237 lines
6.6 KiB
Markdown
237 lines
6.6 KiB
Markdown
# Geolib
|
|
[](http://travis-ci.org/manuelbieh/Geolib)
|
|
|
|
A small library to provide some basic geo functions like distance calculation, conversion of decimal coordinates to sexagesimal and vice versa, etc.
|
|
|
|
[View demo](http://www.manuel-bieh.de/publikationen/scripts/geolib/demo.html)
|
|
|
|
<h2>Methods</h2>
|
|
|
|
<h3>geolib.getDistance(object start, object end[, int accuracy])</h3>
|
|
|
|
Calculates the distance between two geo coordinates
|
|
|
|
Takes 2 or 3. First 2 arguments must be an object with a latitude and a longitude property (e.g. {latitude: 52.518611, longitude: 13.408056}). Coordinates can be in sexagesimal or decimal format. 3rd argument is accuracy (in meters). So a calculated distance of 1248 meters with an accuracy of 100 is returned as 1200.
|
|
|
|
Return value is always an integer and represents the distance in meters.
|
|
|
|
<h4>Examples</h4>
|
|
|
|
<pre>geolib.getDistance(
|
|
{latitude: 51.5103, longitude: 7.49347},
|
|
{latitude: "51° 31' N", longitude: "7° 28' E"}
|
|
);
|
|
geolib.getDistance(
|
|
{latitude: 51.5103, longitude: 7.49347},
|
|
{latitude: "51° 31' N", longitude: "7° 28' E"}
|
|
);
|
|
|
|
// Working with W3C Geolocation API
|
|
navigator.geolocation.getCurrentPosition(
|
|
function(position) {
|
|
alert('You are ' + geolib.getDistance(position.coords, {
|
|
latitude: 51.525,
|
|
longitude: 7.4575
|
|
}) + ' meters away from 51.525, 7.4575');
|
|
},
|
|
function() {
|
|
alert('Position could not be determined.')
|
|
},
|
|
{
|
|
enableHighAccuracy: true
|
|
}
|
|
);
|
|
</pre>
|
|
|
|
<h3>geolib.getCenter(array coords)</h3>
|
|
|
|
Calculates the geographical center of all points in a collection of geo coordinates
|
|
|
|
Takes an object or array of coordinates and calculates the center of it.
|
|
|
|
Returns an object: `{"latitude": centerLat, "longitude": centerLng, "distance": diagonalDistance}`
|
|
|
|
<h4>Examples</h4>
|
|
|
|
<pre>var spots = {
|
|
"Brandenburg Gate, Berlin": {latitude: 52.516272, longitude: 13.377722},
|
|
"Dortmund U-Tower": {latitude: 51.515, longitude: 7.453619},
|
|
"London Eye": {latitude: 51.503333, longitude: -0.119722},
|
|
"Kremlin, Moscow": {latitude: 55.751667, longitude: 37.617778},
|
|
"Eiffel Tower, Paris": {latitude: 48.8583, longitude: 2.2945},
|
|
"Riksdag building, Stockholm": {latitude: 59.3275, longitude: 18.0675},
|
|
"Royal Palace, Oslo": {latitude: 59.916911, longitude: 10.727567}
|
|
}
|
|
|
|
geolib.getCenter(spots);
|
|
geolib.getCenter([
|
|
{latitude: 52.516272, longitude: 13.377722},
|
|
{latitude: 51.515, longitude: 7.453619},
|
|
{latitude: 51.503333, longitude: -0.119722}
|
|
]);
|
|
</pre>
|
|
|
|
<h3>geolib.isPointInside(object latlng, array coords)</h3>
|
|
|
|
Checks whether a point is inside of a polygon or not.
|
|
Note: the polygon coords must be in correct order!
|
|
|
|
Returns true or false
|
|
|
|
<h4>Example</h4>
|
|
|
|
<pre>
|
|
geolib.isPointInside(
|
|
{latitude: 51.5125, longitude: 7.485},
|
|
[
|
|
{latitude: 51.50, longitude: 7.40},
|
|
{latitude: 51.555, longitude: 7.40},
|
|
{latitude: 51.555, longitude: 7.625},
|
|
{latitude: 51.5125, longitude: 7.625}
|
|
]
|
|
); // -> true</pre>
|
|
|
|
<h3>geolib.isPointInCircle(object latlng, object center, integer radius)</h3>
|
|
|
|
Similar to is point inside: checks whether a point is inside of a circle or not.
