Extract geometric measures from a shapefile object — shapefile

shapefile_measures() calculates key geometric measures such as the number of points, area, perimeter, width, height, and centroid coordinates for a given shapefile (polygon) object.

Usage

shapefile_measures(shapefile)

Arguments

shapefile: An sf object representing the shapefile. It should contain polygonal geometries for which the measures will be calculated.

Value

A modified sf object with added columns for:

xcoord: The x-coordinate of the centroid.
ycoord: The y-coordinate of the centroid.
area: The area of the polygon (in square units).
perimeter: The perimeter of the polygon (in linear units).
width: The calculated width based on sequential distances between points.
height: The calculated height based on sequential distances between points.

Details

This function processes a single or multi-polygon sf object and computes geometric properties. It calculates distances between points, extracts the centroid coordinates, and computes the area and perimeter of the polygons. The width and height are derived from sequential distances between points.

Examples

if (interactive() && requireNamespace("EBImage")) {
library(pliman)

path_shp <- paste0(image_pliman(), "/soy_shape.rds")
shp <- shapefile_input(path_shp)
shapefile_measures(shp)
}
#>  class       : SpatVector 
#>  geometry    : polygons 
#>  dimensions  : 15, 5  (geometries, attributes)
#>  extent      : 734337.5, 734348.6, 4489013, 4489017  (xmin, xmax, ymin, ymax)
#>  coord. ref. : WGS 72BE / UTM zone 14N (EPSG:32414) 
#>  names       : unique_id block plot_id   row column
#>  type        :     <int> <chr>   <chr> <int>  <int>
#>  values      :         1   B01   P0001     1      1
#>                        2   B01   P0006     2      1
#>                        3   B01   P0007     3      1
#> Simple feature collection with 15 features and 11 fields
#> Geometry type: POLYGON
#> Dimension:     XY
#> Bounding box:  xmin: 734337.5 ymin: 4489013 xmax: 734348.6 ymax: 4489017
#> Projected CRS: WGS 72BE / UTM zone 14N
#> First 10 features:
#>    unique_id block plot_id row column   xcoord  ycoord     area perimeter width height
#> 1          1   B01   P0001   1      1 734339.3 4489016 2.885558  8.895713 3.659  0.789
#> 2          2   B01   P0006   2      1 734339.4 4489016 2.885558  8.895713 3.659  0.789
#> 3          3   B01   P0007   3      1 734339.4 4489015 2.885558  8.895713 3.659  0.789
#> 4          4   B01   P0012   4      1 734339.4 4489014 2.885558  8.895713 3.659  0.789
#> 5          5   B01   P0013   5      1 734339.5 4489013 2.885558  8.895713 3.659  0.789
#> 6          6   B01   P0002   1      2 734343.0 4489016 2.885558  8.895713 3.659  0.789
#> 7          7   B01   P0005   2      2 734343.0 4489016 2.885558  8.895713 3.659  0.789
#> 8          8   B01   P0008   3      2 734343.1 4489015 2.885558  8.895713 3.659  0.789
#> 9          9   B01   P0011   4      2 734343.1 4489014 2.885558  8.895713 3.659  0.789
#> 10        10   B01   P0014   5      2 734343.1 4489013 2.885558  8.895713 3.659  0.789
#>                          geometry
#> 1  POLYGON ((734337.5 4489017,...
#> 2  POLYGON ((734337.5 4489016,...
#> 3  POLYGON ((734337.6 4489015,...
#> 4  POLYGON ((734337.6 4489014,...
#> 5  POLYGON ((734337.6 4489014,...
#> 6  POLYGON ((734341.2 4489017,...
#> 7  POLYGON ((734341.2 4489016,...
#> 8  POLYGON ((734341.2 4489015,...
#> 9  POLYGON ((734341.3 4489014,...
#> 10 POLYGON ((734341.3 4489014,...