N Point Circular Convolution of sequences

 N Point Circular Convolution of  sequences

Problem Statement : Find the N point circular convolution of given two sequences. Test it for linear convolution

1:  #include<graphics.h>  
2:  #include<iostream.h>  
3:  #include<conio.h>  
4:  #include<stdlib.h>  
5:  void main(void)  
6:  {  
7:   int sample,impulse,sam[10],imp[10],out[10][10],outp[10]={0},i;  
8:   int gd=DETECT,gm,maxx,maxy,j;  
9:   char str[5];  
10:   initgraph(&gd,&gm,"c:\\tc\\bgi");  
11:   maxx=getmaxx();   // Returns maximum x or y screen coordinate  
12:   maxy=getmaxy();  
13:   cout<<"\n\tEnter the number of element in sample sequence::";  
14:   cin>>sample;  
15:   cout<<"\n\tEnter the number of element in impulse sequence::";  
16:   cin>>impulse;           //input impulse & sample sequence  
17:   cout<<"\n\tEnter the sample sequence";  
18:   for(i=0;i<sample;i++)  
19:   cin>>sam[i];  
20:   cout<<"\n\tEnter the impusle sequence";  
21:   for(i=0;i<impulse;i++)  
22:   cin>>imp[i];  
23:   for(i=0;i<sample;i++)  
24:   for(j=0;j<impulse;j++)  
25:    out[i][j]=sam[i]*imp[j];  
26:   for(i=0;i<impulse;i++)  
27:   for(j=0;j<sample;j++)  
28:    outp[j+i]=outp[j+i]+out[j][i];  
29:   int samp=i+j-1;  
30:   setcolor(RED);  
31:   line(0,maxy/2,maxx,maxy/2);  
32:   line(maxx/2,0,maxx/2,maxy);  
33:   setcolor(GREEN);  
34:   for(i=0;i<samp;i++)  
35:   {  
36:    line(maxx/2+i*30,maxy/2,maxx/2+i*30,maxy/2-outp[i]*5);  
37:    moveto(maxx/2+i*30,maxy/2-outp[i]*5-10);  
38:    itoa(outp[i],str,10);        //converts integer to string  
39:    outtext(str);  
40:   }  
41:   getch();  
42:  }  

