GraphX要求你提供一个VertexId，这是每个顶点的唯一Long标识符。只使用RDD API，这需要一点技巧，但这里有一种方法可以做到这一点。
我没有你的csv文件的确切结构，这是我使用的：

> cat matrix.csv 
,A,B,C,D
A,0,3,2,5
B,-1,0,2,9
C,-1,-1,0,8
D,-1,-1,-1,0

在下面的内容中，我强调了您应该调整的代码行，您的文件可能会略有不同。

val data: RDD[(VertexId, String)] = sc.textFile("matrix.csv")
// getting the list of vertex names based on the CSV header
// adapt this line to your file structure
val vertex_names = data.first.split(",").tail

val vertices : RDD[ = data
    // removing the header, adapt this line to your file structure
    .filter(! _.startsWith(","))
    .zipWithIndex
    .map{ case (arr, id) => id -> arr.split(",")(0) }.cache()

val vert_index: RDD[(String, VertexId)] = vertices.map(_.swap)

// and now the gymnastic, we create a RDD of edges and then join with vert_index
// to replace vertex names by their VertexId 
val edges: RDD[Edge[Double]] = data
    .filter(! _.startsWith(","))
    .map(_.split(","))
    .map(arr => arr.head -> arr.tail.map(_.toDouble))
    .map{ case (letter, weights) => letter -> header.zip(weights) }
    .flatMapValues(x=>x) // this line generates one row per edge
    .join(vert_index).map{ case (_, ((out, weight), in)) => out -> (weight, in) }
    .join(vert_index).map{ case (_, ((weight, in), out)) => Edge(in, out, weight) }