80 lines
2.4 KiB
Java
80 lines
2.4 KiB
Java
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/*This is a Java Program to find the area of a polygon using slicker method. The algorithm assumes the usual mathematical convention that positive y points upwards. In computer systems where positive y is downwards (most of them) the easiest thing to do is list the vertices counter-clockwise using the “positive y down” coordinates. The two effects then cancel out to produce a positive area.*/
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//This is a java program to find the area of polygon using Slicker algorithm
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import java.util.*;
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class Area_polygon_Slicker
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{
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static final int MAXPOLY = 200;
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static final double EPSILON = 0.000001;
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static class Point
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{
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double x, y;
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}
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static class Polygon
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{
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Point p[] = new Point[MAXPOLY];
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int n;
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Polygon()
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{
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for (int i = 0; i < MAXPOLY; i++)
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p[i] = new Point();
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}
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}
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static double area(Polygon p)
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{
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double total = 0;
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for (int i = 0; i < p.n; i++)
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{
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int j = (i + 1) % p.n;
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total += (p.p[i].x * p.p[j].y) - (p.p[j].x * p.p[i].y);
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}
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return total / 2;
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}
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static public void main(String[] args)
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{
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Polygon p = new Polygon();
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Scanner sc = new Scanner(System.in);
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System.out.println("Enter the number of points in Polygon: ");
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p.n = sc.nextInt();
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System.out.println("Enter the coordinates of each point: <x> <y>");
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for (int i = 0; i < p.n; i++)
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{
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p.p[i].x = sc.nextDouble();
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p.p[i].y = sc.nextDouble();
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}
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double area = area(p);
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if (area > 0)
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System.out.print("The Area of Polygon with " + p.n
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+ " points using Slicker Algorithm is : " + area);
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else
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System.out.print("The Area of Polygon with " + p.n
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+ " points using Slicker Algorithm is : " + (area * -1));
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sc.close();
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}
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}
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/*
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Enter the number of points in Polygon:
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4
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Enter the coordinates of each point: <x> <y>
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1 1
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1 6
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6 6
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6 1
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The Area of Polygon with 4 points using Slicker Algorithm is : 25.0
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Enter the number of points in Polygon:
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5
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Enter the coordinates of each point: <x> <y>
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1 2
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4 5
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9 8
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3 2
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1 5
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The Area of Polygon with 5points using Slicker Algorithm is : 6.0
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