To this topic I have found a very good and helpful entry:
Map View draw directions using google Directions API - decoding polylines
But I have a question to the answer of Kenny.
He has written a function called decodeZoomLevels(String encodedZoomLevels)
and what paramenter is the encodedZoomLevels?
As my direction API response I get a polyline entry like this:
.
.
.
"polyline" : {
"points" : "grheHevjqAo#i#WMm#]a#QUGoAKqAG{#Ea#Ge#E]Im#Wa#Ou#Uy#MEI]OAICGEECAGAG#A#A?CBABAFc#HOJeB?}FNiBHaENw#Be#Bc#Ee#Gq#Wo#[w#i#[c#c#q#mAgC_#u#e#{#aA{Ai#k#u#w#c#g#w#gAiAqBMUEIaCsEmBuDqBqEkAyB{#gASWs#s#aBcBc#o#g#{#_#w#c#m#USWOg#O_#E}AGS?UA[COCe#O}#s#q#kA[aAUuASmAS}#So#IOQYc#s#w#u#u#Y"
},
.
.
.
As you can see the polyline entry has only another entry called "points", but wehere is the entry "zoomlevel" as Kenny is describing?
Hope you can help.
Zoom levels is the array of integers, where each number control the appearance of points in different zoom levels. In other words, if it is present, it can reduce number of points visible in lower zoom levels, but allowing to show more details when zooming in. It is not generated automatically, and I suppose to generate such a feature you need to implement polygon reducing algorithm.
Do you really need it?
Read more in google's manual.
Related
I'm making an app with Xamarin.Forms.Maps and then, I need to get all of the steps between two "place id" to make my own polyline. However, when I'm making my request, I get about only thirty five steps.
35 steps.. Between Le Mans (France) and Paris (France).. About 200km but only 35 steps.. The problem isn't that the two points aren't connected to the polyline made, no, the problem is that the polyline get out of the existing road..
Google API direction seems to give me, only, some important information, like important steps, but without following the road.. Does it normal?
PS: This is my request (I use Postman to test it)
https://maps.googleapis.com/maps/api/directions/json?origin=Le Mans&destination=Paris&key=[MY_API_KEY]&travel_mode=DRIVING
Are you using the polyline results in each driving step?
I used your example and got 31 start_location that each contain Encoded Polylines for drawing that path on the map.
The "Take the exit toward Paris-Centre Porte de Bercy" step results in:
"polyline": {
"points": "mn_iHmxqM#[?WA_#Ck#CeAAMGcAEi#Gc#Ke#GUI[IYGSIMIKGECAMIMEA?EAA?A?K?I#A?C?IBE#C#?#C#GBOHEHGJIVIX_#j#"
},
Decoded that is:
The "Take the exit on the left onto Bd Périphérique" step results in 91 points, etc...
There are hundreds and hundreds of locations points within the results, you just have to decode the locations of each driving step and plot them:
Google's Interactive Poly Line Utility
I have a mapbox, and want to display a layer of esri data onto it. The data I'm getting is being pulled in from this json file:
https://gis.usps.com/arcgis/rest/services/EDDM/selectZIP/GPServer/routes/execute?f=json&env%3AoutSR=102100&ZIP=93003&Rte_Box=R&UserName=EDDM
The data['results'][0]['value']['features'] array looks something like this:
[{'attributes': {'key':'value'}},{'geometry':{'paths':[[-13273770,4064608],[-13273762,4064613],....]}},
{'attributes': {'key':'value'}},{'geometry':{'paths':[[-13273770,4064608],[-13273762,4064613],....]}},
{'attributes': {'key':'value'}},{'geometry':{'paths':[[-13273770,4064608],[-13273762,4064613],....]}}}]
My question is about the geometry array. The data there is not Lat/Lng values (which I was hoping for), so I'm not sure how to add these to my map. I'm new to GIS, and the research I've done so far points to SpatialReferences. Any help is obviously much appreciated!
MapBox seems to only accept Latitude and Longitude coordinates (from what I can tell at least). The coordinates you have in your file come from ESRI 102100 (3857) projection system - the clue is near the beginning of your file:
"spatialReference":{"wkid":102100,"latestWkid":3857}..."
