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