Unlike the mathematical formulations of scientific and engineering problems, which virtually lead to exact results, concrete numerical calculations are affected by inherent inaccuracies. The errors occurring in computations can be both genuinely numerical and nonspecific in nature. The nonspecific errors are rather diverse and may comprise, among others, errors related to the formulation of the problem, the employed methodology, or the input data. In their turn, the specific numerical errors, which are of primary concern to numerical analysis, include roundoff and truncation errors.