我做了一个测试程序,通过Apache Commons Math库尝试NewtonRaphsonSolver类。牛顿法用于求给定函数的根。
我编写的测试程序引用了 cos(x) 函数(我有一个更难分析的函数,我首先查看 cos(x) 函数)。
测试程序的代码是
import org.apache.commons.math3.analysis.differentiation.DerivativeStructure;
import org.apache.commons.math3.analysis.differentiation.UnivariateDifferentiableFunction;
import org.apache.commons.math3.analysis.solvers.*;
import org.apache.commons.math3.exception.DimensionMismatchException;
public class Test3 {
public static void main(String args[]) {
NewtonRaphsonSolver test = new NewtonRaphsonSolver();
UnivariateDifferentiableFunction f = new UnivariateDifferentiableFunction() {
public double value(double x) {
return Math.cos(x);
}
@Override
public DerivativeStructure value(DerivativeStructure t) throws DimensionMismatchException {
return t.cos();
}
};
for (int i = 1; i <= 500; i++) {
System.out.println(test.solve(1000, f, i, i+0.1));
}
}
}
不确定我是否需要两次引用 Math.cos(x) 和 t.cos()
public double value(double x) {
return Math.cos(x);
}
@Override
public DerivativeStructure value(DerivativeStructure t) throws DimensionMismatchException {
return t.cos();
}
牛顿的方法找到所有的零并将它们显示给用户。
1.5707963267948966
1.5707963267948966
-7.853981633974483
4.71238898038469
4.71238898038469
1.5707963267948966
7.853981633974483
7.853981633974483
10.995574287564276
10.995574287564276
10.995574287564276
10.995574287564276
14.137166941154069
14.137166941154069
14.137166941154069
127.23450247038663
17.278759594743864
17.278759594743864
23.56194490192345
20.420352248333657
20.420352248333657
39.269908169872416
23.56194490192345
23.56194490192345
14.137166941154069
26.703537555513243
26.703537555513243
23.56194490192345
29.845130209103036
29.845130209103036
26.703537555513243
32.98672286269283
32.98672286269283
32.98672286269283
36.12831551628262
36.12831551628262
36.12831551628262
23.56194490192345
39.269908169872416
39.269908169872416
45.553093477052
42.411500823462205
42.411500823462205
有什么方法可以防止打印出重复的零吗?例如,上面的输出将显示为
1.5707963267948966
4.71238898038469
7.853981633974483
10.995574287564276
14.137166941154069
17.278759594743864
20.420352248333657
23.56194490192345
26.703537555513243
29.845130209103036
32.98672286269283
36.12831551628262
39.269908169872416
42.411500823462205
45.553093477052
这可以在 for 循环内或通过仅打印出不重复值的数组来完成吗?