Details
Description
require(numCols == mat.numCols, "The number of rows of the matrices in this sequence, " + "don't match!")
Shall the error message be "The number of columns..."?
This issue also appears in the open source spark:
https://github.com/apache/spark/blob/master/mllib-local/src/main/scala/org/apache/spark/ml/linalg/Matrices.scala#L1266