Compute stereonet coordinates for a line (degrees)

Converts the trend and plunge of one or more lines to their \((x, y)\) positions on an equal-area or equal-angle stereonet of unit radius. Vectorised over trd and plg.

Usage

StCoordLineD(trd, plg, wulff = F)

Arguments

trd

Numeric vector. Trend of the line(s) in degrees.

plg

Numeric vector. Plunge of the line(s) in degrees. Lines plunging into the upper hemisphere (negative plunge) are automatically reflected.

wulff

Logical. If TRUE uses an equal-angle (Wulff) projection; if FALSE (default) uses an equal-area (Schmidt) projection.

Value

A tibble with columns xp and yp giving the stereonet coordinates for each input line.

References

Allmendinger, R. W., Cardozo, N., & Fisher, D. M. (2012). Structural geology algorithms: Vectors and tensors. Cambridge university press.

See also

Other structural algorithms: Angles(), CartToSphD(), GreatCircleD(), Pole(), Rotate(), SmallCircleD(), SphToCartD(), StPointD()

Examples

StCoordLineD(trd = c(30, 90, 180), plg = c(10, 45, 60))
#> # A tibble: 3 × 2
#>         xp        yp
#>      <dbl>     <dbl>
#> 1 4.55e- 1  7.87e- 1
#> 2 5.41e- 1  3.31e-17
#> 3 4.48e-17 -3.66e- 1
StCoordLineD(trd = 45, plg = 30, wulff = TRUE)
#> # A tibble: 1 × 2
#>      xp    yp
#>   <dbl> <dbl>
#> 1 0.408 0.408