glob.change {stampr}

glob.change

Description

The function glob.change computes a set of three global change metrics for comparison between two polygon sets. These metrics are outlined in Robertson et al. (2007; Table 4).

Usage

glob.change(T1, T2)

Arguments

T1

a sf object of polygons from time 1.

T2

a sf object of polygons from time 2.

Details

glob.change computes three change metrics, detailed below, that can be used to quantify changes between two polygon sets:

NumRatio – ratio between the number of polygons in T2 and T1;

\mathtt{NumRatio} = \frac{\#(T1)}{\#(T2)}

AreaRatio – ratio between the areas of polygons in T2 and T1;

\mathtt{AreaRatio} = \frac{A(T2)}{A(T1)}

AvgAreaRatio – ratio between the AreaRatio and NumRatio;

\mathtt{AvgAreaRatio} = \frac{\mathtt{AreaRatio}}{\mathtt{NumRatio}} = \frac{\frac{A(T2)}{A(T1)}}{\frac{\#(T1)}{\#(T2)}}

Value

A list object with three elements - Results for the NumRatio, AreaRatio, and AvgAreaRatio metrics.