tz_lookup_coords

There are two methods - <code>"fast"</code>, and <code>"accurate"</code>. The <code>"fast"</code> version can
look up many thousands of points very quickly, however when a point is near
a time zone boundary and not near a populated centre, it may return the
incorrect time zone. If accuracy is more important than speed, use
<code>method = "accurate"</code>.

Input latitude and longitude values or an 'sf/sfc' POINT
object and get back the time zone in which they exist. Two methods are implemented.
One is very fast and uses 'Rcpp' in conjunction with data from the 'Javascript' library
(<https://github.com/darkskyapp/tz-lookup-oss/>). This method also works outside of countries'
borders and in international waters, however speed comes at the cost of accuracy - near time
zone borders away from populated centres there is a chance that it will return the incorrect
time zone. The other method is slower but more accurate - it uses the 'sf' package to intersect
points with a detailed map of time zones from here:
<https://github.com/evansiroky/timezone-boundary-builder/>. The package also
contains several utility functions for helping to understand and visualize
time zones, such as listing of world time zones, including information about
daylight savings times and their offsets from UTC. You can also plot a
time zone to visualize the UTC offset over a year and when daylight savings
times are in effect.

Andy Teucher

lutz

Look Up Time Zones of Point Coordinates

Bob Rudis

tz_lookup_coords function

<dl><dt>lat</dt>
<dd>numeric vector of latitudes</dd>
<dt>lon</dt>
<dd>numeric vector of longitudes the same length as <code>x</code></dd>
<dt>method</dt>
<dd>method by which to do the lookup. Either <code>"fast"</code> (default)
or <code>"accurate"</code>.</dd>
<dt>warn</dt>
<dd>By default, if <code>method = "fast"</code> a warning is issued about
the potential for inaccurate results. Set <code>warn</code> to <code>FALSE</code> to turn
this off.</dd></dl>

Arguments

Lookup time zones of lat/long pairs — tz_lookup_coords

<dl>

<dt>lat</dt>
<dd>numeric vector of latitudes</dd>


<dt>lon</dt>
<dd>numeric vector of longitudes the same length as <code>x</code></dd>


<dt>method</dt>
<dd>method by which to do the lookup. Either <code>"fast"</code> (default)
or <code>"accurate"</code>.</dd>


<dt>warn</dt>
<dd>By default, if <code>method = "fast"</code> a warning is issued about
the potential for inaccurate results. Set <code>warn</code> to <code>FALSE</code> to turn
this off.</dd>

</dl>

tz_lookup_coords: Lookup time zones of lat/long pairs

Description

Usage

Value

Arguments

Examples