%useLatestDescriptors
%use lets-plot
@file:DependsOn("com.github.doyaaaaaken:kotlin-csv-jvm:0.7.3")

import com.github.doyaaaaaken.kotlincsv.client.*

val csvData = java.io.File("mpg.csv")

val mpg: List<Map<String, String>> = CsvReader().readAllWithHeader(csvData)

fun col(name: String, discrete: Boolean=false): List<*> {
    return mpg.map {
        val v = it[name]
        if(discrete) v else v?.toDouble()
    }
}

val df = mapOf(
    "displ" to col("displ"),
    "hwy" to col("hwy"),
    "cyl" to col("cyl"),
    "index" to col(""),
    "cty" to col("cty"),
    "drv" to col("drv", true),
    "year" to col("year")
)

// Mapping
letsPlot(df) {x = "displ"; y = "hwy"; color = "cyl"} + geomPoint(df)

val p = letsPlot(df)
p + geomPoint(df, stat = Stat.count()) {x = "displ"; color = "..count.."; size = "..count.."}

val p = letsPlot(df) {x = "displ"; y = "hwy"; color = "cyl"}
p + 
    geomPoint(df, position = positionNudge()) + 
    scaleColorContinuous("red", "green", guide = guideLegend(ncol=2)) + 
    ggtitle("Displacement by horsepower")    

val p = letsPlot(df) {x = "displ"; y = "hwy"; color = "cyl"}
p   + geomPoint(
      data=df, position = positionNudge(), 
      sampling = samplingRandomStratified(40)
  ) + scaleColorContinuous(
      "blue", "pink",
      guide = guideLegend(ncol=2)
  )