Total (class) edge (vector data)

This function allows you to calculate the total length of edge of class i in a categorical landscape in vector data format

Usage

vm_c_te(landscape, class_col, count_boundary = TRUE)

Arguments

landscape

the input landscape image,

class_col

the name of the class column of the input landscape

count_boundary

Include landscape boundary in edge length (default: TRUE)

Value

the returned calculated length is in column "value", and this function returns also some important information such as level, class number and metric name. Moreover, the "id" column, although it is just NA here at class level. we need it because the output struture of metrics at class level should correspond to patch level one by one, and then it is more convinient to combine metric values at different levels and compare them.

Details

Total edge for a class includes all edges between that class and other classes. Internal edges between patches of the same class are not counted (they disappear when patches are merged). This is calculated as the perimeter of the union of all patches of that class.

Note: The default differs from landscapemetrics (default: FALSE) because vector polygon boundaries are explicit geometric features. Set count_boundary=FALSE for direct comparison with landscapemetrics results.

Examples

vm_c_te(vector_landscape, "class")
#> # A tibble: 3 × 5
#>   level class id    metric value
#>   <chr> <chr> <chr> <chr>  <dbl>
#> 1 class 1     NA    te       222
#> 2 class 2     NA    te       292
#> 3 class 3     NA    te       360
vm_c_te(vector_landscape, "class", count_boundary = FALSE)
#> # A tibble: 3 × 5
#>   level class id    metric value
#>   <chr> <chr> <chr> <chr>  <dbl>
#> 1 class 1     NA    te       190
#> 2 class 2     NA    te       275
#> 3 class 3     NA    te       289