Abstract
We consider kernel-based non-parametric estimation of second-order product densities of spatial point patterns. We present a new family of optimal and positive kernels that shows less variance and more flexibility than optimal kernels. This family generalises most of the classical and widely used kernel functions, such as Box or Epanechnikov kernels. We propose an alternative asymptotically unbiased estimator for the second-order product density function, and compare the performance of the estimator for several members of the family of optimal and positive kernels through MISE and relative efficiency. We present a simulation study to analyse the behaviour of such kernel functions, for three different spatial structures, for which we know the exact analytical form of the product density, and under small sample sizes. Some known datasets are revisited, and we also analyse the IMD dataset in the Rhineland Regional Council in Germany.








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References
Akaike H (1954) An approximation to the density function. Ann Inst Stat Math 6:127–132
Baddeley A, Gregori P, Mateu J, Stoica R, Stoyan D (2006) Case studies in spatial point process modeling, vol 185. Springer, New York
Baddeley A, Turner R (1995) Spatstat: an R package for analyzing spatial point patterns. J Stat Softw 12(06):1–42
Baddeley AJ, Møller J, Waagepetersen R (2000) Non- and semi-parametric estimation of interaction in inhomogeneous point patterns. Stat Neerl 54:329–350
Berlinet A, Thomas-Agnan C (2004) Reproducing kernel Hilbert spaces in probability and statistics. Springer, New York
Brillinger DR (1975) Statistical inference for stationary point process. In: Stochastic processes and related topics. Academic Press, New York, pp 55–99
Cliff AD, Ord JK (1981) Spatial processes: models and applications. Poon Limited, London
Cline DBH (1988) Admissibile kernel estimators of a multivariate density. Ann Stat 16:1421–1427
Comas C, Mateu J (2011) Statistical inference for Gibbs point processes based on field observations. Stoch Environ Res Risk Assess 25:287–300
Comas C, Palahi M, Pukkala T, Mateu J (2009) Characterising forest spatial structure through inhomogeneous second order characteristics. Stoch Environ Res Risk Assess 23:387–397
Cressie N (1993) Statistics for spatial data. Wiley, New York (Revised Edition)
Daley DJ, Vere-Jones D (2003) An introduction to the theory of point processes, vol. I: Elementary theory and methods. Springer, New York
De Forest EL (1873) On some methods of interpolation applicable to the graduation of irregular series, such as tables of mortality, & c., & c. In: Annual report of the Board of Regents of the Smithsonian Institution, vol. 1871. Washington Smithsonian Institution, Washington, pp 275–340
Diggle PJ (1983) Statistical analysis of spatial point patterns. Academic Press, London
Diggle PJ (1985) A kernel method for smoothing point process data. J R Stat Soc Ser C (Appl Stat) 34:138–147
Diggle PJ (2003) Statistical analysis of spatial point patterns. Arnold, London
Diggle PJ, Richardson S (1993) Epidemiological studies of industrial pollutants: an introduction. Int Stat Rev/Revue Internationale de Statistique 61:203–206
Doguwa SI (1990) On edge-corrected kernel-based pair-correlation function estimators for point processes. Biom J 32:95–106
Efromovich S (1999) Nonparametric curve estimation methods, theory, and applications. Springer, New York
Epanechnikov VA (1969) Non-parametric estimation of a multivariate probability density read more. Theory Probab Appl 14:153–158
Falk M (1983) Relative efficiency and deficiency of kernel type estimators of smooth distribution functions. Stat Neerl 37:73–83
Fan J, Marron JS (1994) Fast implementations of nonparametric curve estimators. J Comput Graph Stat 3:35–56
Fiksel T (1988) Edge-corrected density estimators for point processes. Statistics 19:67–75
Gasser T, Müller HG (1984) Estimating regression functions and their derivatives by the kernel method. Scand J Stat 11:171–185
Gasser T, Müller HG, Mammitzsch V (1985) Kernels for nonparametric curve estimation. J R Stat Soc Ser B (Methodological) 47:238–252
Gasser T, Rosenblatt M (1979) Kernel estimation of regression functions. In: Smoothing techniques for curve estimation. Springer, Berlin, pp 23–68
Gelfand A, Diggle P, Guttorp P, Fuentes M (2010) Handbook of spatial statistics. Chapman & Hall/CRC Press, Boca Raton
Goodall D (1952) Some considerations in the use of point quadrats for the analysis of vegetation. Aust J Biol Sci 5:1–41
Gram J (1883) Ueber die entwickelung reeller functionen in reihen mittelst der methode der kleinsten quadrate. Journal für die reine und angewandte Mathematik 94:41–73
Guan Y (2007) A least-squares cross-validation bandwidth selection approach in pair correlation function estimations. Stat Probab Lett 77:1722–1729
Hart JD (1997) Nonparametric smoothing and lack-of-fit tests. Springer, New York
Hodder I, Orton C (1976) Spatial analysis in archaeology. Cambridge University Press, Cambridge
