%useLatestDescriptors
%use lets-plot
//%use krangl

LetsPlot.getInfo()

%use krangl

val mpg_df = DataFrame.readCSV("https://raw.githubusercontent.com/JetBrains/lets-plot-kotlin/master/docs/examples/data/mpg.csv")
mpg_df.head()


val mpg = mpg_df.toMap()

// Default legend
val p = letsPlot(mpg) {x="displ"; y="hwy"; color="manufacturer"} + geomPoint(size=5.0) + ggsize(600,250)
p

// Layout the legend in two columns
p + scaleColorDiscrete(guide=guideLegend(ncol=2)) + ggtitle("Two columns legend")

// Same and fill by rows
p + scaleColorDiscrete(guide=guideLegend(ncol=2, byRow=true)) +
ggtitle("Two columns legend filled by rows")

// Adjust legend and axis
//  - five rows legend
//  - draw legend below plot
//  - remove axis
p + scaleColorDiscrete(guide=guideLegend(nrow=5)) +
    theme(axisTitle="blank").legendPositionBottom() +
    ggtitle("Five rows legend and below") + ggsize(700,400)

// Set color to city MPG and shape to drive·train
val p1 = letsPlot(mpg) {x="displ"; y="hwy"} + geomPoint(size=5.0) {color="cty"; shape="drv"} + ggsize(700, 350)
p1

// Change legend position and orientation
p1 + theme().legendPosition(1, 1).legendJustification(1, 1).legendDirectionHorizontal()

// Adjust colorbar size
// Change order in drive-train legend
// Set labels to legends and axis
// Remove vertical axis line
p1 + theme().legendPosition(1, 1).legendJustification(1, 1).legendDirectionHorizontal().axisLineYBlank() +
    scaleColorContinuous(name="City MPG", 
                         low="dark_blue", high="light_blue", 
                         guide=guideColorbar(barHeight=10, barWidth=300)) +
    scaleShape(name="Drive-train", breaks=listOf('f', 'r', '4'), labels=listOf("front", "rear", "4X4")) +
    xlab("Engine displacement (L)") + ylab("Highway MPG")