adding an example app with a drell yatest file

build.sbt

@@ -4,7 +4,7 @@ organization := "org.diana-hep"
 
 licenses += ("Apache-2.0", url("http://www.apache.org/licenses/LICENSE-2.0"))
 
-version := "0.1.1"
+version := "0.1.3"
 //isSnapshot := true
 
 scalaVersion := "2.11.8"

src/main/scala/org/dianahep/sparkroot/apps/HiggsExampleApp.scala

@@ -0,0 +1,56 @@
+package org.dianahep.sparkroot.apps
+
+import org.apache.spark.sql.SparkSession
+import org.apache.spark.SparkContext
+import org.apache.spark.SparkContext._
+import org.apache.spark.SparkConf
+
+//import org.apache.spark.implicits._
+
+import org.dianahep.sparkroot._
+
+/**
+ * A simple example of reading a ROOT file into Spark's DataFrame.
+ * Define a case class to properly cast the Dataset[X]
+ * and print it out
+ *
+ * @author Viktor Khristenko
+ */
+
+object HiggsExampleApp {
+  case class Object();
+  case class Track(obj: Object, charge: Int, pt: Float, pterr: Float, eta: Float, phi: Float);
+  case class Electron(track: Track, ids: Seq[Boolean], trackIso: Float, ecalIso: Float, hcalIso: Float, dz: Double, isPF: Boolean, convVeto: Boolean);
+  case class Event(electrons: Seq[Electron]);
+
+  def main(args: Array[String]) {
+    if (args.size!=0) {
+      val inputFileName = args(0)
+      val conf = new SparkConf().setAppName("Higgs Example Application")
+      val spark = SparkSession.builder()
+        .master("local")
+        .appName("Higgs Example Application")
+        .getOrCreate()
+
+      doWork(spark, inputFileName)
+      spark.stop()
+    }
+    else {
+      println("No ROOT file provided")
+    }
+  }
+
+  def doWork(spark: SparkSession, inputName: String) = {
+    // load the ROOT file
+    val df = spark.sqlContext.read.root(inputName)
+
+    // see https://issues.apache.org/jira/browse/SPARK-13540
+    import spark.implicits._
+
+    // build the RDD out of the Dataset and filter out right away
+    val rdd = df.select("Electrons").as[Event].filter(_.electrons.size!=0).rdd
+
+    // print all the events where electrons are present
+    for (x <- rdd) println(x)
+  }
+}

src/main/scala/org/dianahep/sparkroot/core/TypeSystem.scala

@@ -705,7 +705,6 @@ case class SRVector(
         val size = buffer.readInt
 
         entry += 1L;
-        println(s"reading vector unsplitted $name")
         for (i <- 0 until size) yield t.read(buffer)
       }
     }
@@ -750,7 +749,6 @@ case class SRVector(
           val data = (for (x <- composite.members)
             yield {
             //we own the buffer
-            println(s"reading Array for member ${x.name} of composite: ${composite.name}")
             x.readArray(buffer, size)
             // increment the entry
           }).transpose.map(Row.fromSeq(_))