Rbar

Given \(n\) circular or spherical measurements, the
 length of their normalised vector sum (\(\bar{R}\)) serves as
 a measure of directional concentration.

A collection of datasets and simplified functions for an introductory (geo)statistics module at University College London. Provides functionality for compositional, directional and spatial data, including ternary diagrams, Wulff and Schmidt stereonets, and ordinary kriging interpolation. Implements logistic and (additive and centred) logratio transformations. Computes vector averages and concentration parameters for the von-Mises distribution. Includes a collection of natural and synthetic fractals, and a simulator for deterministic chaos using a magnetic pendulum example. The main purpose of these functions is pedagogical. Researchers can find more complete alternatives for these tools in other packages such as 'compositions', 'robCompositions', 'sp', 'gstat' and 'RFOC'. All the functions are written in plain R, with no compiled code and a minimal number of dependencies. Theoretical background and worked examples are available at <https://tinyurl.com/UCLgeostats/>.

Pieter Vermeesch

geostats

An Introduction to Statistics for Geoscientists

Rbar function

<dl><dt>trd</dt>
<dd>trend angle, in degrees, between 0 and 360 (if
<code>degrees=TRUE</code>) or between 0 and \(2\pi\) (if
<code>degrees=FALSE</code>).</dd>
<dt>plg</dt>
<dd>(optional) plunge angle, in degrees, between 0 and 90
(if <code>degrees=TRUE</code>) or between 0 and \(2\pi\) (if
<code>degrees=FALSE</code>).</dd>
<dt>option</dt>
<dd>scalar. If <code>option=0</code>, then <code>plg</code> is
ignored and the measurements are considered to be circular; if
<code>option=1</code>, then <code>trd</code> is the azimuth and <code>plg</code>
is the dip; if <code>option=2</code>, then <code>trd</code> is the strike
and <code>plg</code> is the dip; if <code>option=3</code> then <code>trd</code>
is the longitude and <code>plg</code> is the latitude.</dd>
<dt>degrees</dt>
<dd><code>TRUE</code> for degrees, <code>FALSE</code> for radians</dd></dl>

Arguments

calculate \(\bar{R}\) — Rbar

<dl>

<dt>trd</dt>
<dd>trend angle, in degrees, between 0 and 360 (if
<code>degrees=TRUE</code>) or between 0 and \(2\pi\) (if
<code>degrees=FALSE</code>).</dd>


<dt>plg</dt>
<dd>(optional) plunge angle, in degrees, between 0 and 90
(if <code>degrees=TRUE</code>) or between 0 and \(2\pi\) (if
<code>degrees=FALSE</code>).</dd>


<dt>option</dt>
<dd>scalar. If <code>option=0</code>, then <code>plg</code> is
ignored and the measurements are considered to be circular; if
<code>option=1</code>, then <code>trd</code> is the azimuth and <code>plg</code>
is the dip; if <code>option=2</code>, then <code>trd</code> is the strike
and <code>plg</code> is the dip; if <code>option=3</code> then <code>trd</code>
is the longitude and <code>plg</code> is the latitude.</dd>


<dt>degrees</dt>
<dd><code>TRUE</code> for degrees, <code>FALSE</code> for radians</dd>

</dl>

Rbar: calculate \(\bar{R}\)

Description

Usage

Value

Arguments

Examples