C/C++教程

C++行列式操作

本文主要是介绍C++行列式操作,对大家解决编程问题具有一定的参考价值,需要的程序猿们随着小编来一起学习吧!
  1 #include <iostream>
  2 #include <fstream>
  3 using namespace std;
  4 
  5 class Det
  6 {
  7 public:
  8     void InitializeSize(int order);
  9     void Remove(void);
 10     void Transpose(void);
 11     void RowOperate(int objectrow, int targetrow, double times);
 12     void ColumnOperate(int objectcolumn, int targetcolumn, double times);
 13     void SetAValue(int row, int col, double value);
 14     void InitializeValues(FILE *_fp);
 15     double Calculate(void);
 16 //private:
 17     double **Matrix;
 18     int order;
 19 };//-row|column
 20 void Det::RowOperate(int objectrow, int targetrow, double times)
 21 {
 22     for (int i = 0; i<order; i++)
 23         Matrix[targetrow][i] += times*Matrix[objectrow][i];
 24 }
 25 void Det::ColumnOperate(int objectcolumn, int targetcolumn, double times)
 26 {
 27     for (int i = 0; i<order; i++)
 28         Matrix[targetcolumn][i] += times*Matrix[objectcolumn][i];
 29 }
 30 void Det::Transpose()
 31 {
 32     double temp;
 33     for (int i = 0; i<order; i++)
 34         for (int j = 0; j<i - 1; j++)
 35         {
 36             temp = Matrix[i][j];
 37             Matrix[i][j] = Matrix[j][i];
 38             Matrix[j][i] = temp;
 39         }
 40 }
 41 void Det::InitializeSize(int inorder)
 42 {
 43     order = inorder;
 44     Matrix = new double *[order];
 45     for (int i = 0; i<order; i++)
 46     {
 47         Matrix[i] = new double[order];
 48     }
 49 }
 50 void Det::Remove()
 51 {
 52     for (int i = 0; i<order; i++)
 53         delete[] Matrix[i];
 54     delete[] Matrix;
 55     order = 0;
 56     Matrix = NULL;
 57 }
 58 /*double Det::Calculate()//BUG HERE
 59 {
 60     for (int t = 1; t<order; t++)
 61         for (int o = 0; o<t; o++)
 62             Det::RowOperate(o, t, Matrix[t][o] / Matrix[o][o]);
 63     double ret = 1;
 64     for (int i = 0; i<order; i++)
 65         ret *= Matrix[i][i];
 66     printf("%lf", ret);
 67     return ret;
 68 }*/
 69 double Det::Calculate()//BUG HERE
 70 {
 71     //备份Matrix
 72     double temp[order*order];
 73     for (int i = 0; i<order; i++)
 74         for (int j = 0; j<order; j++)
 75             temp[i*order+j]=Matrix[i][j];
 76     //计算行列式
 77     for (int t = 1; t<order; t++)
 78         for (int o = 0; o<t; o++)
 79             {
 80                 double times = Matrix[t][o] / Matrix[o][o];
 81                 for (int i = 0; i < order; i++)
 82                 {
 83                     Matrix[t][i] -= times * Matrix[o][i];
 84                 }
 85             }
 86     //统计
 87     double ret = 1;
 88     for (int i = 0; i<order; i++)
 89         ret *= Matrix[i][i];
 90     
 91     //还原Matrix
 92     for (int i = 0; i<order; i++)
 93         for (int j = 0; j<order; j++)
 94             Matrix[i][j]=temp[i*order+j];
 95             
 96     return ret;
 97 }
 98 void Det::SetAValue(int row, int col, double value)
 99 {
100     Matrix[row][col] = value;
101 }
102 void Det::InitializeValues(FILE *_fp)
103 {
104     //不知道>>输入时如何去掉",",就用FILE*吧
105     /*ifstream fp;
106     fp.open(filename);
107     for(int i = 0; i<order; i++)
108     for(int j = 0; j<order; j++)
109     fp >> Matrix[i][j];
110     fp.close();*/
111     fseek(_fp, 0, SEEK_SET);
112     for (int i = 0; i<order; i++)
113         for (int j = 0; j<order; j++)
114             fscanf(_fp, "%lf,", &(Matrix[i][j]));
115 }
116 
117 
118 int main(int argc, char **argv)
119 {
120     if (2 != argc)
121     {
122         puts("Arguments Error!");
123         exit(-1);
124     }
125     /*ifstream fp;
126     char ch;    
127     int i = 0, n = 0;
128     fp.get(ch);
129     while (ch != '\n')
130     {
131         if (ch == ',')
132             n++;
133         i++;
134         fp.get(ch);
135     }
136     fp.close();*/
137     FILE *fp = fopen(argv[1], "r");
138     int n = 0;
139     char ch = fgetc(fp);
140     while ('\n' != ch)
141     {
142         if (ch == ',')
143             n++;
144         ch = fgetc(fp);
145     }
146     Det det;
147     det.InitializeSize(n+1);
148     det.InitializeValues(fp);
149     
150     for (int i = 0; i<det.order; i++)
151     {
152         puts(" ");
153         for (int j = 0; j<det.order; j++)
154             cout<<det.Matrix[i][j]<<'\t';
155     }
156     cout<<'\n'<<det.Calculate()<<endl;
157     fclose(fp);
158     return 0;
159 }

 

这篇关于C++行列式操作的文章就介绍到这儿,希望我们推荐的文章对大家有所帮助,也希望大家多多支持为之网!