Create contours and a contour-level inventory — ps

Extracts contour lines from a one-layer surface. The default remains a line SpatVector. The opt-in result inventories every requested level, its relation to the finite surface range, returned feature count, and any omission. Open lines are not converted to polygons.

Usage

ps_contours(
  surface,
  interval = 1,
  levels = NULL,
  return = c("contours", "result")
)

Arguments

surface: One-layer potentiometric-surface SpatRaster.
interval: Positive contour interval in surface units.
levels: Optional finite explicit contour levels. interval is ignored when these are supplied.
return: Either "contours" for the backward-compatible SpatVector or "result" for a structured inventory.

Value

A line SpatVector, or a potentiomap_contour_result containing contours, manifest, surface_range, call, interval, levels, warnings, and package_version.

Examples

data("synthetic_wells")
pts <- ps_make_points(synthetic_wells, "x", "y", "gw_elevation",
                      "well_id", "EPSG:26916")
surface <- ps_interpolate(pts, methods = "IDW", grid_res = 150)$IDW
result <- ps_contours(surface, levels = c(165, 168, 171), return = "result")
result$manifest
#>   requested_level surface_minimum surface_maximum       level_relation
#> 1             165        164.2773        171.1632 within_surface_range
#> 2             168        164.2773        171.1632 within_surface_range
#> 3             171        164.2773        171.1632 within_surface_range
#>   returned_status returned_feature_count omission_reason
#> 1        returned                      1                
#> 2        returned                      1                
#> 3        returned                      1