Normally, you'd have to convert this yourself, a good link for potential tips in the future is:
https://gis.stackexchange.com/questions/9442/arcgis-coordinate-system
On this occasion however, you can do something far easier. Simply change the "outSR" property of your URL from 102100 to 4326 (WGS84) and let it do it for you.
https://gis.usps.com/arcgis/rest/services/EDDM/selectZIP/GPServer/routes/execute?f=json&env%3AoutSR=4326&ZIP=93003&Rte_Box=R&UserName=EDDM
I'm trying to create a corridor along a road. Therefore I need some kind of a coordinate set. Currently I'm requesting a route and using it's coordinates. But with this approach I run into problems if there is a long segment, eg. 200km on a highway. If I only use the position of the instructions when getting onto the highway and when exiting it, the corridor may miss some parts of the road since it may not be a straight one.
So what I'd like to do is, query the "major" road coordinates of a road. For now it does not matter if id needs an ID or the road name or any coordinates.
I'm currently working with HERE maps, but if there is any other service which may fulfill my requirement, I'm open to review and test it. I also reviewed google-maps api, but still not found a service or any similar approach.
Thanks in advance.
If I understand your question correctly you need to obtain the full geometry of the route first, then prune the result down to the coordinates you want.
For both the HERE 7.2 routing API and the 6.2 Enterprise Routing API, If you want to obtain the shape of a route you just need to include the parameter routeattributes=shape.
e.g.
.../calculateroute.json?waypoint0=lat,lng&waypoint1=lat,lng&mode=fastest:car:traffic:Adefault&routeattributes=shape&app_id=YOR_APPID&app_code=YOUR_TOKEN
The full geometry (of routes or manuevers) is not usually returned without the shape enum being set.
This is explained in the API User guide as shown:
routeAttributes
Define which atrributes are included in the response as part of the data representation of the route. Defaults to waypoints, summary,summaryByCountry legs, lines. See also RouteAttributeType.
Enum [waypoints | summary | summaryByCountry | shape | boundingBox | legs | notes ]
The route shape example within the API explorer returns :
[
"52.5160414,13.3782982",
"52.5163436,13.3782148",
"52.5162363,13.3783329",
"52.5162148,13.3786547",
"52.5162792,13.3795774",
"52.5163651,13.3808541",
"52.5165153,13.3807898",
"52.516644,13.3807361",
"52.5169337,13.3806503",
"52.5181997,13.3804357",
"52.5189185,13.380264",
"52.5189829,13.3811975",
"52.5191653,13.3820879",
"52.5197446,13.3840835",
"52.5201201,13.3851671",
"52.5203025,13.3855319",
"52.52056,13.3859825",
"52.5206485,13.3861105"
], ... etc.
within the response.
I'm trying to add WMS layer from remote ArcGIS server to my GWT web app. I'm using gwt-openlayers library.
My code:
MapOptions defaultMapOptions = new MapOptions();
mapWidget = new MapWidget("100%", "100%", defaultMapOptions);
Map map = mapWidget.getMap();
//gNormal = new GoogleV3("Google Normal", gOptions);
//map.addLayer(gNormal);
WMSParams wmsParams = new WMSParams();
wmsParams.setFormat("image/png");
wmsParams.setLayers("1");
wmsParams.setStyles("");
WMSOptions wmsLayerParams = new WMSOptions();
wmsLayerParams.setUntiled();
wmsLayerParams.setProjection("EPSG:3857"); // is it correct setting for WMS layer?
// wmsLayerParams.setProjection("EPSG:102113");
// wmsLayerParams.setProjection("EPSG:4326");
wmsLayerParams.setTransitionEffect(TransitionEffect.RESIZE);
String wmsUrl = "sampleserver1.arcgisonline.com/ArcGIS/services/Specialty/ESRI_StatesCitiesRivers_USA/MapServer/WMSServer";
arcGis = new WMS("ArcGis", wmsUrl, wmsParams);
map.addLayer(arcGis);
map.setBaseLayer(arcGis);
LonLat lonLat = new LonLat(-84.1,36.4); //USA
lonLat.transform("EPSG:4326", map.getProjection());
//System.out.println("map projection "+map.getProjection());
map.setCenter(lonLat, 3);
add(mapWidget);
I read many articles and SO questions but I still can't solve the problem. My problem is rendering pink tiles on the map instead of normal image. I copied image url as many stackoverflow answers suggested and saw the following:
http://localhost:8084/sampleserver1.arcgisonline.com/ArcGIS/services/Specialty/ESRI_StatesCitiesRivers_USA/MapServer/WMSServer?FORMAT=image%2Fpng&LAYERS=1&STYLES=&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&SRS=EPSG%3A4326&BBOX=-135,45,-90,90&WIDTH=256&HEIGHT=256
Without localhost:8084 prefix url works fine and shows me small piece of map.
