如何在Scala中将序列变量转换为矩阵

Question

This should be easy, but I'm stuck. I'm trying to convert a Seq[Seq[Double]] type into a Breeze DenseMatrix . (all nested Seq[Double]'s have the same number of elements.)

Converting a single sequence to a DenseVector is pretty easy:

val sss=Seq(2.3,3.4,2.0,1.0)
val bbb=DenseVector(sss:_*)

Is there any similar approach to convert a Seq[Seq[Double]] type to a DenseMatrix ? For example:

val sss=Seq(2.3,3.4,2.0,1.0)
val sssM=Seq(sss,sss,sss)
val bbb=DenseVector(sss:_*)
//val bbm= DenseMatrix(sssM:_*:??)  //????

Answer 1

I noticed that the same approach works fine:

val sss=Seq(2.3,3.4,2.0,1.0)
val sssM=Seq(sss,sss,sss)
val bbb=DenseVector(sss:_*)
val bbm= DenseMatrix(sssM:_*)

Initially I had thought that we need to expand each nested sequence as well. But as stated by Rex Kerr, in a comment below, the Breeze library automatically takes care of that.