in C++ segmenatation fault

Please support our C++ advertiser: Intel Parallel Studio Home
Reply

•
•
Join Date: Aug 2006
Posts: 2
Reputation: bharat.bhooshan is an unknown quantity at this point 
Solved Threads: 0
bharat.bhooshan bharat.bhooshan is offline Offline
Newbie Poster

in C++ segmenatation fault

 
0
  #1
Aug 13th, 2006
I have a problem in C++(complier dev 4.9.9.2). My program have complie with no error but out put is wrong and not run show with massage “ some intermediated data is missing”. In debugging its show massage “segmentation Error” .

C++ Syntax (Toggle Plain Text) 
  1. #include<iostream>
 
#include<math.h>
#include<conio.h>
#include<fstream>
#include<dos.h>
#include<iomanip>
const int row=195;
const int col=235;
using namespace std;
float velocity (int,float,float,float,float);
int main()
{
 
ifstream in("data.txt");
ofstream out("vel.txt");
int **EL= (int**)malloc(row*col*sizeof(int) + col*sizeof(int*));
int **el= (int**)malloc(row*col*sizeof(int) + col*sizeof(int*));
int **SA= (int**)malloc(row*col*sizeof(int) + col*sizeof(int*));
int **RL= (int**)malloc(row*col*sizeof(int) + col*sizeof(int*));
int **LSD= (int**)malloc(row*col*sizeof(int) + col*sizeof(int*));
int **ASP= (int**)malloc(row*col*sizeof(int) + col*sizeof(int*));
int **SL= (int**)malloc(row*col*sizeof(int) + col*sizeof(int*));
int **X= (int**)malloc(row*col*sizeof(int) + col*sizeof(int*));
int **Y= (int**)malloc(row*col*sizeof(int) + col*sizeof(int*));
float **FC= (float**)malloc(row*col*sizeof(float) + col*sizeof(float*));
double **vel_g=(double**)malloc(row*col*sizeof(double) + col*sizeof(double*));
 
int i,m,n ,j,x,y,t,Max,k,k1;
 
float cvel,vel1,vel2,vel3,vel4,vel5,vel6,vel8,vel7,vel;
 
 
for(i=0;i<row;i++)
 
for( j=0; j<col;j++)
{
in>>el[i][j];
EL[i][j]=el[i][j];
in>>RL[i][j];
in>>SA[i][j];
in>>SL[i][j];
in>>FC[i][j];
in>>LSD[i][j];
in>>ASP[i][j];
}
 
for( k=0; k<row ;k++)
for( k1=0; k1<col;k1++)
{
Max=-2;
 
for(int i=0; i<row;i++)
for(int j=0; j<col;j++)
 
if(el[i][j]>Max)
{
Max=el[i][j];
x=j;
y=i;
}
 
X[k][k1]=x;
Y[k][k1]=y;
el[y][x]=-21;
cout<<k<<"\t"<<k1<<"\t"<<X[k][k1]<<endl; 
 
}
for(int a=0;a<row;a++)
for(int b=0;b<col;b++)
vel_g[a][b]= 0 ;
for(int k=0; k<row;k++)
for(int k1=0;k1<col;k1++)
{ 
 