Questions:
1) How get rid from localhost prefix in WMS url? In my code wmsUrl look like sampleserver1... so it's correct. It seems my application adds it's root path to remote url.
2) I read that WMS layers should have the following projection - "EPSG:3857". Is it true? As i mentioned above when I manually put in the browser correct url without "localhost" prefix I saw some image but I'm not sure it's correct. Probably image is shifted.
3) My final goal is adding 2 layers to the map - Google Map layer and WMS layer. Google Map uses "EPSG:900913" as default projection. Could somebody give common tips to place google layer and WMS layer in one map. May be there are some tricks, common mistakes related to projections an so on.
In the wmsUrl variable, you are missing the "http://", that may help.
Pink tiles generally mean that the data source was not found, so this is where you should look for the problem. Try checking the wms URL you are supplying in a wms viewer (e.g. ArcGIS Explorer ).
To your questions:
1)try just adding the http:// to your url, without the localhost
2)A WMS layer can have any projection, it depends solely on the projection in which it was published. Information about a specific WMS's projection should be found in metadata.
3)If the two layers have the same projection, you do not need to do anything. If you want to use two layers in different projections in one map, one of the layers must be reprojected. In pure OpenLayers, this is done by specifying the projection parameter for each layer and then specifying the displayProjection parameter for the map. The layers will automatically be reprojected. However, reprojection takes some time and it increases the load time VERY significantly. It is better to avoid reprojection on-the-fly, if possible. You can either reproject the source data of one of the layers and use reprojected data. Of course, this is not possible for a WMS, so you should consider using a different data source. If you want a background map, you can donwload OpenStreetMap data, reproject them to your desired projection, and then use them with the other WMS you want to use.
Hope at least some of this helps :-)
Suppose I have a route defined from one town to another. From the Google Maps API I can recover a route between the two. However, the route returned from Google is a driving route that includes geo-coordinates only at places where there is another step in a leg (for example, where I have to turn from one highway to another).
What I need is geo-locations (lat/long) along the entire route, at specific intervals (for example, every 1/4 mile or 100m).
Is there a way to accomplish this via the Google Maps API / web services?
Or would the OpenStreetMap database be the way to do it?
Kind regards,
Madeleine.
OSRM gives you routes with road geometries as they are in the OpenStreetMap database. For example, you can get the route as GPX (and post-process this file if you want). This would look like the following:
GET http://router.project-osrm.org/viaroute?hl=en&loc=47.064970,15.458470&loc=47.071100,15.476760&output=gpx
Read more: OSRM API docs.
Since the accepted answer is outdated and does not work anymore, here is how all nodes along a road can be queried using the route service from Project OSRM.
Given an arbitrary number of lon,lat pairs.
For Instance the following three (in Berlin):
13.388860,52.517037
13.397634,52.529407
13.428555,52.523219
The route-service calculates the fastest route between these points and its possible to return all nodes along the road using the following query:
http://router.project-osrm.org/route/v1/driving/13.388860,52.517037;13.397634,52.529407;13.428555,52.523219?alternatives=false&annotations=nodes
This returns a json response containing node IDs of all the nodes along the route. The result should look something like this:
{
"routes": [
{
...
"legs": [
{
"annotation": {
"nodes": [
2264199819,
2045820592,
21487242,
...
]
}
To receive the lat,lon coordinates of the nodes OverpassAPI can be used.
[out:json];
(
node(264199819);
node(...);
node(...);
...
);
(._;>;);
out;
Here is a sample request using overpass-turbo: http://overpass-turbo.eu/s/toe
It's simply google.maps.DirectionsService().route() method. You need to pass the service request and then a callback which executes upon completion of the service request.
https://developers.google.com/maps/documentation/javascript/directions
While not used as API, here: https://www.nmeagen.org/ one can create "Multi-point line", set the distance between points and download route (coordinates) as CSV.
Adding to the Marlio's answer.
You can use Google Maps Directions API itself.
For a given origin and destination, in the JSON output, look for following:
"polyline" : {
"points" : ""
}
You can use a decoder to get the coordinates from the polyline.:
https://github.com/emcconville/google-map-polyline-encoding-tool
Or. you can use the googleway package in R to decode the same.
https://cran.r-project.org/web/packages/googleway/googleway.pdf
I am not sure how to set the resolution to your desired level though.But the resolution in the API output is really good.