[BlockMatrix] multiply is an action or a transformation ?
Hi Everyone, Sorry if the question can be simple, or confusing, but I have not see anywhere in documentation the anwser: Is multiply method in BlockMatrix a transformation or an action. I mean, in order that the multiplication is effectively done it is enough with calling : m1.multiply(m2), Or do I have to make something like m1.multiply(m2).count(). Thanks. -- -- Buen dia, alegria !! José Francisco Saray Villamizar cel +33 6 13710693 Lyon, France
Spark SVD benchmark for dense matrices
Hi everyone, I am trying to invert a 5000 x 5000 Dense Matrix (99% non-zeros), by using SVD with an approach simmilar to : https://stackoverflow.com/questions/29969521/how-to-compute-the-inverse-of-a-rowmatrix-in-apache-spark The time Im getting with SVD is close to 10 minutes what is very long for me. A benchmark for SVD is already given here https://databricks.com/blog/2014/07/21/distributing-the-singular-value-decomposition-with-spark.html However, it seems they are using sparse matrices, thats why they get short times. Have anyone of you try to perform a SVD on a very dense big matrix . ? Is this time normal ? Thank you. -- -- Buen dia, alegria !! José Francisco Saray Villamizar cel +33 6 13710693 Lyon, France
