Two universally applicable smoothing operations adjustable to meet the specific properties of the given smoothing problem are widely used: 1. Smoothing splines and 2. Smoothing digital convolution filters. The first operation is related to the data vector $r={(r_0,..., r_{n-1})}^T$ with respect to the operations $\Cal{A}$, $\Cal{L}$ and to the smoothing parameter $\alpha$. The resulting function is denoted by $\sigma_\alpha(t)$. The measured sample $r$ is defined on an equally spaced mesh $\Delta=\{t_i=ih\}^{n-1}_{i=0}$ $T=nh$. The smoothed data vector $y$ is then $y=\{\sigma_\alpha(t_i)\}^{n-1}_{i=0}$. The other operation gives $y\in E^n$ computed by $\bold {y=h*r}$, where $\bold *$ stands for the discrete convolution, the running weighted mean by $h$. The main aims of the present contribution: to prove the existence of close interconnection between the two smoothing approaches (Cor. 2.6 and [11]), to develop the transfer function, which characterizes the smoothing spline as a filter in terms of $\alpha$ and $\lambda_{ik}$ (the eigenvalues of the discrete analogue of $Cal {L}$) (Th. 2.5), to develop the reduction ratio between the original and the smoothed data in the same terms (Th. 3.1).
@article{104385, author = {Ji\v r\'\i\ H\v reb\'\i \v cek and Franti\v sek \v Sik and V\'\i t\v ezslav Vesel\'y}, title = {Discrete smoothing splines and digital filtration. Theory and applications}, journal = {Applications of Mathematics}, volume = {35}, year = {1990}, pages = {28-50}, zbl = {0704.65005}, mrnumber = {1039409}, language = {en}, url = {http://dml.mathdoc.fr/item/104385} }
Hřebíček, Jiří; Šik, František; Veselý, Vítězslav. Discrete smoothing splines and digital filtration. Theory and applications. Applications of Mathematics, Tome 35 (1990) pp. 28-50. http://gdmltest.u-ga.fr/item/104385/
A general method for the construction of interpolating or smoothing spline functions, Num. Math. 12 (1968) No. 1, 66-82. (1968) | Article | MR 0249904
Numerical analysis of smoothing splines, (Czech). Proceed. 9-th Symposium on Algorithms ALGORITMY 87, JSMF, Bratislava. 1987, 22-24. (1987)
Spline-Funktionen, Teubner, Stuttgart, 1974. (1974) | MR 0613676
The Fast Fourier Transform, Prentice-Hall, Inc., Englewood Cliffs, New Jersey, 1974. (1974) | Zbl 0375.65052
DFT/FFT and Convolution Algorithms, Wiley Interscience, 1985. (1985)
Smoothing Noisy Data with Spline Functions, Numer. Math. 31 (1979), 377-403. (1979) | Article | MR 0516581
Fast transforms. Algorithms, Analyses, Applications, Acad. Press, New York, London, 1982. (1982) | MR 0696936
Attenuation Factors in Practical Fourier Analysis, Num. Math. 18 (1972), 373-400. (1972) | Article | MR 0305641 | Zbl 0231.65101
Attenuation factors in multivariate Fourier analysis, Num. Math. 51 (1987), 615-629. (1987) | Article | MR 0914342 | Zbl 0639.65079
Digital convolution filters and smoothing splines, Proceed. 2nd ISNA (I. Marek, ed.), Prague 1987, Teubner, Leipzig, 1988, 187-193. (1987) | MR 1171704
How to choose the smoothing parameter of a periodic smoothing spline, (to appear).
Smoothing splines and digital filtration, Research Report, Czechoslovak Academy of Sciences, Institute of Physical Metallurgy, Brno, 1987. (1987)
Approximate methods of higher analysis, (in Russian). 4. ed. Moskva, 1952. (1952) | MR 0106537
Approximation et Optimisation, Hermann, Paris, 1972. (1972) | MR 0467080 | Zbl 0238.90058
Interpolation on uniform meshes by the translates of one function and related attenuation factors, Math. Comput. 37 (1981) No. 156, 403 - 416. (1981) | Article | MR 0628704 | Zbl 0517.42004
A survey of matrix theory and matrix inequalities, Boston 1964 (Russian translation, Nauka, Moskva, 1972). (1964) | MR 0349699
Fast Fourier Transform and Convolution Algorithms, 2nd ed., Springer, Berlin, Heidelberg, New York, 1982. (1982) | MR 0606376
Spline-Functions: Theory, Algorithms, Programs, (in Russian). Nauka, Novosibirsk, 1983. (1983) | MR 0721970 | Zbl 0529.41013
Smoothing by discrete splines and digital convolution filters, (Czech). Proceed Conf. Numer. Methods in the Physical Metallurgy (J. Hřebíček, ed.) Blansko 1988, ÚFM ČSAV Brno 1988, 62-70. (1988)