13 KiB
SEARCH
, or Looking for Places
Geocoding is the process of matching an address to its corresponding geographic coordinates. There's nothing inherent in the words "10 Downing Street, London, United Kingdom" that conveys its location at the coordinates [ 51.503396, -0.12764 ]
. Instead this process [...].
π« π π¦ πΊπΈ π‘ π₯ ......... π»
The most basic scenario
You just set the text
parameter to whatever you want to find.
Let's say you wanted to find Stinky Beach
You would set the following parameters in your query url:
parameter | value |
---|---|
text |
stinky beach |
api_key |
get yours here |
[/v1/search?api_key={YOUR-KEY}&text=stinky beach](https://search.mapzen.com/v1/search?api_key={YOUR_API_KEY}&text=stinky beach)
...go ahead, and click that link, we'll wait
Maybe you'd like to find an address
Here's an example:
parameter | value |
---|---|
text |
30 west 26th street |
api_key |
get yours here |
[/v1/search?api_key={YOUR-KEY}&text=30 west 26th street](https://search.mapzen.com/v1/search?api_key={YOUR_API_KEY}&text=30 west 26th street)
Or maybe a landmark, like Yankee Stadium
parameter | value |
---|---|
text |
yankee stadium |
api_key |
get yours here |
[/v1/search?api_key={YOUR-KEY}&text=yankee stadium](https://search.mapzen.com/v1/search?api_key={YOUR_API_KEY}&text=yankee stadium)
cApiTaliZAtioN
You may have noticed already that cApiTaliZAtioN isn't a big deal for search. You can type yankee stadium or Yankee Stadium or even YANKEE STADIUM if you're really excited about finding it. See for yourself by comparing the results of the previous search to the following:
parameter | value |
---|---|
text |
YANKEE STADIUM |
api_key |
get yours here |
[/v1/search?api_key={YOUR-KEY}&text=YANKEE STADIUM](https://search.mapzen.com/v1/search?api_key={YOUR_API_KEY}&text=YANKEE STADIUM)
Results
Now that you've seen some examples of search, let's examine the results closer.
When requesting search results you will always get back GeoJSON
results, unless something goes terribly wrong, in which case you'll get a really helpful error.
You can go here to learn more about the
GeoJSON
data format specification. We'll assume you're familiar with the general layout and only point out some important details here.
You will find the following top-level structure to every response:
{
"geocoding":{...},
"type":"FeatureCollection",
"features":[...],
"bbox":[...]
}
For the purposes of getting started quickly, let's keep our focus on the features property of the result. This is where you will find the list of results that best matched your input parameters.
Each item in this list will contain all the information needed to identify it in human-readable format in the properties
block, as well as computer friendly coordinates in the geometry
property. Note the label
property, which is a human-friendly representation of the place, ready to be displayed to an end-user.
{
"type":"Feature",
"properties":{
"gid":"...",
"layer":"address",
"source":"osm",
"name":"30 West 26th Street",
"housenumber":"30",
"street":"West 26th Street",
"postalcode":"10010",
"country_a":"USA",
"country":"United States",
"region":"New York",
"region_a":"NY",
"county":"New York County",
"localadmin":"Manhattan",
"locality":"New York",
"neighbourhood":"Flatiron District",
"confidence":0.9624939994613662,
"label":"30 West 26th Street, Manhattan, NY"
},
"geometry":{
"type":"Point",
"coordinates":[
-73.990342,
40.744243
]
}
}
There is so much more to tell you about the plethora of data being returned for each search, we had to split it out into its own section. Read more about the response format.
Result count
You may have noticed that there were 10 places in the results for all the previous search examples. That's the default number of results the API will return, unless otherwise specified.
Want a single result?
Just set the size
parameter to the desired number:
parameter | value |
---|---|
text |
stinky beach |
size |
1 |
api_key |
get yours here |
[/v1/search?api_key={YOUR-KEY}&text=stinky beach&size=1](https://pelias.bigdev.mapzen.com/v1/search?api_key={YOUR_API_KEY}&text=stinky beach&size=1)
How about 25 results?
parameter | value |
---|---|
text |
stinky beach |
size |
25 |
api_key |
get yours here |
[/v1/search?api_key={YOUR-KEY}&text=stinky beach&size=25](https://pelias.bigdev.mapzen.com/v1/search?api_key={YOUR_API_KEY}&text=stinky beach&size=25)
Narrowing your Search
All this time you've been searching the entire world...
What if you need results from only a...
Sometimes it's necessary to limit the search to a portion of the world. This can be useful if you're looking for places in a particular region, or country, or only want to look in the immediate viscinity of a user with a known location. Different usecases call for different specifications of this bounding region. We currently support three types: rectangle, circle, and country.
...rectangular region
In the case where you need to specify the boundary using a rectangle, all we need is a pair of coordinates on earth. Here are a few examples:
Let's say you wanted to find museums in London
You'd need to set the boundary.rect.*
parameter grouping to indicate the extent of the boundary.
parameter | value |
---|---|
text |
museum |
boundary.rect.min_lat |
51.286839 |
boundary.rect.min_lon |
-0.51035 |
boundary.rect.max_lat |
51.692322 |
boundary.rect.max_lon |
0.33403 |
api_key |
get yours here |
Below is the region that will be searched. Museums located outside of this highlighted region will NOT be included in the results. The museums returned will be sorted based on how well they matched the text
parameter, in this case museum.
