Neues Package: org.hwo.statistics

src/org/hwo/statistics/Statistics.java

@@ -0,0 +1,63 @@
+package org.hwo.statistics;
+
+public class Statistics {
+
+	Float[] values;		// Wertereihe
+
+	boolean	uKnown;
+	
+	Float	u;			// Arithmetisches Mittel
+	Float	s2;			// Korrigierte Stichprobenvarianz
+	Float	s;			// Standardabweichung
+	
+	
+	
+	public Statistics(Float[] values){
+		this.values = values;
+		uKnown = false;
+	}
+	
+	private void calcU(){
+		float avg = 0;
+		for (int i=0;i<this.values.length;i++){
+			avg += this.values[i];
+		}
+		this.u = avg / this.values.length;
+	}
+	
+	private void calcS2(){
+		if (u == null)
+			calcU();
+		
+		s2 = 0.0f;
+		for (int i=0;i<this.values.length;i++){
+			s2 += (float)Math.pow(this.values[i] - this.u, 2.0f);
+		}
+		s2 /= uKnown ? this.values.length : (this.values.length - 1);
+		s = (float)Math.sqrt(s2);
+	}
+	
+	public Float getU() {
+		if (u == null)
+			calcU();
+		return u;
+	}
+	public void setU(Float u) {
+		this.u = u;
+		this.uKnown = true;
+		
+		this.s2 = null;
+		this.s = null;
+	}
+	public Float getS2() {
+		if (s2 == null)
+			calcS2();
+		return s2;
+	}
+	public Float getS() {
+		if (s == null)
+			calcS2();
+		return s;
+	}
+	
+}