shayanjm

; Haversine formula
; a = sin²(Δφ/2) + cos φ1 ⋅ cos φ2 ⋅ sin²(Δλ/2)
; c = 2 ⋅ atan2( √a, √(1−a) )
; d = R ⋅ c
; where φ is latitude, λ is longitude, R is earth’s radius (mean radius = 6,371km);

(defn haversine
  "Implementation of Haversine formula. Takes two sets of latitude/longitude pairs and returns the shortest great circle distance between them (in km)"
  [{lon1 :lng lat1 :lat} {lon2 :lng lat2 :lat}]
  (let [R 6378.137 ; Radius of Earth in km

shayanjm

; "Reverse haversine" to derive lat/long from start point, bearing (degrees clockwise from north), & distance (km)
; φ2 = asin( (sin φ1 ⋅ cos δ) + (cos φ1 ⋅ sin δ ⋅ cos θ) )
; λ2 = λ1 + atan2( sin θ ⋅ sin δ ⋅ cos φ1, cos δ − sin φ1 ⋅ sin φ2 )
; where φ is latitude, λ is longitude, θ is the bearing (clockwise from north), δ is the angular distance d/R; d being the distance travelled, R the earth’s radius

(defn reverse-haversine
  "Implementation of the reverse of Haversine formula. Takes one set of latitude/longitude as a start point, a bearing, and a distance, and returns the resultant lat/long pair."
  [{lon :lng lat :lat bearing :bearing distance :distance}]
  (let [R 6378.137 ; Radius of Earth in km
        lat1 (Math/toRadians lat)

shayanjm

(ns project.core
    (:require [cognitect.transit :as transit])
    (:use kafka-clj.client :reload)
    (:import [java.io ByteArrayInputStream ByteArrayOutputStream]))
  
;; Set up connector here

(let [data (ByteArrayOutputStream. 4096)
                   writer (transit/writer data :json)]
               (transit/write writer link-difference)