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Can you determine if a GPS location is inside a polygon?
I have a Shape File. I'd like to know if it is possible to determine if a geo-location is within a particular polygon. If so, can you explain how to do this?
How can we help you today?
Use the INPOLYGON function.
Hi Will,
Thank you. I see the function, but how does it work? Do you have an examples or advice?
Thanks.
I'm trying to use this function to determine whether or not an inspection took place within a 4-sided polygon. I can't seem to get the function to return true.
I am requiring the user to get the GPS location using the Location field. I am using the results from that field in the INPOLYGON function. Doesn't seem to want to work for me.
I noticed that the GPS location from the location field returns location in DMS format. I tried using the GEO-FORMAT function to convert the DMS lat/lon to Decimal Format (which it appears the INPOLYGON function uses). Still won't work. Any ideas?
Should the INPOLYGON function work both within the form itself and as a condition within a connector?
Thanks
After giving this some thought I have come up with another solution that doesn't require the use of the INPOLYGON function.
1. Use a "Location" field in the form that requires the user to record the GPS location where the inspection is being performed.
2. Create hidden fields for Latitude LAT((inspectionLocation)) and Longitude LON{{inspectionLocation}} to extract the latitude and longitude from the {{inspectionLocation}} field.
3. Use another hidden field to determine whether or not the inspection took place within a polygonal geofence by using the following IF statement:
IF((({{lat}} < 40) AND ({{lat}} > 36) AND ({{lon}} > -80) AND ({{lon}} < -76)), 'True', 'False')
There might be a more elegant way to do this using the INPOLYGON function......however this approach works.
Thank you, Will -- that's a good solution!