circular_sd_error {tectonicr} | R Documentation |
Standard Error of Mean Direction of Circular Data
Description
Measure of the chance variation expected from sample to sample in estimates
of the mean direction.
It is a parametric estimate of the the circular standard error of the mean direction
by the particular form of the standard error for the von Mises distribution.
The approximated standard error of the mean direction is computed by the mean
resultant length and the MLE concentration parameter \kappa
.
Usage
circular_sd_error(x, w = NULL, axial = TRUE, na.rm = TRUE)
Arguments
x |
numeric vector. Values in degrees. |
w |
(optional) Weights. A vector of positive numbers and of the same
length as |
axial |
logical. Whether the data are axial, i.e. pi-periodical
( |
na.rm |
logical value indicating whether |
Value
numeric
References
N.I. Fisher (1993) Statistical Analysis of Circular Data, Cambridge University Press.
Davis (1986) Statistics and data analysis in geology. 2nd ed., John Wiley & Sons.
See Also
mean_resultant_length()
, circular_mean()
Examples
# Example data from Davis (1986), pp. 316
finland_stria <- c(
23, 27, 53, 58, 64, 83, 85, 88, 93, 99, 100, 105, 113,
113, 114, 117, 121, 123, 125, 126, 126, 126, 127, 127, 128, 128, 129, 132,
132, 132, 134, 135, 137, 144, 145, 145, 146, 153, 155, 155, 155, 157, 163,
165, 171, 172, 179, 181, 186, 190, 212
)
circular_sd_error(finland_stria, axial = FALSE)
data(san_andreas)
data("nuvel1")
PoR <- subset(nuvel1, nuvel1$plate.rot == "na")
sa.por <- PoR_shmax(san_andreas, PoR, "right")
circular_sd_error(sa.por$azi.PoR, w = 1 / san_andreas$unc)