Filter by Point in Polygon and Return County Name

[Zac Rinehart]

Hey I'm using topojson to create a map, I also have user inputs for lat/long. With this, I'd like to create a function that returns the FIPS id of the county when the user clicks search. I tried two approaches:

First:

var containing_county = us.objects.counties.geometries.filter(function(polygon) {
       return d3.polygonContains(polygon, [long.value, lat.value]);
   });
   console.log(containing_county)
 });

And then:

   var containing_county = topojson.feature(us, us.objects.counties).features.filter(function(d) { 
return d3.polygonContains(d.geometry, [long.value, lat.value]);
   console.log(containing_county)
    });

What should this filter look like? 

Minimalist block here (might have to full screen it to see inputs):

https://bl.ocks.org/diggetybo/6d35e5ecd17992650d0a23896e649b25

[sandeep edara]

Hi Zac,

Have created a block with a solution,

Tested using following lat : 39.99 and long : -109.99

https://bl.ocks.org/sandeepedara/raw/3d3e9fe7d3a3be8707e931276ed86326/

Regards,

Sandeep.

[Zac Rinehart]

Wow, great work. I'm looking over it now to see how you did it. Thanks so much!