josep2

import spray.json._

val myJson: String = "{
		color: "red",
		value: "#f00"
	}" // JSON defined above 

case class Settings(color: String, value: String) // Case class for the JSON

object SettingsProtocol extends DefaultJsonProtocol {

josep2

[
	{
		color: "red",
		value: "#f00"
	},
	{
		color: "green",
		value: "#0f0"
	},
	{

josep2

val harmonic = new HarmonicMean

data.agg(harmonic(col("sales")).as("HarmonicMean")).show()


+-----------------+
|    GeometricMean|
+-----------------+
|473.3701657458564|
+-----------------+

josep2

for( var x <- Range ){
   statement(s);
}

josep2

// Taken From: https://github.com/apache/spark/blob/master/sql/core/src/main/scala/org/apache/spark/sql/expressions/udaf.scala#L128-L136

  @scala.annotation.varargs
  def apply(exprs: Column*): Column = {
    val aggregateExpression =
      AggregateExpression(
        ScalaUDAF(exprs.map(_.expr), this),
        Complete,
        isDistinct = false)
    Column(aggregateExpression)

josep2

class ProductSum extends UserDefinedAggregateFunction {

  override def inputSchema: org.apache.spark.sql.types.StructType =
    StructType(Seq(StructField("value", DoubleType), StructField("value2", DoubleType)))

  override def bufferSchema: StructType = StructType(
    StructField("product", DoubleType) :: Nil
  )

  override def dataType: DataType = DoubleType

josep2

import org.apache.spark.sql.expressions.MutableAggregationBuffer
import org.apache.spark.sql.expressions.UserDefinedAggregateFunction
import org.apache.spark.sql.Row
import org.apache.spark.sql.types._

class HarmonicMean extends UserDefinedAggregateFunction {
  
  // Defind the schema of the input data
  override def inputSchema: org.apache.spark.sql.types.StructType =
    StructType(StructField("value", DoubleType) :: Nil)

josep2

class GeometricMean extends UserDefinedAggregateFunction ...

josep2

  def harmonicMean(values: Seq[Double]): Double = {
    values.length / values.map(v => 1.0 / v).sum
  }
  
  // Borrowed from: https://github.com/Leksyk/ml/blob/3d2c8ede6ff99d8c6ec3f830e6a4c49b85ee8e82/similar-words/src/main/scala/Utils.scala

josep2

  def harmonicMean(values: Seq[Double]): Double = {
    values.length / values.map(v => 1.0 / v).sum
  }