rvvar computes the means of the simulations
of all individual components of a random vector (rv) object.That is, rvvar applies the function var to
the vector of simulations of each component of x,
thus computing "columnwise" variances of the
matrix of simulations of x.
rvsd applies the function sd to
the vector of simulations of each component of x,
thus computing "columnwise" standard deviations of the
matrix of simulations of x.