anisotropyTwave function

Wave anisotropy transformation

Wave anisotropy transformation.

anisotropyTwave(spacepoints, phi1, phi2, beta, theta)

Arguments

• spacepoints: vector of coordinates (2 x d), where d is the number of locations/grid points
• phi1: stretching parameter along the x axis
• phi2: stretching parameter along the y axis
• beta: amplitude of sinusoidal wave
• theta: rotation angle

Examples

## specify coordinates
m = 25
aux <- seq(0, m - 1, length = m)
coord <- expand.grid(aux, aux)

at <- anisotropyTwave(spacepoints = coord,
                     phi1 = 0.5,
                     phi2 = 2,
                     beta = 3,
                     theta = 0)

## visualize transformed coordinate system
aux = data.frame(lon = at[ ,1], lat = at[ ,2], id1 = rep(1:m, each = m), id2 = rep(1:m, m))
ggplot(aux, aes(x = lon, y = lat)) +
geom_path(aes(group = id1)) +
geom_path(aes(group = id2)) +
geom_point(col = 2) +
theme_light()

References

Papalexiou, S.M., Serinaldi, F., Porcu, E. (2021). Advancing Space-Time Simulation of Random Fields: From Storms to Cyclones and Beyond. Water Resources Research, 57, e2020WR029466, tools:::Rd_expr_doi("10.1029/2020WR029466")