arcdist

This function calculates the shortest arc distance between two points.

Implementation of icosahedral grids in three dimensions. The spherical-triangular tessellation can be set to create grids with custom resolutions. Both the primary triangular and their inverted penta-hexagonal grids can be calculated. Additional functions are provided that allow plotting of the grids and associated data, the interaction of the grids with other raster and vector objects, and treating the grids as a graphs.

Adam Kocsis

icosa

Global Triangular and Penta-Hexagonal Grids Based on Tessellated
Icosahedra

Adam T. Kocsis

Deutsche Forschungsgemeinschaft 

FAU GeoZentrum Nordbayern 

arcdist function

<dl><dt>p1</dt>
<dd>(<code>numeric</code>) Vector, XYZ or longitude-latitude coordinates of the first point along the arc.</dd>
<dt>p2</dt>
<dd>(<code>numeric</code>) Vector, XYZ or longitude-latitude coordinates of the last point along the arc.</dd>
<dt>output</dt>
<dd>(<code>character</code>) The type of the output value. <code>"distance"</code> will give the distance
in the metric that was fed to the function for the coordinates or the radius.
<code>"deg"</code> will output the the distance in degrees, <code>"rad"</code> will do
so in radians.</dd>
<dt>origin</dt>
<dd>(<code>numeric</code>) Vector, the center of the circle in XYZ coordinates (default is <code>c(0,0,0)</code>).</dd>
<dt>radius</dt>
<dd>(<code>numeric</code>) The radius of the circle in case the input points have polar coordinates only.
Unused when XYZ coordinates are entered. Defaults to the authalic radius of Earth ca. 6371.007km.</dd></dl>

Arguments

Calculation of distances along arcs — arcdist

<dl>

<dt>p1</dt>
<dd>(<code>numeric</code>) Vector, XYZ or longitude-latitude coordinates of the first point along the arc.</dd>


<dt>p2</dt>
<dd>(<code>numeric</code>) Vector, XYZ or longitude-latitude coordinates of the last point along the arc.</dd>


<dt>output</dt>
<dd>(<code>character</code>) The type of the output value. <code>"distance"</code> will give the distance
in the metric that was fed to the function for the coordinates or the radius.
<code>"deg"</code> will output the the distance in degrees, <code>"rad"</code> will do
so in radians.</dd>


<dt>origin</dt>
<dd>(<code>numeric</code>) Vector, the center of the circle in XYZ coordinates (default is <code>c(0,0,0)</code>).</dd>


<dt>radius</dt>
<dd>(<code>numeric</code>) The radius of the circle in case the input points have polar coordinates only.
Unused when XYZ coordinates are entered. Defaults to the authalic radius of Earth ca. 6371.007km.</dd>

</dl>

arcdist: Calculation of distances along arcs

Description

Usage

Value

Arguments

Examples