLatestDescriptors
%use lets-plot
%use krangl

var economics = DataFrame.readCSV("https://vincentarelbundock.github.io/Rdatasets/csv/ggplot2/economics.csv")

import java.text.SimpleDateFormat
val yyyyMmDd = SimpleDateFormat("yyyy-MM-dd")
economics = economics.addColumn("date") { it["date"].map<String> {yyyyMmDd.parse(it)}}
economics.head(3)

import java.util.Date
val startDate = yyyyMmDd.parse("2000-01-01")
economics = economics.filterByRow { (it["date"] as Date).compareTo(startDate) >= 0 }

letsPlot(economics.toMap()){x="date"; y="uempmed"} + 
 geomLine() + 
 scale_x_datetime() + 
 ggsize(900, 400)

letsPlot(economics.toMap()){x="date"; y="uempmed"} + 
 geomLine() + 
 scaleXDateTime(format="%b %Y") + 
 scaleYContinuous(format="{} %") + 
 ylab("unemployment rate") +
 ggsize(900, 400)

letsPlot(economics.toMap()){x="date"; y="uempmed"} + 
 geomLine(tooltips=layerTooltips()
        .line("Unemployment rate:|^y")
        .color("black")
        .anchor("top_center")
        .minWidth(170)) + 
 scaleXDateTime(format="%b %Y") + 
 scaleYContinuous(format="{} %") + 
 ylab("unemployment rate") +
 ggsize(900, 400)

val unemploymentMean = economics["uempmed"].mean()


letsPlot(economics.toMap()){x="date"; y="uempmed"} + 
 geomLine(tooltips=layerTooltips()
        .line("Unemployment rate:|^y")
        .color("black")
        .anchor("top_center")
        .minWidth(170)) + 
 geomHLine(yintercept=unemploymentMean, color="red", linetype="dashed", tooltips=tooltipsNone) +
 geomText(label=unemploymentMean.toString(), 
           labelFormat="{.2f} %",
           x=startDate.toInstant().toEpochMilli(), y=unemploymentMean!! + 0.5, 
           color="red") +
 scaleXDateTime(format="%b %Y") + 
 scaleYContinuous(format="{} %") + 
 ylab("unemployment rate") +
 ggtitle("The US Unemployment Rates 2000-2016.") +
 ggsize(900, 400)