Sample variogram

Creates a sample variogram for a set of effects (e.g., plot errors).

Usage

sample_variogram(df, effect, min.np = 30)

Arguments

df

A data frame with the columns 'col', 'row', and the effects to be plotted.

effect

The name of the effects to be plotted.

min.np

Minimum number of pairs for which semivariances are displayed (default is 30).

Value

A sample variogram with x- and y-axes displaying the row and column displacements, and the z-axis displaying the average semivariances (variogram ordinates) for the effects.

Examples

# Sample variogram of plot errors simulated using a separable first order
# autoregressive (AR1) process.

error_df <- field_trial_error(
  ntraits = 1,
  nenvs = 1,
  spatial.model = "AR1"
)

variogram <- sample_variogram(
  df = error_df,
  effect = "e.Trait1"
)

# Sample variogram
variogram


# Extract the data frame with the column and row displacements, and the
# average semivariances.
variogram_df <- variogram$data