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import scala.reflect.{ClassTag, classTag}
// ticket #421
object Test extends App {
def transpose[A: ClassTag](xss: Array[Array[A]]) = {
for (i <- Array.range(0, xss(0).length)) yield
for (xs <- xss) yield xs(i)
}
def scalprod(xs: Array[Double], ys: Array[Double]) = {
var acc = 0.0
for ((x, y) <- xs zip ys) acc = acc + x * y
acc
}
def matmul(xss: Array[Array[Double]], yss: Array[Array[Double]]) = {
val ysst = transpose(yss)
val ysst1: Array[Array[Double]] = yss.transpose
assert(ysst.deep == ysst1.deep)
for (xs <- xss) yield
for (yst <- ysst) yield
scalprod(xs, yst)
}
val a1 = Array(Array(0, 2, 4), Array(1, 3, 5))
println(transpose(a1).deep.mkString("[", ",", "]"))
println(matmul(Array(Array(2, 3)), Array(Array(5), Array(7))).deep.mkString("[", ",", "]"))
println(matmul(Array(Array(4)), Array(Array(6, 8))).deep.mkString("[", ",", "]"))
}
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