To sample 𝒙 from the truncated multinormal distribution , Hamiltonian Monte Carlo sampling can be used . We generated 10,000 samples and discarded the first 1,000 as burn-in. The impedance can then be obtained from the sampled 𝒙 by matrix multiplication, i.e., 𝒁 = 𝑨𝒙. In the figures in the remainder of the article, the means of DRT and impedance are shown as a black line, while the 3 × σ credible intervals are shown as gray regions.