Some fixes to the examples (mostly to use functional API)

This commit is contained in:
Matei Zaharia 2012-01-31 00:33:18 -08:00
parent fabcc82528
commit 100e800782
4 changed files with 72 additions and 76 deletions

View file

@ -40,12 +40,10 @@ object SparkHdfsLR {
for (i <- 1 to ITERATIONS) {
println("On iteration " + i)
val gradient = sc.accumulator(Vector.zeros(D))
for (p <- points) {
val scale = (1 / (1 + exp(-p.y * (w dot p.x))) - 1) * p.y
gradient += scale * p.x
}
w -= gradient.value
val gradient = points.map { p =>
(1 / (1 + exp(-p.y * (w dot p.x))) - 1) * p.y * p.x
}.reduce(_ + _)
w -= gradient
}
println("Final w: " + w)

View file

@ -8,66 +8,66 @@ import scala.collection.mutable.HashMap
import scala.collection.mutable.HashSet
object SparkKMeans {
val R = 1000 // Scaling factor
val rand = new Random(42)
def parseVector(line: String): Vector = {
return new Vector(line.split(' ').map(_.toDouble))
}
def closestPoint(p: Vector, centers: HashMap[Int, Vector]): Int = {
var index = 0
var bestIndex = 0
var closest = Double.PositiveInfinity
for (i <- 1 to centers.size) {
val vCurr = centers.get(i).get
val tempDist = p.squaredDist(vCurr)
if (tempDist < closest) {
closest = tempDist
bestIndex = i
}
}
return bestIndex
}
val R = 1000 // Scaling factor
val rand = new Random(42)
def parseVector(line: String): Vector = {
return new Vector(line.split(' ').map(_.toDouble))
}
def closestPoint(p: Vector, centers: HashMap[Int, Vector]): Int = {
var index = 0
var bestIndex = 0
var closest = Double.PositiveInfinity
for (i <- 1 to centers.size) {
val vCurr = centers.get(i).get
val tempDist = p.squaredDist(vCurr)
if (tempDist < closest) {
closest = tempDist
bestIndex = i
}
}
return bestIndex
}
def main(args: Array[String]) {
if (args.length < 4) {
System.err.println("Usage: SparkLocalKMeans <master> <file> <k> <convergeDist>")
System.exit(1)
}
val sc = new SparkContext(args(0), "SparkLocalKMeans")
val lines = sc.textFile(args(1))
val data = lines.map(parseVector _).cache()
val K = args(2).toInt
val convergeDist = args(3).toDouble
var points = data.takeSample(false, K, 42)
var kPoints = new HashMap[Int, Vector]
var tempDist = 1.0
for (i <- 1 to points.size) {
kPoints.put(i, points(i-1))
}
def main(args: Array[String]) {
if (args.length < 4) {
System.err.println("Usage: SparkLocalKMeans <master> <file> <k> <convergeDist>")
System.exit(1)
}
val sc = new SparkContext(args(0), "SparkLocalKMeans")
val lines = sc.textFile(args(1))
val data = lines.map(parseVector _).cache()
val K = args(2).toInt
val convergeDist = args(3).toDouble
var points = data.takeSample(false, K, 42)
var kPoints = new HashMap[Int, Vector]
var tempDist = 1.0
for (i <- 1 to points.size) {
kPoints.put(i, points(i-1))
}
while(tempDist > convergeDist) {
var closest = data.map (p => (closestPoint(p, kPoints), (p, 1)))
var pointStats = closest.reduceByKey {case ((x1, y1), (x2, y2)) => (x1 + x2, y1+y2)}
var newPoints = pointStats.map {mapping => (mapping._1, mapping._2._1/mapping._2._2)}.collect()
tempDist = 0.0
for (mapping <- newPoints) {
tempDist += kPoints.get(mapping._1).get.squaredDist(mapping._2)
}
for (newP <- newPoints) {
kPoints.put(newP._1, newP._2)
}
}
while(tempDist > convergeDist) {
var closest = data.map (p => (closestPoint(p, kPoints), (p, 1)))
var pointStats = closest.reduceByKey {case ((x1, y1), (x2, y2)) => (x1 + x2, y1+y2)}
var newPoints = pointStats.map {pair => (pair._1, pair._2._1 / pair._2._2)}.collect()
tempDist = 0.0
for (pair <- newPoints) {
tempDist += kPoints.get(pair._1).get.squaredDist(pair._2)
}
for (newP <- newPoints) {
kPoints.put(newP._1, newP._2)
}
}
println("Final centers: " + kPoints)
}
println("Final centers: " + kPoints)
}
}

View file

@ -38,12 +38,10 @@ object SparkLR {
for (i <- 1 to ITERATIONS) {
println("On iteration " + i)
val gradient = sc.accumulator(Vector.zeros(D))
for (p <- sc.parallelize(data, numSlices)) {
val scale = (1 / (1 + exp(-p.y * (w dot p.x))) - 1) * p.y
gradient += scale * p.x
}
w -= gradient.value
val gradient = sc.parallelize(data, numSlices).map { p =>
(1 / (1 + exp(-p.y * (w dot p.x))) - 1) * p.y * p.x
}.reduce(_ + _)
w -= gradient
}
println("Final w: " + w)

View file

@ -12,12 +12,12 @@ object SparkPi {
}
val spark = new SparkContext(args(0), "SparkPi")
val slices = if (args.length > 1) args(1).toInt else 2
var count = spark.accumulator(0)
for (i <- spark.parallelize(1 to 100000, slices)) {
val n = 100000 * slices
val count = spark.parallelize(1 to n, slices).map { i =>
val x = random * 2 - 1
val y = random * 2 - 1
if (x*x + y*y < 1) count += 1
}
println("Pi is roughly " + 4 * count.value / 100000.0)
if (x*x + y*y < 1) 1 else 0
}.reduce(_ + _)
println("Pi is roughly " + 4.0 * count / n)
}
}