Rose diagrams for spherical (3-D directional) data

Draws a set of rose diagrams for a sample of 3-D orientations (lines or planes) using ggplot2. Petal lengths are scaled to the square root of frequency so that petal area is proportional to count. Depending on the show argument, up to five diagrams are returned: strike (bimodal, 0°–360° mirrored), dip direction (0°–360°), dip angle (0°–90°), trend (0°–360°), and plunge (0°–90°). Optionally overlays the mean orientation; the dominant eigenvector (V1 for clustered data, V3 for girdle distributions) is used as the mean.

Usage

rose_diag_spher(
  trd,
  plg,
  data = NULL,
  conf.level = 0.95,
  width1 = 20,
  width2 = 5,
  alpha = 0.7,
  fill.col = "blue",
  mean.col = "red",
  type = c("line", "dir", "strike"),
  show = "all",
  show.mean = T
)

Arguments

trd

Numeric vector of trend / dip-direction / strike values in degrees, or an unquoted column name when data is supplied.

plg

Numeric vector of plunge / dip values in degrees, or an unquoted column name when data is supplied.

data

A data frame (or tibble) containing the columns referenced by trd and plg. Default NULL (use vectors directly).

conf.level

Numeric. Confidence level for mean direction statistics shown in the subtitles. Default 0.95.

width1

Numeric. Bin width in degrees for the azimuthal diagrams (strike, dip direction, trend). Default 20.

width2

Numeric. Bin width in degrees for the inclination diagrams (dip angle, plunge). Default 5.

alpha

Numeric. Transparency of the petal fill (0 = fully transparent, 1 = fully opaque). Default 0.7.

fill.col

Character. Fill colour of the petals. Default "blue".

mean.col

Character. Colour of the mean-direction line(s). Default "red".

type

Character. How to interpret the input orientations:

"line": (default) Trend and plunge of a lineation.
"dir": Dip direction and dip angle of a plane (converted internally to the pole before computing the mean).
"strike": Strike (right-hand rule) and dip angle of a plane (converted internally to the pole before computing the mean).

show

Character vector selecting which diagrams to return. Use "all" (default) for all five, or any subset of c("strike", "dir", "dip", "trend", "plunge").

show.mean

Logical. If TRUE (default) a radial line is drawn at the mean orientation and the mean value is shown in the subtitle of each diagram; if FALSE neither is added. When the distribution is random (R index dominant) the mean line is suppressed regardless.

Value

A named list of ggplot objects. Names correspond to the selected diagrams: "strike", "dir" (dip direction), "dip" (dip angle), "trend", and/or "plunge". Each plot caption reports the maximum bin percentage and the sample size N.

Examples

# Lines supplied as plain vectors — all five diagrams
set.seed(42)
trds <- runif(50, 40, 80)
plgs <- runif(50, 10, 50)
plots <- rose_diag_spher(trds, plgs)
plots$trend

plots$plunge


# Planes as dip direction / dip, only strike and dip-angle diagrams
rose_diag_spher(trds, plgs, type = "dir",
                show = c("strike", "dip"), fill.col = "steelblue")
#> $strike

#> 
#> $dip

#> 

# From a data frame, no mean line
df <- data.frame(dip_direction = trds, dip = plgs)
rose_diag_spher(dip_direction, dip, data = df,
                type = "dir", show.mean = FALSE)
#> $strike

#> 
#> $dir

#> 
#> $dip

#> 
#> $trend

#> 
#> $plunge

#>

Rose diagrams for spherical (3-D directional) data

Usage

Arguments

Value

See also

Examples