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import java.util.Random
import Vector._
object LocalFileLR {
val D = 10 // Numer of dimensions
val rand = new Random(42)
case class DataPoint(x: Vector, y: Double)
def parsePoint(line: String): DataPoint = {
val nums = line.split(' ').map(_.toDouble)
return DataPoint(new Vector(nums.slice(1, D+1)), nums(0))
}
def main(args: Array[String]) {
val lines = scala.io.Source.fromPath(args(0)).getLines()
val points = lines.map(parsePoint _)
val ITERATIONS = args(1).toInt
// Initialize w to a random value
var w = Vector(D, _ => 2 * rand.nextDouble - 1)
println("Initial w: " + w)
for (i <- 1 to ITERATIONS) {
println("On iteration " + i)
var gradient = Vector.zeros(D)
for (p <- points) {
val scale = (1 / (1 + Math.exp(-p.y * (w dot p.x))) - 1) * p.y
gradient += scale * p.x
}
w -= gradient
}
println("Final w: " + w)
}
}
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