--- title: "Spatial Heterogeneity Explanation(GOZH & LESH)" output: rmarkdown::html_vignette vignette: > %\VignetteIndexEntry{shegd} %\VignetteEngine{knitr::rmarkdown} %\VignetteEncoding{UTF-8} --- The [**GOZH**(geographically optimal zones-based heterogeneity) model](https://doi.org/10.1016/j.isprsjprs.2022.01.009) generates the optimal spatial zone based on the binary classification of the decision tree and then calculates the power of determinants. The [**LESH**(locally explained heterogeneity model)](https://doi.org/10.1080/17538947.2023.2271883) based on GOZH model and combined with additive shapely theory to reasonably allocate variable interaction's power of determinants. In this vignette, we use `ndvi` data in `gdverse` package to demonstrate the *spatial heterogeneity explanation* based on **GOZH** and **LESH** model. ### Load data and package ``` r library(tidyverse) library(gdverse) data("ndvi") head(ndvi) ## # A tibble: 6 × 7 ## NDVIchange Climatezone Mining Tempchange Precipitation GDP Popdensity ## ## 1 0.116 Bwk low 0.256 237. 12.6 1.45 ## 2 0.0178 Bwk low 0.273 214. 2.69 0.801 ## 3 0.138 Bsk low 0.302 449. 20.1 11.5 ## 4 0.00439 Bwk low 0.383 213. 0 0.0462 ## 5 0.00316 Bwk low 0.357 205. 0 0.0748 ## 6 0.00838 Bwk low 0.338 201. 0 0.549 ``` ### Univariate power of determinants detection ``` r gozh.uvi = gozh(NDVIchange ~ ., data = ndvi) gozh.uvi ## GOZH Model ## *** Factor Detector ## ## | variable | Q-statistic | P-value | ## |:-------------:|:-----------:|:--------:| ## | Precipitation | 0.87255056 | 4.52e-10 | ## | Climatezone | 0.82129550 | 2.50e-10 | ## | Tempchange | 0.33324945 | 1.12e-10 | ## | Popdensity | 0.22321863 | 3.00e-10 | ## | Mining | 0.13982859 | 6.00e-11 | ## | GDP | 0.09170153 | 3.96e-10 | plot(gozh.uvi) ``` ![](../man/figures/shegd/gozh_uni-1.png) ### Variable interaction detection ``` r gozh.bi = gozh(NDVIchange ~ ., data = ndvi, type = 'interaction') gozh.bi ## GOZH Model ## *** Interaction Detector ## ## | Interactive variable | Interaction | ## |:---------------------------:|:------------------:| ## | Climatezone ∩ Mining | Weaken, uni- | ## | Climatezone ∩ Tempchange | Weaken, uni- | ## | Climatezone ∩ Precipitation | Enhance, bi- | ## | Climatezone ∩ GDP | Enhance, bi- | ## | Climatezone ∩ Popdensity | Enhance, bi- | ## | Mining ∩ Tempchange | Enhance, bi- | ## | Mining ∩ Precipitation | Weaken, uni- | ## | Mining ∩ GDP | Enhance, bi- | ## | Mining ∩ Popdensity | Enhance, bi- | ## | Tempchange ∩ Precipitation | Enhance, bi- | ## | Tempchange ∩ GDP | Enhance, nonlinear | ## | Tempchange ∩ Popdensity | Enhance, bi- | ## | Precipitation ∩ GDP | Enhance, bi- | ## | Precipitation ∩ Popdensity | Enhance, bi- | ## | GDP ∩ Popdensity | Weaken, uni- | plot(gozh.bi) ``` ![](../man/figures/shegd/gozh_bi-1.png) ### Variable interaction contribution ``` r lesh.m = lesh(NDVIchange ~ ., data = ndvi, cores = 6) lesh.m ## *** Spatial Interaction Association Detector ## LESH Model ## ## | Interactive variable | Interaction | ## |:---------------------------:|:------------------:| ## | Climatezone ∩ Mining | Weaken, uni- | ## | Climatezone ∩ Tempchange | Weaken, uni- | ## | Climatezone ∩ Precipitation | Enhance, bi- | ## | Climatezone ∩ GDP | Enhance, bi- | ## | Climatezone ∩ Popdensity | Enhance, bi- | ## | Mining ∩ Tempchange | Enhance, bi- | ## | Mining ∩ Precipitation | Weaken, uni- | ## | Mining ∩ GDP | Enhance, bi- | ## | Mining ∩ Popdensity | Enhance, bi- | ## | Tempchange ∩ Precipitation | Enhance, bi- | ## | Tempchange ∩ GDP | Enhance, nonlinear | ## | Tempchange ∩ Popdensity | Enhance, bi- | ## | Precipitation ∩ GDP | Enhance, bi- | ## | Precipitation ∩ Popdensity | Enhance, bi- | ## | GDP ∩ Popdensity | Weaken, uni- | plot(lesh.m, pie = TRUE, scatter = TRUE) ``` ![](../man/figures/shegd/lesh-1.png) Compared to **GOZH Interaction Detector**, **LESH** only has a decomposition of the interactive contribution of variables, and the rest remains consistent. gdverse supports modifications to the default ploting results, such as adding subfigure annotations and adjusting the size of the text on the x-y axis: ``` r plot(lesh.m, pie = TRUE, scatter = TRUE, pielegend_x = 0.98, pielegend_y = 0.15) + patchwork::plot_annotation(tag_levels = 'a', tag_prefix = '(', tag_suffix = ')', tag_sep = '', theme = theme(plot.tag = element_text(family = "serif"))) & ggplot2::theme(axis.text.y = element_text(family = 'serif',size = 15), axis.text.x = element_text(family = 'serif',size = 15, angle = 30,vjust = 0.85,hjust = 0.75), axis.title = element_text(family = 'serif',size = 15)) ``` ![](../man/figures/shegd/lesh_own-1.png) And you can only look at the contribution part of the variable interaction: ``` r plot(lesh.m, pie = TRUE, scatter = FALSE) ``` ![](../man/figures/shegd/lesh_only-1.png) By accessing the concrete result through `lesh.m$interaction`, which returns a `tibble`. ``` r lesh.m$interaction ## # A tibble: 15 × 8 ## variable1 variable2 Interaction `Variable1 Q-statistics` Variable2 Q-statisti…¹ ## ## 1 Climatezone Mining Weaken, uni- 0.821 0.140 ## 2 Climatezone Tempchange Weaken, uni- 0.821 0.333 ## 3 Climatezone Precipitation Enhance, bi- 0.821 0.873 ## 4 Climatezone GDP Enhance, bi- 0.821 0.0917 ## 5 Climatezone Popdensity Enhance, bi- 0.821 0.223 ## 6 Mining Tempchange Enhance, bi- 0.140 0.333 ## 7 Mining Precipitation Weaken, uni- 0.140 0.873 ## 8 Mining GDP Enhance, bi- 0.140 0.0917 ## 9 Mining Popdensity Enhance, bi- 0.140 0.223 ## 10 Tempchange Precipitation Enhance, bi- 0.333 0.873 ## 11 Tempchange GDP Enhance, nonlinear 0.333 0.0917 ## 12 Tempchange Popdensity Enhance, bi- 0.333 0.223 ## 13 Precipitation GDP Enhance, bi- 0.873 0.0917 ## 14 Precipitation Popdensity Enhance, bi- 0.873 0.223 ## 15 GDP Popdensity Weaken, uni- 0.0917 0.223 ## # ℹ abbreviated name: ¹​`Variable2 Q-statistics` ## # ℹ 3 more variables: `Variable1 and Variable2 interact Q-statistics` , ## # `Variable1 SPD` , `Variable2 SPD` ``` Use `lesh.m$spd_lesh` to access the SHAP power of determinants: ``` r lesh.m$spd_lesh ## # A tibble: 6 × 2 ## variable spd_theta ## ## 1 Precipitation 0.218 ## 2 Climatezone 0.176 ## 3 Tempchange 0.0482 ## 4 Popdensity 0.0262 ## 5 Mining 0.0158 ## 6 GDP 0.0115 ```