Hoem JM (1983) The reticent trio: some little-known early discoveries in life insurance mathematics by L. H. F. Oppermann, T. N. Thiele and J. P. Gram. Int Stat Rev 51:213–221
Illian J, Penttinen A, Stoyan H, Stoyan D (2008) Statistical analysis and modelling of spatial point patterns. Wiley, Chichester
Juan P, Mateu J, Saez M (2012) Pinpointing spatio-temporal interactions in wildfire patterns. Stoch Environ Res Risk Assess 26:1131–1150
Krickeberg K (1982) Processus ponctuels en statistique. In: Ecole d’Eté de Probabilités de Saint-Flour X—1980. Springer, Berlin, pp 205–313
Luke YL (1969) The special functions and their approximations. Academic Press, New York
Macaulay FR (1931) The smoothing of economic time series, curve fitting and graduation. In: The smoothing of time series. The National Bureau of Economic Research, pp 31–42
Mammitzsch V (1984) On the asymptotically optimal solution within a certain class of kernel type estimators. Stat Decisions 2:247–255
Marron J, Nolan D (1988) Canonical kernels for density estimation. Stat Probab Lett 7:195–199
Messer K, Goldstein L (1993) A new class of kernels for nonparametric curve estimation. Ann Stat 21:179–195
Meyer S, Elias J, Höhle M (2012) A space–time conditional intensity model for invasive meningococcal disease occurrence. Biometrics 68(2):607–616
Møller J, Waagepetersen RP (2004) Statistical inference and simulation for spatial point processes. Chapman and Hall/CRC, Boca Raton
Müller HG (1985) On the number of sign changes of a real function. Periodica Math Hung 16:209–213
Müller HG, Gasser T (1979) Optimal convergence properties of kernel estimates of derivatives of a density function. In: Gasser T, Rosenblatt M (eds) Smoothing techniques for curve estimation, vol. 757, Lecture notes in mathematics. Springer, Berlin, pp 144–154
Nadaraya EA (1964) On estimating regression. Theory Probab Appl 9:141–142
Neyman J, Scott EL (1958) Statistical approach to problems of cosmology. J R Stat Soc Ser B (Methodological) 20:1–43
Ogata Y (1998) Space–time point-process models for earthquake occurrences. Ann Inst Stat Math 50:379–402
Ohser J (1991) On estimation of pair correlation functions. Res Inform 4:147–152
Ohser J, Mücklich F (2000) Statistical analysis of microstructures in materials science. Wiley, New York
Parzen E (1962) On estimation of a probability density function and mode. Ann Math Stat 33:1065–1076
Pielou EC (1977) Mathematical ecology. Wiley-Interscience Publication. Wiley, New York
Ripley BD (1981) Spatial statistics. Wiley, New York
Ripley BD (ed) (1989) Statistical inference for spatial processes. Cambridge University Press, New York
Rosenblatt M (1956) Remarks on some nonparametric estimates of a density function. Ann Math Stat 27(3):832–837
Rosenblatt M (1971) Curve estimates. Ann Math Stat 42:1815–1842
Sacks J, Ylvisaker D (1981) Asymptotically optimum kernels for density estimation at a point. Ann Stat 9:334–346
Schoenberg FP, Brillinger DR, Guttorp P (2006) Point processes, spatial–temporal. Wiley, Chichester, pp 2885–2886
Silverman B (ed) (1986) Density estimation for statistics and data analysis. Chapman and Hall/CRC, London
Silverman BW (1978) Distances on circles, toruses and spheres. J Appl Probab 15:136–143
Stoyan D, Bertram U, Wendrock H (1993) Estimation variances for estimators of product densities and pair correlation functions of planar point processes. Ann Inst Stat Math 45(2):211–221
Stoyan D, Kendall WS, Mecke J (1987) Stochastic geometry and its applications, vol 8, 2nd edn. Wiley, Chichester
Stoyan D, Stoyan H (1994) Fractals. Random shapes and point fields. Wiley, New York
Stoyan D, Stoyan H (2000) Improving ratio estimators of second order point process characteristics. Scand J Stat 27:641–656
Wand M (2013) KernSmooth: functions for kernel smoothing for Wand & Jones (1995) (2013). R package version 2.23-10. http://CRAN.R-project.org/package=KernSmooth
Watson GS (1964) Smooth regression analysis. Sankhyā 26:359–372
Watson GS, Leadbetter MR (1963) On the estimation of the probability density, i. Ann Math Statist 34:480–491
Woolhouse WSB (1870) Explanation of a new method of adjusting mortality tables; with some observations upon Mr. Makeham’s modification of Gompertz’s theory. J Inst Actuaries Assur Mag 15:389–410
Acknowledgments
The research work of Francisco J. Rodríguez-Cortés’s was supported by Grant P1-1B2012-52 and Jorge Mateu’s research was supported by Grant MTM2010-14961 from Ministry of Education. We also would like to thank Jonatan A. González for their valuable advice. We sincerely thank two referees and the Associate Editor for helpful comments and suggestions which led to improve the paper.
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Rodríguez-Cortés, F.J., Mateu, J. Second-order smoothing of spatial point patterns with small sample sizes: a family of kernels. Stoch Environ Res Risk Assess 29, 295–308 (2015). https://doi.org/10.1007/s00477-014-0944-x
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DOI: https://doi.org/10.1007/s00477-014-0944-x

