Data commit

Task/Text-processing-1/Scala/text-processing-1-1.scala

@@ -0,0 +1,58 @@
+object DataMunging {
+  import scala.io.Source
+
+  def spans[A](list: List[A]) = list.tail.foldLeft(List((list.head, 1))) {
+    case ((a, n) :: tail, b) if a == b => (a, n + 1) :: tail
+    case (l, b) => (b, 1) :: l
+  }
+
+  type Flag = ((Boolean, Int), String)
+  type Flags = List[Flag]
+  type LineIterator = Iterator[Option[(Double, Int, Flags)]]
+
+  val pattern = """^(\d+-\d+-\d+)""" + """\s+(\d+\.\d+)\s+(-?\d+)""" * 24 + "$" r;
+
+  def linesIterator(file: java.io.File) = Source.fromFile(file).getLines().map(
+    pattern findFirstMatchIn _ map (
+      _.subgroups match {
+        case List(date, rawData @ _*) =>
+          val dataset = (rawData map (_ toDouble) iterator) grouped 2 toList;
+          val valid = dataset filter (_.last > 0) map (_.head)
+          val validSize = valid length;
+          val validSum = valid sum;
+          val flags = spans(dataset map (_.last > 0)) map ((_, date))
+          println("Line: %11s  Reject: %2d  Accept: %2d  Line_tot: %10.3f  Line_avg: %10.3f" format
+                  (date, 24 - validSize, validSize, validSum, validSum / validSize))
+          (validSum, validSize, flags)
+      }
+    )
+  )
+
+  def totalizeLines(fileIterator: LineIterator) =
+    fileIterator.foldLeft(0.0, 0, List[Flag]()) {
+      case ((totalSum, totalSize, ((flag, size), date) :: tail), Some((validSum, validSize, flags))) =>
+        val ((firstFlag, firstSize), _) = flags.last
+        if (firstFlag == flag) {
+          (totalSum + validSum, totalSize + validSize, flags.init ::: ((flag, size + firstSize), date) :: tail)
+        } else {
+          (totalSum + validSum, totalSize + validSize, flags ::: ((flag, size), date) :: tail)
+        }
+      case ((_, _, Nil), Some(partials)) => partials
+      case (totals, None) => totals
+    }
+
+  def main(args: Array[String]) {
+    val files = args map (new java.io.File(_)) filter (file => file.isFile && file.canRead)
+    val lines =  files.iterator flatMap linesIterator
+    val (totalSum, totalSize, flags) = totalizeLines(lines)
+    val ((_, invalidCount), startDate) = flags.filter(!_._1._1).max
+    val report = """|
+                    |File(s)  = %s
+                    |Total    = %10.3f
+                    |Readings = %6d
+                    |Average  = %10.3f
+                    |
+                    |Maximum run(s) of %d consecutive false readings began at %s""".stripMargin
+    println(report format (files mkString " ", totalSum, totalSize, totalSum / totalSize, invalidCount, startDate))
+  }
+}

Task/Text-processing-1/Scala/text-processing-1-2.scala

@@ -0,0 +1,42 @@
+object AltDataMunging {
+  def main(args: Array[String]) {
+    var totalSum = 0.0
+    var totalSize  = 0
+    var maxInvalidDate = ""
+    var maxInvalidCount = 0
+    var invalidDate = ""
+    var invalidCount = 0
+    val files = args map (new java.io.File(_)) filter (file => file.isFile && file.canRead)
+
+    files.iterator flatMap (file => Source fromFile file getLines ()) map (_.trim split "\\s+") foreach {
+      case Array(date, rawData @ _*) =>
+        val dataset = (rawData map (_ toDouble) iterator) grouped 2 toList;
+        val valid = dataset filter (_.last > 0) map (_.head)
+        val flags = spans(dataset map (_.last > 0)) map ((_, date))
+        println("Line: %11s  Reject: %2d  Accept: %2d  Line_tot: %10.3f  Line_avg: %10.3f" format
+                (date, 24 - valid.size, valid.size, valid.sum, valid.sum / valid.size))
+        totalSum += valid.sum
+        totalSize += valid.size
+        dataset foreach {
+          case _ :: flag :: Nil if flag > 0 =>
+            if (invalidCount > maxInvalidCount) {
+              maxInvalidDate = invalidDate
+              maxInvalidCount = invalidCount
+            }
+            invalidCount = 0
+          case _ =>
+            if (invalidCount == 0) invalidDate = date
+            invalidCount += 1
+        }
+    }
+
+    val report = """|
+                    |File(s)  = %s
+                    |Total    = %10.3f
+                    |Readings = %6d
+                    |Average  = %10.3f
+                    |
+                    |Maximum run(s) of %d consecutive false readings began at %s""".stripMargin
+    println(report format (files mkString " ", totalSum, totalSize, totalSum / totalSize, maxInvalidCount, maxInvalidDate))
+  }
+}