Or you wanted to find an address, such as 28 Main Ave, in New York City?
parameter | value |
---|---|
text |
28 Main Ave |
boundary.rect.min_lat |
51.286839 |
boundary.rect.min_lon |
-74.258904 |
boundary.rect.max_lat |
40.477421 |
boundary.rect.max_lon |
-73.700378 |
api_key |
get yours here |
[/v1/search?api_key={YOUR-KEY}&text=28 Main Ave&boundary.rect.min_lat=51.286839&boundary.rect.min_lon=-74.258904&boundary.rect.max_lat=40.477421&boundary.rect.max_lon=-73.700378](http://pelias.bigdev.mapzen.com/v1/search?api_key={YOUR_API_KEY}&text=28 Main Ave&boundary.rect.min_lat=51.286839&boundary.rect.min_lon=-74.258904&boundary.rect.max_lat=40.477421&boundary.rect.max_lon=-73.700378)
...circular region
Sometimes you don't have a rectangle to work with, but you you've got instead a point on earth, for example your location coordinates, and a maximum distance within which acceptable results can be located.
Find all Starbucks locations within a 3km radius of a spot in Madrid
This time, we'll use the boundary.circle.*
parameter grouping to get the job done. boundary.circle.lat
and boundary.circle.lon
should be set to your location in Madrid, while boundary.circle.radius
should be set to the acceptable distance from that location. Note that the boundary.circle.radius
parameter is always specified in kilometers.
parameter | value |
---|---|
text |
starbucks |
boundary.circle.lat |
40.414149 |
boundary.circle.lon |
-3.703755 |
boundary.circle.radius |
3 |
api_key |
get yours here |
...specific country
Sometimes your usecase might require that all the search results are from a particular country. Well, we've got that covered! You just need to set the boundary.country
parameter value to the alpha-2 or alpha-3 ISO-3166 country code.
Try searching for San Francisco in Columbia
parameter | value |
---|---|
text |
san francisco |
boundary.country |
COL |
api_key |
get yours here |
[/v1/search?api_key={YOUR-KEY}&text=san francisco&boundary.country=COL](http://pelias.bigdev.mapzen.com/v1/search?api_key={YOUR_API_KEY}&text=san francisco&boundary.country=COL)
Note that all the results have country
set to Columbia.
Now try searching for San Francisco in the USA
parameter | value |
---|---|
text |
san francisco |
boundary.country |
US |
api_key |
get yours here |
[/v1/search?api_key={YOUR-KEY}&text=san francisco&boundary.country=US](http://pelias.bigdev.mapzen.com/v1/search?api_key={YOUR_API_KEY}&text=san francisco&boundary.country=US)
You can see all the results are now from within the US, and the top place is San Francisco, CA. Awesome, right?!
Boundary issues
If you're going to attempt using multiple boundary types in a single search request, be aware that the results will come from the intersection of all the boundaries! So if you provide regions that don't overlap, you'll be looking at an empty set of results. You've been warned. Here's a visual of how it works:
Prioritizing Nearby Places
Many usecases call for the ability to surface nearby results to the front of the list, while still allow important matches from further away to be visible. If that's your conundrum, here's what you've got to do.
Focus on a point
Search will focus on a given point anywhere on earth, and results within ~50km will be prioritized. Once all the nearby results have been found, additional results will come from the rest of the world.
- focus viewport api example (e.g. union square)
- focus point api example (NY union square)
TBD
Combining Focused Results with Boundaries
-
Focus within country example
-
Focus within large bounding box example (e.g. maximum distance a user is willing to travel)
Selecting Datasets
Mapzen search offers two types of options for selecting the dataset you want back:
- the originating source of the data (
sources
) - the kind of place you're looking to geocode against (
layers
)
Selecting Sources
{list sources, not different licenses} {combine source listing, e.g. open addresses + Geonames}
Selecting Layers
Layer Name | Represents |
---|---|
venue |
Points of interest, businesses, things with walls |
address |
Places with a street address |
country |
Places that issue passports, nations, nation-states |
region |
States and provinces |
county |
Official governmental area; usually bigger than a locality, almost always smaller than a region |
locality |
Towns, hamlets, cities, etc. |
localadmin |
|
neighbourhood |
|
coarse |
Alias for simultaneously using country , region , county , locality , localadmin , and neighbourhood |
Our layers are derived from the hierarchy created by the gazetteer Who's on First and can be used to facilitate coarse geocoding.
Coarse Geocoding (Neighborhoods, Cities, States, Countries)
There are many cases where you're after not a point, but a general area, whether it's the name of a town, a neighborhood, a county, or a country.
- Coarse general
- Select cities
- Select localities in a country (with boundary.country)
Using Autocomplete & Search Together
For end-user applications, /autocomplete
is intended to be used alongside /search
to facilitate real-time feedback for user s