Given two continuous numeric variables, calculate the bivariate Local Moran's I.

localmoran_bv(x, y, listw, nsim = 199, scale = TRUE, alternative="two.sided",
 iseed=1L, no_repeat_in_row=FALSE)

Arguments

x

a numeric vector of same length as y.

y

a numeric vector of same length as x.

listw

a listw object for example as created by nb2listw().

nsim

the number of simulations to run.

scale

default TRUE.

alternative

a character string specifying the alternative hypothesis, must be one of "greater" (default), "two.sided", or "less".

iseed

default NULL, used to set the seed for possible parallel RNGs.

no_repeat_in_row

default FALSE, if TRUE, sample conditionally in each row without replacements to avoid duplicate values, https://github.com/r-spatial/spdep/issues/124

Value

a data.frame containing two columns Ib and p_sim containing the local bivariate Moran's I and simulated p-values respectively.

Details

The Bivariate Local Moran, like its global counterpart, evaluates the value of x at observation i with its spatial neighbors' value of y. The value of \(I_i^B\) is xi * Wyi. Or, in simpler words, the local bivariate Moran is the result of multiplying x by the spatial lag of y. Formally it is defined as

\( I_i^B= cx_i\Sigma_j{w_{ij}y_j} \)

References

Anselin, Luc, Ibnu Syabri, and Oleg Smirnov. 2002. “Visualizing Multivariate Spatial Correlation with Dynamically Linked Windows.” In New Tools for Spatial Data Analysis: Proceedings of the Specialist Meeting, edited by Luc Anselin and Sergio Rey. University of California, Santa Barbara: Center for Spatially Integrated Social Science (CSISS).

