Variogram plots for spatial models.

Produces variogram plots for checking spatial trends.

Usage

variogram(
  model.obj,
  row = NA,
  column = NA,
  horizontal = TRUE,
  palette = "default"
)

Arguments

model.obj

An asreml model object.

row

A row variable.

column

A column variable.

horizontal

Logical (default TRUE). The direction the plots are arranged. The default TRUE places the plots above and below, while FALSE will place them side by side.

palette

A string specifying the colour scheme to use for plotting. The default value ("default") is equivalent to "rainbow". Colour blind friendly palettes can also be provided via options "colour blind" (or "color blind", both equivalent to "viridis"), "magma", "inferno", "plasma" or "cividis". The "Spectral" palette from scales::brewer_pal() is also possible.

Value

A ggplot2 object.

References

S. P. Kaluzny, S. C. Vega, T. P. Cardoso, A. A. Shelly, "S+SpatialStats: User’s Manual for Windows® and UNIX®" Springer New York, 2013, p. 68, https://books.google.com.au/books?id=iADkBwAAQBAJ.

A. R. Gilmour, B. R. Cullis, A. P. Verbyla, "Accounting for Natural and Extraneous Variation in the Analysis of Field Experiments." Journal of Agricultural, Biological, and Environmental Statistics 2, no. 3, 1997, pp. 269–93, https://doi.org/10.2307/1400446.

Examples

if (FALSE) {
library(asreml)
oats <- asreml::oats
oats <- oats[order(oats$Row, oats$Column),]
model.asr <- asreml(yield ~ Nitrogen + Variety + Nitrogen:Variety,
                    random = ~ Blocks + Blocks:Wplots,
                    residual = ~ ar1(Row):ar1(Column),
                    data = oats)
variogram(model.asr)
}