二元函数求导

发表于 分类于 阅读次数： 本文字数： 3.2k 阅读时长 ≈ 3 分钟

单纯的无聊做的，实际一丁点用都没有！

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
package cn.sgnxotsmicf.Demo;

//二元多项式求导
import java.util.ArrayList;
import java.util.Scanner;
public class test0005 {
    public static void main(String[] args) {
        ArrayList<Double> var  = new ArrayList<>();//变量系数
        ArrayList<Double> exp  = new ArrayList<>();//幂次幂次
        ArrayList<Double> varX1  = new ArrayList<>();//求x1时x2幂次
        ArrayList<Double> varX2  = new ArrayList<>();//求x2时x1幂次
        Scanner sc = new Scanner(System.in);
        x1_x2Judge(sc,var,exp,varX1,varX2);
        input(var,exp,varX1,varX2);
    }

    private static void x1_x2Judge(Scanner sc,ArrayList<Double> var,ArrayList<Double> exp,
                                   ArrayList<Double> varX1,ArrayList<Double> varX2) {
        int i =0;
        System.out.println("输入1对x1求导:");
        int instruct1 = sc.nextInt();
        System.out.println("请输入关于x"+instruct1+"的项数:");
        int number1 = sc.nextInt();
        int tempt =operation(sc,var,exp,i,number1,instruct1,varX1,varX2);
        System.out.println("输入2对x2求导:");
        int instruct2= sc.nextInt();
        System.out.println("请输入关于x"+instruct2+"的项数:");
        int number2 = sc.nextInt();
        operation(sc,var,exp,tempt,number2,instruct2,varX1,varX2);
    }
    private static int operation(Scanner sc,ArrayList<Double> var,ArrayList<Double> exp,int i,int number,int instruct,
                                 ArrayList<Double> varX1,ArrayList<Double> varX2){
        int tempt = 0;
        do {
            System.out.println("请输入第" + (tempt + 1) + "个变量系数:");
            var.add(sc.nextDouble());
            System.out.println("请输入第" + (tempt + 1) + "个变量幂次:");
            exp.add(sc.nextDouble());
            if (instruct == 1) {
                derivation_Operation(var, exp, i);
            }else if (instruct == 2){
                derivation_Operation(var,exp,i);
            }
            Judge(instruct,sc,varX1,varX2);
            i++;
            tempt++;
        } while (tempt < number);
        return i;
    }
    private static void Judge(int instruct,Scanner sc,ArrayList<Double> varX1,ArrayList<Double> varX2) {
        if (instruct==1){
            System.out.println("该x"+instruct+"项(有/无)x2项相乘？");
            varX1_X2_Operation(sc,varX1);
        }else if (instruct==2){
            System.out.println("该x"+instruct+"项(有/无)x1项相乘？");
            varX1_X2_Operation(sc,varX2);
        }
    }

    private static void varX1_X2_Operation(Scanner sc,ArrayList<Double> varX) {
        String answer = sc.next();
        if (answer.equals("有")){
            System.out.println("幂次为多少？");
            double x = sc.nextInt();
            varX.add(x);
        }else if (answer.equals("无")){
            varX.add(0.0);
        }
    }

    private static void input(ArrayList<Double> var, ArrayList<Double> exp, ArrayList<Double> varX1,ArrayList<Double> varX2) {
        System.out.println("变量系数:"+var.toString());
        System.out.println("变量幂次:"+exp.toString());
        System.out.println("求x1时x2幂次:"+varX1.toString());
        System.out.println("求x2时x1幂次:"+varX2.toString());
    }

    private static void derivation_Operation(ArrayList<Double> var,ArrayList<Double> exp,int i) {
        if (var.get(i)==0||exp.get(i)==0){
            var.set(i,0.0);
            exp.set(i,0.0);
        }else {
            var.set(i,var.get(i)*exp.get(i));
            exp.set(i,exp.get(i)-1);
        }
    }
}