GlobalRayFactor_main.java

import java.util.HashMap;

public class GlobalRayFactor_main {
	/**
	 * HashMap with all ray factors. Key is a combination of beta and gamma.
	 * Example: 20°,0°=>20 + 0 = 20 | 45°,30°=>45 + 1 = 46 | 90°,45°=>90 + 2 = 92
	 */
	static HashMap<Integer, int[]> globalRayFacotrs;
	
	public static void main(String[] args) {
		System.out.println(globalRayFactor(0, 32, 16)); //expected 31
		System.out.println(globalRayFactor(0, 65, 45)); //expected 62
		System.out.println(globalRayFactor(0, 90, 38)); //expected 92
	}

	/**
	 * Searches global ray factor in hash map for the given parameters.
	 * 
	 * @param month int from 0 - 11
	 * @param beta float angle from 0° - 90°
	 * @param gamma float angle from -45° - 45°
	 * @return float global ray factor
	 */
	public static float globalRayFactor(int month, float beta, float gamma) {
		//calculate betaHash 
		int betaHash;
		if (beta < 25) {
			betaHash = 20;
		} else if (beta < 37.5) {
			betaHash = 30;
		} else if (beta < 52.5) {
			betaHash = 45;
		} else if (beta < 75) {
			betaHash = 60;
		} else {
			betaHash = 90;
		}
		
		//calculate gammaHash
		float gammaAbs = Math.abs(gamma);
		
		//rounds value to 0, 15, 30, 45
		int roundedGamma = 15 * Math.round(gammaAbs/15);
		
		//creates values 0, 1, 2, 3
		int gammaHash = roundedGamma/15;
		//creates values 0, 1, 2
		if (gammaHash > 1) gammaHash -= 1;
		
		int hashKey = betaHash + gammaHash;
		
		return hashKey;
		//@beni korrekter output mit gefüllter map
		//return globalRayFacotrs.get(hashKey)[month];
	}
}