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Mean strain ellipse after Ramsay (1967)

Source: R/strain_analysis.R
mean_strain_ellipse_ramsay.Rd

Mean strain ellipse after Ramsay (1967)

Usage

mean_strain_ellipse_ramsay(
  r,
  phi = NULL,
  boot = TRUE,
  resamples = 1000,
  boot.values = FALSE
)

Arguments

r

numeric. Aspect ratio of deformed object (long axis / short axis)

phi

numeric. Orientation of long axis of deformed object (in degrees)

boot

logical. Whether a 95% confidence interval from on bootstrapping should be calculated. TRUE by default.

resamples

integer. Number of bootstrap resamples (1000 by default). Ignored when boot = FALSE.

boot.values

logical. Whether the bootstrapped R and phi values should be added to the output. FALSE by default.

Value

list. R aspect ratio of strain ellipse, Ri initial aspect ratio, Fl the fluctuation angle (after Ramsay 1967), and phi the mean orientation of the strain ellipse long axis. If boot=TRUE, then the bootstrapped 95% confidence interval for the values are added. If boot.values=TRUE, a matrix containing the bootstrapped R and phi values are added.

References

Ramsay (1976), Folding and Fracturing of Rocks, McGraw-Hill Book Company.

Ramsay, J. G., & Huber, M. I. (1983). The Techniques of Modern Structural Geology: Strain Analyses (Vol. 1). London: Academic Press.

See also

mean_strain_ellipse()

Examples

data(ramsay)
mean_strain_ellipse_ramsay(ramsay[, "R"], ramsay[, "phi"])
#> $R
#> [1] 1.850135
#> 
#> $Ri
#> [1] 1.762033
#> 
#> $Fl
#> [1] 65.79613
#> 
#> $phi
#> [1] 25.83207
#> 
#> $R_CI
#> [1] 1.633095 1.944634
#> 
#> $Ri_CI
#> [1] 1.540705 1.762033
#> 
#> $Fl_CI
#> [1] 46.67333 65.79613
#> 
#> $phi_CI
#> [1] 24.86458 26.85261
#>