Jakarta-Common-Math使用笔记
时间:2011-01-28 csdn博客 沈斌
apache的math组件，尽管不常用，我今天也整理出来。
下载地址： http://commons.apache.org/math/
示例代码：
package demo;
import org.apache.commons.math.stat.descriptive.moment.GeometricMean;
import org.apache.commons.math.stat.descriptive.moment.Kurtosis;
import org.apache.commons.math.stat.descriptive.moment.Mean;
import org.apache.commons.math.stat.descriptive.moment.Skewness;
import org.apache.commons.math.stat.descriptive.moment.StandardDeviation;
import org.apache.commons.math.stat.descriptive.moment.Variance;
import org.apache.commons.math.stat.descriptive.rank.Max;
import org.apache.commons.math.stat.descriptive.rank.Min;
import org.apache.commons.math.stat.descriptive.rank.Percentile;
import org.apache.commons.math.stat.descriptive.summary.Product;
import org.apache.commons.math.stat.descriptive.summary.Sum;
import org.apache.commons.math.stat.descriptive.summary.SumOfSquares;
public class TestMathUserage ...{
public static void main(String[] args) ...{
double[] values = new double[] ...{ 0.33, 1.33, 0.27333, 0.3, 0.501,
0.444, 0.44, 0.34496, 0.33, 0.3, 0.292, 0.667 };
/**//*
* System.out.println( "min: " + StatUtils.min( values ) );
* System.out.println( "max: " + StatUtils.max( values ) );
* System.out.println( "mean: " + StatUtils.mean( values ) ); // Returns
* the arithmetic mean of the entries in the input array, or Double.NaN
* if the array is empty System.out.println( "product: " +
* StatUtils.product( values ) ); //Returns the product of the entries
* in the input array, or Double.NaN if the array is empty.
* System.out.println( "sum: " + StatUtils.sum( values ) ); //Returns
* the sum of the values in the input array, or Double.NaN if the array
* is empty. System.out.println( "variance: " + StatUtils.variance(
* values ) ); // Returns the variance of the entries in the input
* array, or Double.NaN if the array is empty.
*/
Min min = new Min();
Max max = new Max();
Mean mean = new Mean(); // 算术平均值
Product product = new Product();
Sum sum = new Sum();
Variance variance = new Variance();
System.out.println("min: " + min.evaluate(values));
System.out.println("max: " + max.evaluate(values));
System.out.println("mean: " + mean.evaluate(values));
System.out.println("product: " + product.evaluate(values));
System.out.println("sum: " + sum.evaluate(values));
System.out.println("variance: " + variance.evaluate(values));
Percentile percentile = new Percentile(); // 百分位数
GeometricMean geoMean = new GeometricMean(); // 几何平均数,n个正数的连乘积的n次算术根叫做这n个数的
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