Explore directional anisotropy in hydraulic head — ps

Calculates directional variograms and exploratory fitted ranges. The major continuity direction is periodic over 180 degrees and uses gstat's clockwise-from-North convention. Weak evidence is warned and anisotropy is never activated in interpolation unless supplied explicitly.

Usage

ps_anisotropy(
  points,
  formula = Z ~ 1,
  directions = seq(0, 135, by = 45),
  tolerance = 22.5,
  cutoff = NULL,
  width = NULL,
  model = "Sph",
  minimum_pairs = 20,
  validation = FALSE
)

Arguments

points: Groundwater-head points.
formula: Variogram trend formula.
directions: Direction angles.
tolerance: Direction tolerance in degrees.
cutoff, width: Variogram controls.
model: Candidate directional model.
minimum_pairs: Minimum total pairs required for a directional fit.
validation: Optionally request a documented isotropic/anisotropic validation comparison (recorded as not run when no validation design is supplied).

Value

A potentiomap_anisotropy with empirical values, directional fits, major direction, minor-to-major range ratio, and conditions.

Examples

data("synthetic_wells")
pts <- ps_make_points(synthetic_wells, "x", "y", "gw_elevation",
                      "well_id", "EPSG:26916")
a <- ps_anisotropy(pts, minimum_pairs = 5)
#> Warning: 43 lag-direction bin(s) contain fewer than five pairs.
#> Warning: Directional evidence is weak or unstable; no precise anisotropy estimate is justified.
a$summary
#>   major_continuity_direction minor_to_major_range_ratio usable_directions
#> 1                         NA                         NA                 0
#>                   angle_convention
#> 1 clockwise from North; modulo 180
# This exploratory result is not applied automatically.