Question

Imaging that I have an array of places, and each item include name, lat and long of that place. Now I want to group nearby items using a radius in miles for example.

How do I achieve this in PHP?

Answer 1

You need to have a second array to store data. And a duplicate of your array of places.

for each $place in $places_array do
   store $place in $store_array
   for each $place2 in $places2_array do
      if $place2 == $place
         continue
      else
         if compare_radius() == true
             store $place2 in $store_array
         end_if
      end_else
   end_for
   erase each new data in store from $places2_array  (Only if you do not want to replicate data)
end_for

Vars

• $store_array: new array with all places group by proximity. Its structure can be sthing like [0]->[place_1][place_2], [1]->[place_1], etc…
• $places_array: your array of data.
• $places2_array: a duplicate from $places_array.

I know this is not an efficient algorithm, but it does the job. If you have many data, maybe it is better to use another algorithm.