Using Graph

1:  #include<graphics.h>  
2:  #include<iostream.h>  
3:  #include<conio.h>  
4:  #include<stdlib.h>  
5:  void main(void)  
6:  {  
7:   int sample,impulse,sam[10]={0},imp[10]={0},outp[10]={0},i;  
8:   int gd=DETECT,gm,maxx,maxy,j,k,sum;  
9:   char str[5];  
10:   initgraph(&gd,&gm,"e:\\tc\\bgi");  
11:   maxx=getmaxx();   // Returns maximum x or y screen coordinate  
12:   maxy=getmaxy();  
13:   cout<<"\n\tEnter the number of element in sample sequence::";  
14:   cin>>sample;  
15:   cout<<"\n\tEnter the number of element in impulse sequence::";  
16:   cin>>impulse;           //input impulse & sample sequence  
17:   cout<<"\n\tEnter the sample sequence";  
18:   for(i=0;i<sample;i++)  
19:   cin>>sam[i];  
20:   cout<<"\n\tEnter the impusle sequence";  
21:   for(i=0;i<impulse;i++)  
22:   cin>>imp[i];  
23:   for(k=0;k<(sample+impulse-1);k++)  
24:   {  
25:   cleardevice();  
26:   setcolor(MAGENTA);  
27:   outtextxy(maxx/2+40,0,"Sample Sequence x(n)");  
28:   outtextxy(maxx/2+40,165,"Impulse Response h(-n+k)");  
29:   outtextxy(maxx/2+40,330,"x(k)*h(-k+n)");  
30:   setcolor(RED);  
31:   line(maxx/2,0,maxx/2,maxy);  
32:   line(0,maxy/6,maxx,maxy/6);  
33:   line(0,maxy/2,maxx,maxy/2);  
34:   line(0,5*maxy/6,maxx,5*maxy/6);  
35:   setlinestyle(DOTTED_LINE,1,1);  
36:   setcolor(GREEN);  
37:   line(0,maxy/3,maxx,maxy/3);  
38:   line(0,2*maxy/3,maxx,2*maxy/3);  
39:   setlinestyle(SOLID_LINE,1,3);  
40:   for(i=0;i<sample;i++)  
41:   {  
42:    line(maxx/2+i*30,maxy/6,maxx/2+i*30,maxy/6-sam[i]*2);  
43:    if(sam[i]>=0)  
44:        moveto(maxx/2+i*30,maxy/6-sam[i]*2-10);  
45:    else  
46:         moveto(maxx/2+i*30,maxy/6-sam[i]*2+10);  
47:    itoa(sam[i],str,10);        //converts integer to string  
48:    outtext(str);  
49:   }  
50:   for(i=impulse-1;i>=0;i--)  
51:   {  
52:    line(maxx/2-(i-k)*30,maxy/2,maxx/2-(i-k)*30,maxy/2-imp[i]*2);  
53:    if(imp[i]>=0)  
54:        moveto(maxx/2-(i-k)*30,maxy/2-imp[i]*2-10);  
55:    else  
56:         moveto(maxx/2-(i-k)*30,maxy/2-imp[i]*2+10);  
57:    itoa(imp[i],str,10);        //converts integer to string  
58:    outtext(str);  
59:   }  
60:   int temp=k;  
61:   sum=0;  
62:   for(i=k;i>=0;i--)  
63:   {  
64:    sum+=sam[i]*imp[temp-i];  
65:    line(maxx/2+i*30,5*maxy/6,maxx/2+i*30,5*maxy/6-sam[i]*imp[temp-i]*2);  
66:    if(outp[i]>=0)  
67:        moveto(maxx/2+i*30,5*maxy/6-sam[i]*imp[temp-i]*2-10);  
68:    else  
69:         moveto(maxx/2+i*30,5*maxy/6-sam[i]*imp[temp-i]*2+10);  
70:    itoa(sam[i]*imp[temp-i],str,10);        //converts integer to string  
71:    outtext(str);  
72:   }  
73:   outp[k]=sum;  
74:   outtextxy(330,maxy-10,"y(");  
75:   itoa(k,str,10);        //converts integer to string  
76:   outtextxy(330+15,maxy-10,str);  
77:   outtextxy(330+30,maxy-10,")::");  
78:   itoa(outp[k],str,10);        //converts integer to string  
79:   outtextxy(390,maxy-10,str);  
80:   setcolor(YELLOW);  
81:   outtextxy(20,maxy-10,"Press Any Key to Continue::");  
82:   getch();  
83:   }  
84:   cleardevice();  
85:   outtextxy(maxx/2+20,20,"Output y(n)");  
86:   setcolor(RED);  
87:   setlinestyle(SOLID_LINE,1,1);  
88:   line(maxx/2,0,maxx/2,maxy);  
89:   line(0,maxy/2,maxx,maxy/2);  
90:   setcolor(GREEN);  
91:   setlinestyle(SOLID_LINE,1,3);  
92:   for(i=0;i<(sample+impulse-1);i++)  
93:   {  
94:    line(maxx/2+i*30,maxy/2,maxx/2+i*30,maxy/2-outp[i]*2);  
95:    if(sam[i]>=0)  
96:        moveto(maxx/2+i*30,maxy/2-outp[i]*2-10);  
97:    else  
98:         moveto(maxx/2+i*30,maxy/2-outp[i]*2+10);  
99:    itoa(outp[i],str,10);        //converts integer to string  
100:    outtext(str);  
101:   }  
102:   getch();  
103:   closegraph();  
104:  }