|
|
|
|
Returns true or false
|
|
|
|
<h4>Example</h4>
|
|
|
|
<pre>// checks if 51.525, 7.4575 is within a radius of 5km from 51.5175, 7.4678
|
|
geolib.isPointInCircle(
|
|
{latitude: 51.525, longitude: 7.4575},
|
|
{latitude: 51.5175, longitude: 7.4678},
|
|
5000
|
|
);</pre>
|
|
|
|
<h3>geolib.orderByDistance(object latlng, mixed coords)</h3>
|
|
|
|
Sorts an object or array of coords by distance from a reference coordinate
|
|
|
|
Returns a sorted array [{latitude: x, longitude: y, distance: z, key: property}]
|
|
|
|
<h4>Examples</h4>
|
|
|
|
<pre>
|
|
// coords array
|
|
geolib.orderByDistance({latitude: 51.515, longitude: 7.453619}, [
|
|
{latitude: 52.516272, longitude: 13.377722},
|
|
{latitude: 51.518, longitude: 7.45425},
|
|
{latitude: 51.503333, longitude: -0.119722}
|
|
]);
|
|
|
|
// coords object
|
|
geolib.orderByDistance({latitude: 51.515, longitude: 7.453619}, {
|
|
a: {latitude: 52.516272, longitude: 13.377722},
|
|
b: {latitude: 51.518, longitude: 7.45425},
|
|
c: {latitude: 51.503333, longitude: -0.119722}
|
|
});
|
|
</pre>
|
|
|
|
<h3>geolib.findNearest(object latlng, mixed coords[, int offset])</h3>
|
|
|
|
Finds the nearest coordinate to a reference coordinate.
|
|
|
|
<h4>Examples</h4>
|
|
|
|
<pre>var spots = {
|
|
"Brandenburg Gate, Berlin": {latitude: 52.516272, longitude: 13.377722},
|
|
"Dortmund U-Tower": {latitude: 51.515, longitude: 7.453619},
|
|
"London Eye": {latitude: 51.503333, longitude: -0.119722},
|
|
"Kremlin, Moscow": {latitude: 55.751667, longitude: 37.617778},
|
|
"Eiffel Tower, Paris": {latitude: 48.8583, longitude: 2.2945},
|
|
"Riksdag building, Stockholm": {latitude: 59.3275, longitude: 18.0675},
|
|
"Royal Palace, Oslo": {latitude: 59.916911, longitude: 10.727567}
|
|
}
|
|
|
|
// in this case set offset to 1 otherwise the nearest point will always be your reference point
|
|
geolib.findNearest(spots['Dortmund U-Tower'], spots, 1)
|
|
</pre>
|
|
|
|
<h3>geolib.getPathLength(mixed coords)</h3>
|
|
|
|
Calculates the length of a collection of coordinates
|
|
|
|
Returns the length of the path in kilometers
|
|
|
|
<h4>Example</h4>
|
|
|
|
<pre>
|
|
// Calculate distance from Berlin via Dortmund to London
|
|
geolib.getPathLength([
|
|
{latitude: 52.516272, longitude: 13.377722}, // Berlin
|
|
{latitude: 51.515, longitude: 7.453619}, // Dortmund
|
|
{latitude: 51.503333, longitude: -0.119722} // London
|
|
]); // -> 945235</pre>
|
|
|
|
|
|
<h3>geolib.getSpeed(coords, coords[, options])</h3>
|
|
|
|
Calculates the speed between to points within a given time span.
|
|
|
|
Returns the speed in <em>options.unit</em> (default is km/h).
|
|
|
|
<h4>Example</h4>
|
|
|
|
<pre>
|
|
geolib.getSpeed(
|
|
{lat: 51.567294, lng: 7.38896, time: 1360231200880},
|
|
{lat: 52.54944, lng: 13.468509, time: 1360245600880},
|
|
{unit: 'mph'}
|
|
); // -> 66.9408 (mph)</pre>
|
|
|
|
|
|
|
|
<h3>geolib.convertUnit(string unit, float distance[, int round])</h3>
|
|
|
|
Converts a given distance (in meters) to another unit.
|
|
|
|
<h4>Parameters</h4>
|
|
|
|
`unit` can be one of:
|
|
|
|
- m (meter)
|
|
- km (kilometers)
|
|
- cm (centimeters)
|
|
- mm (millimeters)
|
|
- mi (miles)
|
|
- sm (seamiles)
|
|
- ft (foot)
|
|
- in (inch)
|
|
- yd (yards)
|
|
|
|
`distance` distance to be converted (source must be in meter)
|
|
|
|
`round` fractional digits
|
|
|
|
<h4>Example</h4>
|
|
|
|
`geolib.convertUnit('km', 14213, 2) // -> 14,21`
|
|
|
|
<h3>geolib.sexagesimal2decimal(string coord)</h3>
|
|
|
|
Converts a sexagesimal coordinate to decimal format
|
|
|
|
<h4>Example</h4>
|
|
|
|
`geolib.sexagesimal2decimal("51° 29' 46\" N")`
|
|
|
|
<h3>geolib.decimal2sexagesimal(float coord)</h3>
|
|
|
|
Converts a decimal coordinate to sexagesimal format
|
|
|
|
|
|
<h4>Example</h4>
|
|
|
|
`geolib.decimal2sexagesimal(51.49611111); // -> 51° 29' 46.00`
|
|
|
|
|
|
<h3>geolib.useDecimal(mixed coordinate)</h3>
|
|
|
|
Checks if a coordinate is already in decimal format and, if not, converts it to
|
|
|
|
<h4>Example</h4>
|
|
<pre>geolib.useDecimal("51° 29' 46\" N"); // -> 51.59611111
|
|
geolib.useDecimal(51.59611111) // -> 51.59611111</pre>
|