n=X[k][k1];
m=Y[k][k1];
if(1==LSD[m][n]) 
{
while(SA[m][n]>=25)
{
vel = velocity(RL[m][n],FC[m][n],SL[m][n],SA[m][n],vel_g[m][n]); 
vel_g[m][n]= sqrt((vel_g[m][n]*vel_g[m][n])+(vel*vel)+(2*vel_g[m][n]*vel*cos(45*(22/7))));
t=ASP[m][n]; 
switch(t)
{
case(1): {m= m-1;n=n; vel=velocity(RL[m][n],FC[m][n],SL[m][n],SA[m][n],vel_g[m][n]);
vel_g[m][n]= sqrt((vel_g[m][n]*vel_g[m][n])+(vel*vel)+(2*vel_g[m][n]*vel*cos(45*(22/7))));
if(m<0||m>row||n<0||n>col) {cout<<"error1\n";} break;}
case(2): {m= m-1;n=n+1;vel=velocity(RL[m][n],FC[m][n],SL[m][n],SA[m][n],vel_g[m][n]);
vel_g[m][n]= sqrt((vel_g[m][n]*vel_g[m][n])+(vel*vel)+(2*vel_g[m][n]*vel*cos(45*(22/7)))); 
if(m<0||m>row||n<0||n>col) {cout<<"error2\n"; }break;}
case(3): {m= m;n=n+1;vel=velocity(RL[m][n],FC[m][n],SL[m][n],SA[m][n],vel_g[m][n]);
vel_g[m][n]= sqrt((vel_g[m][n]*vel_g[m][n])+(vel*vel)+(2*vel_g[m][n]*vel*cos(45*(22/7))));
if(m<0||m>row||n<0||n>col) {cout<<"error3\n"; }break;}
case(4): {m= m+1;n=n+1;vel=velocity(RL[m][n],FC[m][n],SL[m][n],SA[m][n],vel_g[m][n]);
vel_g[m][n]= sqrt((vel_g[m][n]*vel_g[m][n])+(vel*vel)+(2*vel_g[m][n]*vel*cos(45*(22/7)))); 
if(m<0||m>row||n<0||n>col) {cout<<"error4\n"; }break;}
case(5): {m= m+1;n=n;vel=velocity(RL[m][n],FC[m][n],SL[m][n],SA[m][n],vel_g[m][n]);
vel_g[m][n]= sqrt((vel_g[m][n]*vel_g[m][n])+(vel*vel)+(2*vel_g[m][n]*vel*cos(45*(22/7)))); 
if(m<0||m>row||n<0||n>col) {cout<<"error5\n"; }break;}
case(6): {m= m+1;n=n-1;vel=velocity(RL[m][n],FC[m][n],SL[m][n],SA[m][n],vel_g[m][n]);
vel_g[m][n]= sqrt((vel_g[m][n]*vel_g[m][n])+(vel*vel)+(2*vel_g[m][n]*vel*cos(45*(22/7))));
if(m<0||m>row||n<0||n>col) {cout<<"error6\n"; }break;}
case(7): {m= m;n=n-1;vel=velocity(RL[m][n],FC[m][n],SL[m][n],SA[m][n],vel_g[m][n]);
vel_g[m][n]= sqrt((vel_g[m][n]*vel_g[m][n])+(vel*vel)+(2*vel_g[m][n]*vel*cos(45*(22/7)))); 
if(m<0||m>row||n<0||n>col) {cout<<"error7\n"; }break;}
case(8): {m= m+1;n=n-1;vel=velocity(RL[m][n],FC[m][n],SL[m][n],SA[m][n],vel_g[m][n]);
vel_g[m][n]= sqrt((vel_g[m][n]*vel_g[m][n])+(vel*vel)+(2*vel_g[m][n]*vel*cos(45*(22/7))));
if(m<0||m>row||n<0||n>col) {cout<<"error8\n"; }break;}
 
 
}
 
} } 
 
 
} 
 
 
for(int c=0;c<row ;c++)
for(int d=0;d<col;d++)
{ out<<c<<"\t"<<d<<"\t";
out<<vel_g[c][d]<<'\n';
}
 
return 0;}
 
 
 
 
 
float velocity( int RL,float fric,float slope, float slopeangle, float ve)
{
int heg;
float D,b;
heg=RL;
b=fric;
if(ve>1000)
{
cout<<"\t"<<"heg="<<heg<<"\tb="<<b<<"\tve"<<ve<<"\t";
getch();
} 
const double g =9.781;
slopeangle=((slopeangle*(22/7))/180);
float x = (2*g*(heg-(b*slope*cos(slopeangle))));
if(x<0) x=0;
D=slope*cos(slopeangle);
float y = sqrt(x+(ve*ve));
if(y>100000)
{
cout<<"\td="<<D<<"\tfc="<<b<<"\tg="<<g<<"\theg="<<heg<<"\nve="<<ve<<"\ty="<<y<<"\n";
 
}
return y;
}
Last edited by cscgal; Aug 13th, 2006 at 1:08 pm.
Reply With Quote Quick reply to this message  
•
•
Join Date: Aug 2006
Posts: 5
Reputation: psycho^ is an unknown quantity at this point 
Solved Threads: 0
psycho^ psycho^ is offline Offline
Newbie Poster

Re: in C++ segmenatation fault

 
0
  #2
Aug 14th, 2006
int **EL= (int**)malloc(row*col*sizeof(int) + col*sizeof(int*));

EL[0] - this is first pointer in array
EL[0][0] - this is first pointer in array POINTED BY EL[0]

since you didnt initialize it (EL[0]), you have random data in there, so you access random memory - segmentation fault

you have to use EL[i*row+j] (or EL[i*col+j])
Reply With Quote Quick reply to this message  
•
•
Join Date: Jul 2006
Posts: 147
Reputation: Grunt has a spectacular aura about Grunt has a spectacular aura about 
Solved Threads: 12
Grunt's Avatar
Grunt Grunt is offline Offline
Junior Poster

Re: in C++ segmenatation fault

 
0
  #3
Aug 14th, 2006
@Bharat
<math.h>//deprecated in C++, use <cmath>
<conio.h>//Non-Standard
<dos.h>//Non-Standard
Last edited by Grunt; Aug 14th, 2006 at 12:59 pm.
The key to eliminating bugs from your code is learning from your mistakes.
Reply With Quote Quick reply to this message  
•
•
Join Date: Dec 2005
Posts: 5,850
Reputation: Salem has a reputation beyond repute Salem has a reputation beyond repute Salem has a reputation beyond repute Salem has a reputation beyond repute Salem has a reputation beyond repute Salem has a reputation beyond repute Salem has a reputation beyond repute Salem has a reputation beyond repute Salem has a reputation beyond repute Salem has a reputation beyond repute Salem has a reputation beyond repute 
Solved Threads: 751
Team Colleague
Salem's Avatar
Salem Salem is offline Offline
Void main'ers are DOOMed

