Meteorological Data Analysis Using MapReduce

Algorithm 3

// map(key, value)

Input: key,value, Global variable centers, the offset key, the sample value

Output: key^′,value^′, where key′ is the index of the closet center point near the value′.

(1) Construct a global variable centers, then assign the center point to centers.

(2) minDistance = MAX_VALUE;

(3) For (𝑖=0; 𝑖<= centers.length; 𝑖++)

{

  If (distance(point, centers[𝑖]) < minDistance)

   minDistance = distance(point, centers[𝑖]);

   index = 𝑖}

(4) }

(5) Key′ = nearestCluster

(6) Output (key′, value′)

(7) End