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Plot spherical densities in a stereonet

Source: R/stereonet_contours.R
stereo_contour.Rd

Kamb counts and densities on the sphere. contour plots the contour lines, contourf displays a contour plot with the areas between the contours filled, and image creates a dense grid of colored rectangles.

Usage

# S3 method for class 'spherical'
contour(
  x,
  add = FALSE,
  density.params = list(),
  nlevels = 10L,
  col.palette = viridis::viridis,
  col = NULL,
  col.params = list(),
  ...
)

contourf(
  x,
  add = FALSE,
  density.params = list(),
  nlevels = 10L,
  col.palette = viridis::viridis,
  col.params = list()
)

# S3 method for class 'spherical'
image(
  x,
  add = FALSE,
  density.params = list(),
  nlevels = 10L,
  col.palette = viridis::viridis,
  col.params = list(),
  ...
)

Arguments

x

object of class "Vec3", "Line", "Plane" or 'spherical.density' (for plotting only).

add

logical. Whether the contours should be added to an existing plot.

density.params

list of parameters passed to density.spherical

nlevels

integer. Number of contour levels for plotting

col.palette

a color palette function to be used to assign colors in the plot.

col

colour(s) for the contour lines drawn. If NULL, lines are color based on col.palette.

col.params

list. Arguments passed to col.palette

...

optional parameters passed to graphics::image() or graphics::contour().

Value

list containing the stereographic x and coordinates of of the grid, the counts, and the density.

See also

count_points(), density

Examples

set.seed(20250411)
x <- rfb(100, mu = Line(120, 10), k = 5, A = diag(c(-1, 0, 1)))

contour(x)


contourf(x,
  col.params = list(direction = -1, begin = .05, end = .95, alpha = .75)
)
stereo_point(x, col = "black", pch = 21)


image(x)
stereo_point(x, col = "lightgrey", pch = 21)



# complete example:
par(mfrow = c(1, 2))
wp <- 6 / ifelse(is.na(example_planes$quality), 6, example_planes$quality)
my_planes <- Plane(example_planes$dipdir, example_planes$dip)
fabric_p <- or_shape_params(my_planes)$Vollmer["D"]
my_planes_eig <- eigen(my_planes)

stereoplot(guides = TRUE, col = "grey96")
points(my_planes, col = "grey", pch = 16, cex = .5)
contour(my_planes, add = TRUE, weights = wp)
points(my_planes_eig$vectors[3, ], col = "black", pch = 16)
lines(my_planes_eig$vectors[3, ], d = 90, col = "black", pch = 16)
#> Error in stereo_smallcircle(x, d = ang, ...): formal argument "d" matched by multiple actual arguments
title(
  main = "Planes",
  sub = paste0(
    "N: ", nrow(my_planes), " | Fabric strength: ", round(fabric_p, 2),
    "\nLambert equal area, lower hemisphere projection"
  )
)

my_lines <- Line(example_lines$trend, example_lines$plunge)
wl <- 6 / ifelse(is.na(example_lines$quality), 6, example_lines$quality)
fabric_l <- or_shape_params(my_lines)$Vollmer["D"]

stereoplot(guides = TRUE, col = "grey96")
points(my_lines, col = "grey", pch = 16, cex = .5)
contour(my_lines, add = TRUE, weights = wl)
points(mean(my_lines, w = wl), col = "black", pch = 16)
title(
  main = "Lines",
  sub = paste0(
    "N: ", nrow(my_lines), " | Fabric strength: ", round(fabric_l, 2),
    "\nLambert equal area, lower hemisphere projection"
  )
)