Hi,
How to plot multiple marker using list in map.
Individually list contain one for latitude and longitude.
Please guide.
The National Parks tutorial) demonstrates how to plot multiple run time markers using a csv file to an OpenStreetMap. Use the list from csv Block to convert the csv to a List. What you do depends on how you make your List, where it is stored or is downloaded from.
What have you tried so far?
Regards,
Steve
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actually i convert spreadsheet data in json and imported the json data in appinventor.In appinventor i converted the JSON data into list and tried to plot multiple marker from list
You might then also be interested in Use a Google Spreadsheet hosted on your Google Drive to
update a Map .
Good luck with your Project.
Actually I am able to got the data from spreadsheet.Getting data from spreadsheet is not a issue.
I had a column of longitude and latitude in spreadsheet.That lat. and long. I want to plot as marker or circle in map with the help of appinventor using Map component.
Problem facing plotting multiple geo location as marker in map
@SteveJG thanks for replying me…now I am able to plot my spreadsheet multiple geodata in map with map.
Thanks.
Now I am looking for plot multiple circle with same Geo data.
Please share any idea…
Sorry Akash, it is only possible to use run time Markers. Developers cannot yet create run time circles Circle , Circle does not have a method similar to CreateMarker( latitude , longitude ) that Creates a new Circle on the Map at the specified latitude and longitude .
What can be done is
- tuse design time circles and turn on or off their visibility as needed (You require one circle for each location you intend to display)
- create a Custom Marker that is a circle.png or circle.svg image and use it instead of the stock Marker icons. ImageAssetSpecifies the image shown for the
Marker. See this for a way to set CustomMarkers
Does this help?
Regards,
Steve
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Thanks @SteveJG I will try and nice idea to show circle.impressive idea.
One more question…
Actually I am working for Geo fence…I want to check the minimum distance and alarm/alert the user from existing marker and current location of user.
Any ideas…
-
calculate the distance between the user location and an existing marker. Use the Marker DistanceToPoint
Or use a Block GreatCircle Algorithm
The Procedure calculates distance in miles. To calculate Great Circle distance in km, substitute the value for the earth’s radius (6371 km for 3951 mi shown in the image.).
-
use a geofence a circular geofence
-
use a rectangular geofence … Chapter 18. Programming Your App to Make Decisions showing example blocks that can be used to determine the geofence boundaries.
Be aware, it makes little sense to make the rectangle too small . The LocationSensor property of Accuracy shows that the reliability of the provided GPS sensor coordinates provided varies depending on many factors … read about it here --> Using the Location Sensor Read about the distance represented by 0.00001 deg latitude and search for several Forum topics that describe how to use the geofence.
Good luck. 
When you are done, consider sharing your code with the community and let us know what works for you.
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I am not getting actual distance between two lat-long.
I also used Haversine formula but still same problem.
Hi Akash,
-
I am not getting actual distance between two lat-long. Probably because you are not coding correctly. How do we know what you coded? The method you use may be calculating the straight-line distance between two locations, not how you would drive there and it might be calculating in meters or miles. We don’t know what you are doing.
-
You used Haversine and ‘same problem’. What Haversine algorithm and how did you implement it?
-
to calculate driving distance following a route if you don’t want a straight-line distance between points; try
- HOW TO: Use the Navigate control
- Use the Google Directions api. Use it with a Google Map API key .
– Steve
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