topic Specify a number of map points within a certain distance in DAX Commands and Tips

Specify a number of map points within a certain distance

Anonymous — Fri, 07 Aug 2020 22:51:22 GMT

I am working with Longitude-Latitude values using the default powerBi map visualization. I want to be able to specify a certain distance and also be able to specify how many map points will be displayed within that radius. For example I would like maps to plot 500 or less lat-long points within any 1 mile radius in the US. Just to be clear, maps should plot all map points within the US that are quantity 500 or less in any 1 mile radius.
Can anyone help me to solve this in PowerBi or is there any other visualization tool in powerBi that can help me to do this?

Re: Specify a number of map points within a certain distance

lbendlin — Sun, 09 Aug 2020 01:04:35 GMT

Within a radius of what? What's in the center of your circle? Are you concerned about the curvature of the earth and/or the lat/lon grid size differences across the globe (which would require Euclidian math), or is this limited to a very small area where you can get away with assuming a rectangular grid?

Obligatory Flat Earther joke: "Our Flat Earth Society has members all over the globe!"

Another note: "As the crow flies" distance between two points is mostly meaningless in the real world. What you are likely looking for is driving time/route distance.

Re: Specify a number of map points within a certain distance

Anonymous — Mon, 10 Aug 2020 18:58:51 GMT

Thanks for your response Ibendlin.

Within any radius/distance which can be a filter to allow user to specify.

I am not necessarily concerned about the curvature of the earth.

So this is exactly my situation; I have ploted over a 500,000 lat-long points all across the united states and I wan't maps to show me where the points are mostly clustered or concentrated at within a small area (rectangular or otherwise, eg within any 50meters radius).

Re: Specify a number of map points within a certain distance

lbendlin — Mon, 10 Aug 2020 19:05:55 GMT

if you want to look "all across the united states" then you will want to consider the curvature of the earth, and the difference in longitude width depending on latitude. It is too large of an area to work with approximations. 50 meters have a different longitude span in Florida than they have in Alaska, by a lot.