According to the definition of uniformVectorRDD, it is supposed to generate the uniformly distributed data with mean ~0.0 and standard deviation ~1.
[Definition: Generates an RDD comprised of i.i.d. samples from the uniform distribution U(0.0, 1.0).]
But it is generating the data with mean ~0.5 and sd of ~0.28.
PS: uniformRDD is working correctly as per description with uniform distribution U(0.0, 1.0) and uniformVectorRDD should be generating data with same distribution.