Author

Josiah Parry josiah.parry@gmail.com

Examples

# load columbus data
columbus <- st_read(system.file("shapes/columbus.shp", package="spData"))
#> Reading layer `columbus' from data source 
#>   `/home/rsb/lib/r_libs/spData/shapes/columbus.shp' using driver `ESRI Shapefile'
#> Simple feature collection with 49 features and 20 fields
#> Geometry type: POLYGON
#> Dimension:     XY
#> Bounding box:  xmin: 5.874907 ymin: 10.78863 xmax: 11.28742 ymax: 14.74245
#> CRS:           NA
nb <- poly2nb(columbus)
listw <- nb2listw(nb)
set.seed(1)
(res <- localmoran_bv(columbus$CRIME, columbus$INC, listw, nsim = 499))
#>                Ibvi        E.Ibvi    Var.Ibvi      Z.Ibvi Pr(z != E(Ibvi))
#>  [1,] -0.8578252210 -1.826370e-02 0.731541578 -0.98159654     3.262987e-01
#>  [2,]  0.1802618568  2.554658e-02 0.334247968  0.26760782     7.890012e-01
#>  [3,]  0.0118856298  7.791116e-03 0.017162929  0.03125407     9.750669e-01
#>  [4,] -0.0163525887 -3.452848e-03 0.005852145 -0.16862558     8.660912e-01
#>  [5,] -0.5037734606  1.811633e-02 0.101966376 -1.63436973     1.021812e-01
#>  [6,] -0.0041841415  1.293651e-02 0.139142736 -0.04589760     9.633919e-01
#>  [7,]  1.5201688711 -1.466392e-04 1.099034279  1.45020069     1.470026e-01
#>  [8,] -0.2016456990  7.471406e-03 0.007231278 -2.45913301     1.392730e-02
#>  [9,]  0.0297432891  1.600490e-03 0.009219518  0.29309821     7.694471e-01
#> [10,] -0.0374203146  1.218906e-03 0.001100110 -1.16495823     2.440359e-01
#> [11,] -1.2368494456  7.720869e-02 0.498286158 -1.86155199     6.266627e-02
#> [12,] -1.2010054212  4.055009e-02 0.266658169 -2.40430022     1.620346e-02
#> [13,] -0.5377131737  1.218864e-02 0.122363375 -1.57202494     1.159448e-01
#> [14,] -0.9879712511  3.048475e-02 0.320475271 -1.79905736     7.200961e-02
#> [15,] -0.6057303757  2.137030e-02 0.102916086 -1.95476986     5.061024e-02
#> [16,] -0.7878039284  1.378587e-02 0.161039891 -1.99749384     4.577156e-02
#> [17,]  0.1379508106  9.352179e-04 0.003351141  2.36686570     1.793944e-02
#> [18,] -0.3253226893  1.066349e-02 0.078469609 -1.19941831     2.303653e-01
#> [19,] -0.3888822685 -7.104732e-06 0.432305953 -0.59144532     5.542221e-01
#> [20,] -0.4544889957  1.367811e-01 0.355060554 -0.99228105     3.210604e-01
#> [21,] -0.0006014046  3.919068e-03 0.031597455 -0.02543067     9.797114e-01
#> [22,] -0.0068813684 -3.664201e-03 0.001242910 -0.09125440     9.272904e-01
#> [23,] -0.8788967496  1.189579e-02 0.289002627 -1.65701209     9.751703e-02
#> [24,] -0.1256865340 -3.048451e-03 0.004692164 -1.79035349     7.339710e-02
#> [25,] -0.9307459211  4.509269e-02 0.303474056 -1.77140234     7.649382e-02
#> [26,] -0.2252775788  1.039843e-02 0.019527743 -1.68651169     9.169728e-02
#> [27,]  0.1413018326 -1.409345e-02 0.236810168  0.31932848     7.494774e-01
#> [28,] -0.7804482928  3.200178e-02 0.184987862 -1.88897002     5.889585e-02
#> [29,] -0.7654416689  5.928648e-02 0.364667175 -1.36572255     1.720261e-01
#> [30,] -0.9074829015  7.597435e-03 0.737090639 -1.06585659     2.864885e-01
#> [31,] -0.5510119267 -1.377557e-03 0.388899970 -0.88136323     3.781213e-01
#> [32,] -1.9581476375  2.561515e-02 0.239115219 -4.05682367     4.974461e-05
#> [33,]  0.0907015890  3.048227e-02 0.043681309  0.28812970     7.732475e-01
#> [34,] -0.4297843082  2.130996e-02 0.104683121 -1.39421250     1.632534e-01
#> [35,]  0.1181174820  6.746380e-04 0.008393054  1.28193663     1.998649e-01
#> [36,] -0.9901007017  2.760845e-02 0.278368628 -1.92891697     5.374117e-02
#> [37,] -0.2195812498 -7.723065e-03 0.032151838 -1.18152344     2.373948e-01
#> [38,] -0.3096268627  3.401135e-02 0.205499338 -0.75804717     4.484227e-01
#> [39,] -0.6090192229  1.689079e-02 0.308320019 -1.12722610     2.596469e-01
#> [40,] -1.2709838927  6.528265e-02 0.216905961 -2.86917707     4.115413e-03
#> [41,] -1.3940681427  9.430182e-02 0.304439982 -2.69749131     6.986411e-03
#> [42,] -0.4820987026  3.961324e-02 0.632999863 -0.65573592     5.119941e-01
#> [43,] -0.0064402410  2.939096e-03 0.001385154 -0.25201308     8.010310e-01
#> [44,]  0.0761664412  2.162964e-02 0.054095662  0.23448142     8.146113e-01
#> [45,] -0.0560342555  7.788766e-03 0.029796273 -0.36973996     7.115763e-01
#> [46,] -0.8249832451 -2.301643e-02 0.673531467 -0.97718648     3.284768e-01
#> [47,] -0.8915318222  2.294960e-02 0.095247718 -2.96310881     3.045489e-03
#> [48,] -0.1282863305 -9.674295e-03 0.061579149 -0.47798241     6.326627e-01
#> [49,]  0.0094888641 -4.828535e-03 0.222107368  0.03037964     9.757643e-01
#>       Pr(z != E(Ibvi)) Sim Pr(folded) Sim
#>  [1,]                0.324          0.162
#>  [2,]                0.880          0.440
#>  [3,]                0.976          0.488
#>  [4,]                0.800          0.400
#>  [5,]                0.112          0.056
#>  [6,]                0.864          0.430
#>  [7,]                0.096          0.048
#>  [8,]                0.004          0.002
#>  [9,]                0.852          0.426
#> [10,]                0.260          0.130
#> [11,]                0.056          0.028
#> [12,]                0.008          0.004
#> [13,]                0.084          0.042
#> [14,]                0.064          0.032
#> [15,]                0.052          0.026
#> [16,]                0.028          0.014
#> [17,]                0.028          0.014
#> [18,]                0.192          0.096
#> [19,]                0.608          0.304
#> [20,]                0.368          0.184
#> [21,]                0.936          0.468
#> [22,]                0.928          0.464
#> [23,]                0.120          0.060
#> [24,]                0.040          0.020
#> [25,]                0.044          0.022
#> [26,]                0.076          0.038
#> [27,]                0.736          0.368
#> [28,]                0.032          0.016
#> [29,]                0.140          0.070
#> [30,]                0.284          0.142
#> [31,]                0.408          0.204
#> [32,]                0.004          0.002
#> [33,]                0.724          0.362
#> [34,]                0.188          0.094
#> [35,]                0.216          0.108
#> [36,]                0.084          0.042
#> [37,]                0.232          0.116
#> [38,]                0.464          0.232
#> [39,]                0.268          0.134
#> [40,]                0.004          0.002
#> [41,]                0.020          0.010
#> [42,]                0.468          0.234
#> [43,]                0.884          0.442
#> [44,]                0.904          0.452
#> [45,]                0.672          0.336
#> [46,]                0.344          0.172
#> [47,]                0.012          0.006
#> [48,]                0.544          0.272
#> [49,]                0.896          0.448
#> attr(,"class")
#> [1] "localmoran" "matrix"     "array"