Re: in C++ segmenatation fault

 
1
  #4
Aug 14th, 2006
> int **EL= (int**)malloc(row*col*sizeof(int) + col*sizeof(int*));
1. You didn't include stdlib.h
2. Since this seems to be C++, you should be using new anyway.
3. Since your sizes seem to be constant, why are you dynamically allocating anyway?

I see that lot adds up to at least a couple of MB, so that probably explains why you gave up on
int EL[row][col];

There are several ways out, which don't involve a lot of mess.

1. Make them static, you get the scope without the stack space
static int EL[row][col];

2. Dynamically allocate in one go, since the minor size is constant.
int (*EL)[col] = new int[row][col];
Note the placement of the ( ), very important you get these right.

3. Since this is C++, use a vector
vector< vector<int> > EL;
Reply With Quote Quick reply to this message  
•
•
Join Date: Aug 2006
Posts: 2
Reputation: bharat.bhooshan is an unknown quantity at this point 
Solved Threads: 0
bharat.bhooshan bharat.bhooshan is offline Offline
Newbie Poster

Re: in C++ segmenatation fault

 
0
  #5
Aug 15th, 2006
thankyoufor your suggestions. I used static array as mentioned by you that solves my problem. But now I need to modify the program whose array size is to be defined by the running time and hence a dyanimic array has to be used. I would therefore like to know as how to use dynamic array since the minor size is not known unlike what u have suggested for the same in
int (*EL)[col] = new int[row][col];
your kind help would see me run the program succesfully.

thanks and regards
Bharat
Reply With Quote Quick reply to this message  
•
•
Join Date: Dec 2005
Posts: 5,850
Reputation: Salem has a reputation beyond repute Salem has a reputation beyond repute Salem has a reputation beyond repute Salem has a reputation beyond repute Salem has a reputation beyond repute Salem has a reputation beyond repute Salem has a reputation beyond repute Salem has a reputation beyond repute Salem has a reputation beyond repute Salem has a reputation beyond repute Salem has a reputation beyond repute 
Solved Threads: 751
Team Colleague
Salem's Avatar
Salem Salem is offline Offline
Void main'ers are DOOMed

Re: in C++ segmenatation fault

 
0
  #6
Aug 15th, 2006
Like this
C++ Syntax (Toggle Plain Text) 
  1. #include <stdio.h>
  2. #include <stdlib.h>
  3. #include <string.h>
  4.  
  5. int ** alloc2D ( int row, int col ) {
  6.      int **p = malloc ( row * sizeof *p );      /* all the row pointers */
  7.      int *q  = malloc ( col * row * sizeof *q );/* all the data */
  8.      int r;
  9.      for ( r = 0 ; r < row ; r++ ) {            /* set pointers for each row */
  10.          p[r] = q;
  11.          q += col;
  12.      }
  13.      return p;
  14. }
  15.  
  16. void free2D ( int **arr ) {
  17.      free( arr[0] );    /* free all the data */
  18.      free( arr );       /* free the row pointers */
  19. }
  20. int main(void)
  21. {
  22.   int **arr = alloc2D ( 10, 20 );
  23.   int r, c;
  24.   for ( r = 0 ; r < 10 ; r++ ) {
  25.       for ( c = 0 ; c < 20 ; c++ ) {
  26.           arr[r][c] = 0;
  27.       }
  28.   }
  29.   free2D( arr );
  30.   return 0;
  31. }
Reply With Quote Quick reply to this message  
Reply

Quick Reply to Thread
This thread is more than three months old.
Perhaps start a new thread instead?
•
•
•
•
•
•
•
•
Message:
•
•
•
•



Similar Threads
Other Threads in the C++ Forum
Thread Tools Search this Thread



Tag cloud for C++
api application array arrays based beginner binary bmp c++ c/c++ calculator char char* class classes code compile compiler console conversion convert count data delete deploy dll download dynamic dynamiccharacterarray encryption error file format forms fstream function functions game givemetehcodez graph gui homeworkhelp iamthwee ifstream input int java lib library linker list loop looping loops map math matrix memory microsoft newbie news number numbertoword output pointer problem program programming project python random read recursion recursive reference rpg simple sorting string strings struct temperature template templates test text text-file tree url variable vector video visual visualstudio void win32 windows winsock wordfrequency wxwidgets
About Us | Contact Us | Advertise | DaniWeb | Acceptable Use Policy | RSS Feed

©2003 - 2009 DaniWeb® LLC