pub fn close_l2<A, S1, S2, D>( test: &ArrayBase<S1, D>, truth: &ArrayBase<S2, D>, rtol: <A as Scalar>::Real, )where A: Scalar + Lapack, S1: Data<Elem = A>, S2: Data<Elem = A>, D: Dimension, <D as Dimension>::Pattern: PartialEq + Debug,
check two arrays are close in L2 norm