nnspat-package {nnspat}

nnspat: A package for NN Methods and Their Use in Testing Spatial Patterns

Description

nnspat is a package for computation of spatial pattern tests based on NN relations and generation of various spatial patterns.

Details

The nnspat package contains the functions for segregation/association tests based on nearest neighbor contingency tables (NNCTs), and tests for species correspondence, NN symmetry and reflexivity based on the corresponding contingency tables and functions for generating patterns of segregation, association, uniformity, and various non-random labeling (non-RL) patterns for data in two (or more) dimensions. Applications include plant ecology, disease clustering in epidemiology, and so on. #' See (Dixon (1994); Ceyhan (2010, 2017)).

The nnspat functions

The nnspat functions can be grouped as Auxiliary Functions, NNCT Functions, SCCT Functions, RCT Functions, NN-Symmetry Functions, and the Pattern (Generation) Functions.

Auxiliary Functions

Contains the auxiliary functions used in NN methods, such as indices of NNs, number of shared NNs, Q, R and T values, and so on. In all these functions the data sets are either matrices or data frames.

NNCT Functions

Contains the functions for testing segregation/association using the NNCT. The types of the tests are cell-specific tests, class-specific tests, and overall tests of segregation. See (Ceyhan (2009, 2010)).

SCCT Functions

Contains the functions used for testing species correspondence using the NNCT. The types are NN self and self-sum tests and the overall test of species correspondence. See (Ceyhan (2018)).

RCT Functions

Contains the functions for testing reflexivity using the reflexivity contingency table (RCT). The types are NN self reflexivity and NN mixed-non reflexivity. See (Ceyhan and Bahadir (2017); Bahadir and Ceyhan (2018)).

Symmetry Functions

Contains the functions for testing NN symmetry using the NNCT and Q-symmetry contingency table. The types are NN symmetry and symmetry in shared NN structure. See (Ceyhan (2014)).

Pattern Functions

Contains the functions for generating and visualization of spatial patterns of segregation, association, uniformity clustering and non-RL. See (Ceyhan (2014, 2014)).

References

Bahadir S, Ceyhan E (2018). “On the Number of reflexive and shared nearest neighbor pairs in one-dimensional uniform data.” Probability and Mathematical Statistics, 38(1), 123-137.

Ceyhan E (2009). “Class-Specific Tests of Segregation Based on Nearest Neighbor Contingency Tables.” Statistica Neerlandica, 63(2), 149-182.

Ceyhan E (2010). “On the use of nearest neighbor contingency tables for testing spatial segregation.” Environmental and Ecological Statistics, 17(3), 247-282.

Ceyhan E (2010). “Exact Inference for Testing Spatial Patterns by Nearest Neighbor Contingency Tables.” Journal of Probability and Statistical Science, 8(1), 45-68.

Ceyhan E (2010). “New Tests of Spatial Segregation Based on Nearest Neighbor Contingency Tables.” Scandinavian Journal of Statistics, 37(1), 147-165.

Ceyhan E (2010). “Directional clustering tests based on nearest neighbour contingency tables.” Journal of Nonparametric Statistics, 22(5), 599-616.

Ceyhan E (2014). “Testing Spatial Symmetry Using Contingency Tables Based on Nearest Neighbor Relations.” The Scientific World Journal, Volume 2014, Article ID 698296.

Ceyhan E (2014). “Segregation indices for disease clustering.” Statistics in Medicine, 33(10), 1662-1684.

Ceyhan E (2014). “Simulation and characterization of multi-class spatial patterns from stochastic point processes of randomness, clustering and regularity.” Stochastic Environmental Research and Risk Assessment (SERRA), 38(5), 1277-1306.

Ceyhan E (2017). “Cell-Specific and Post-hoc Spatial Clustering Tests Based on Nearest Neighbor Contingency Tables.” Journal of the Korean Statistical Society, 46(2), 219-245.

Ceyhan E (2018). “A contingency table approach based on nearest neighbor relations for testing self and mixed correspondence.” SORT-Statistics and Operations Research Transactions, 42(2), 125-158.

Ceyhan E, Bahadir S (2017). “Nearest Neighbor Methods for Testing Reflexivity.” Environmental and Ecological Statistics, 24(1), 69-108.

Dixon PM (1994). “Testing spatial segregation using a nearest-neighbor contingency table.” Ecology, 75(7), 1940-1948.