![01 #include<stdio.h>
02 #include<conio.h>
03 #include<math.h>
04 float fun(float x, float y)
05 {
06 return(0.1*x*x+0.1*y*y);
07 }
08 void main()
09 {
10 int i,j,N;
11 float x0,y0,x,h,y,k[20][20],Y[20],n,p,a;
12 clrscr();
13
14
15 printf("n Enter the initial value of X:");
16 scanf("%f",&x0);
17 printf("n Enter the initial value of Y:");
18 scanf("%f",&y0);
19 printf("n Enter the given value of X:");
20 scanf("%f",&x);
21 printf("n Enter the value of step size h:");
22 scanf("%f",&h);
23 n=(x-x0)/h;
24 N=(int)n;
25 printf("nNumber of iterations is:%dn",N);
26
27 for(i=1;i<=N;i++)
28 {
29 k[i][1]=h*fun(x0,y0);
30 k[i][2]=h*fun(x0+0.5*h,y0+0.5*k[i][1]);
31 k[i][3]=h*fun(x0+0.5*h,y0+0.5*k[i][2]);
32 k[i][4]=h*fun(x0+h,y0+k[i][3]);
33 k[i][5]=(1.0/6.0)*(k[i][1]+2*k[i][2]+2*k[i][3]+k[i][4]);
34 x0=x0+h;
35 y=y0+k[i][5];
36 Y[i]=y;
37 y0=y;
38 }
39
40 printf("nk1ttk2ttk3ttk4ttkttYn");](https://image.slidesharecdn.com/rungekutta-120401111401-phpapp01/85/Runge-kutta-C-programme-1-320.jpg)
![41 x0=x0-n*h;
42 p=h;
43
44 for(i=1;i<=N;i++)
45 {
46 for(j=1;j<=5;j++)
47 {
48 printf("%ft",k[i][j]);
49 }
50 a=x0+h;
51 printf("tY(%f)=%f",a,Y[i]);
52 printf("n");
53 h=h+p;
54 }
55
56
57 printf("nThe final value of Y:t%f",y);
58
59 getch();
60 }](https://image.slidesharecdn.com/rungekutta-120401111401-phpapp01/85/Runge-kutta-C-programme-2-320.jpg)
Runge kutta C programme
- 1. 01 #include<stdio.h> 02 #include<conio.h> 03 #include<math.h> 04 float fun(float x, float y) 05 { 06 return(0.1*x*x+0.1*y*y); 07 } 08 void main() 09 { 10 int i,j,N; 11 float x0,y0,x,h,y,k[20][20],Y[20],n,p,a; 12 clrscr(); 13 14 15 printf("n Enter the initial value of X:"); 16 scanf("%f",&x0); 17 printf("n Enter the initial value of Y:"); 18 scanf("%f",&y0); 19 printf("n Enter the given value of X:"); 20 scanf("%f",&x); 21 printf("n Enter the value of step size h:"); 22 scanf("%f",&h); 23 n=(x-x0)/h; 24 N=(int)n; 25 printf("nNumber of iterations is:%dn",N); 26 27 for(i=1;i<=N;i++) 28 { 29 k[i][1]=h*fun(x0,y0); 30 k[i][2]=h*fun(x0+0.5*h,y0+0.5*k[i][1]); 31 k[i][3]=h*fun(x0+0.5*h,y0+0.5*k[i][2]); 32 k[i][4]=h*fun(x0+h,y0+k[i][3]); 33 k[i][5]=(1.0/6.0)*(k[i][1]+2*k[i][2]+2*k[i][3]+k[i][4]); 34 x0=x0+h; 35 y=y0+k[i][5]; 36 Y[i]=y; 37 y0=y; 38 } 39 40 printf("nk1ttk2ttk3ttk4ttkttYn");
- 2. 41 x0=x0-n*h; 42 p=h; 43 44 for(i=1;i<=N;i++) 45 { 46 for(j=1;j<=5;j++) 47 { 48 printf("%ft",k[i][j]); 49 } 50 a=x0+h; 51 printf("tY(%f)=%f",a,Y[i]); 52 printf("n"); 53 h=h+p; 54 } 55 56 57 printf("nThe final value of Y:t%f",y); 58 59 getch(); 60 }