Killed message in gcc

Dev Shed Forums Sponsor:

December 27th, 2012, 01:21 PM

lida_marti

Registered User

Join Date: Dec 2012

Posts: 2

Time spent in forums: 52 m 33 sec
Reputation Power: 0

Killed message in gcc

Hello,

I'm having trouble when running a program. It compiles without any problem using gcc but when it's running, after some iterations, it stops and appears "killed" on the terminal. It's a program about how an ideal gas in a box evolves in time. When I increase the number of particles in the box or increase the time I want the gas to evolve it stops itself. Any help on how to solve it? Why does the killed message appears? Thanks!!!

December 27th, 2012, 02:08 PM

salem

Contributed User

Join Date: Jun 2005

Posts: 3,905

Folding Points: 153 Folding Title: Novice Folder

Time spent in forums: 2 Months 3 Weeks 4 Days 1 h 2 m 3 sec
Reputation Power: 1774

The primary reason would be bugs in your code. Saying what is likely to be wrong would require you to post some code.

A secondary reason may be that your program takes up too much time / memory / file handles etc.
http://ss64.com/bash/ulimit.html

__________________
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper

December 27th, 2012, 03:27 PM

lida_marti

Registered User

Join Date: Dec 2012

Posts: 2

Time spent in forums: 52 m 33 sec
Reputation Power: 0

this is a function used in main called time. ax, ay, az are the position of the particles in the box and bx by and bz are their velocity. N is the number of particles. T the total time, h the time between steps. This shows a killed message when running it when N or T are big (10000) (or h small). In fact we need N to be of the order of E23, is there any way that in a normal computer we can do that?

Quote:

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>
#include "functions.h"

double *time(double *x,double *y,double *z,double *vx,double *vy,double *vz,long int N, double h, long int T,double **bx,double **by,double **bz)
{

//we declare the variables
int i, k, t, l, m;
double **ax, **ay, **az;

t=(int)(T/h);

//allocation of memory
ax= (double**) calloc(N,sizeof(double*));
for(l=0; l<N; l++)
{
ax[l]= (double*) calloc(t+2,sizeof(double));
}
ay= (double**) calloc(N,sizeof(double*));
for(l=0; l<N; l++)
{
ay[l]= (double*) calloc(t+2,sizeof(double));
}
az= (double**) calloc(N,sizeof(double*));
for(l=0; l<N; l++)
{
az[l]= (double*) calloc(t+2,sizeof(double));
}

//we set the initial value of the variables
for (i=0;i<N;i++)
{
ax[i][0]=x[i];
ay[i][0]=y[i];
az[i][0]=z[i];

bx[i][0]=vx[i];
by[i][0]=vy[i];
bz[i][0]=vz[i];
}

//we evolve the system of particles, making them move according to their speed

k=0;

do{
i=0;
do
{

if (ax[i][k]>=1)
{ bx[i][k+1]=-bx[i][k];}
else if (ax[i][k]<=0)
{ bx[i][k+1]=-bx[i][k];}
else { bx[i][k+1]=bx[i][k];}

if (ay[i][k]>=1)
{ by[i][k+1]=-by[i][k];}
else if (ay[i][k]<=0)
{ by[i][k+1]=-by[i][k];}
else { by[i][k+1]=by[i][k];}

if (az[i][k]>=1)
{ bz[i][k+1]=-bz[i][k];}
else if (az[i][k]<=0)
{ bz[i][k+1]=-bz[i][k];}
else { bz[i][k+1]=bz[i][k];}

ax[i][k+1]=ax[i][k]+bx[i][k+1]*h;
ay[i][k+1]=ay[i][k]+by[i][k+1]*h;
az[i][k+1]=az[i][k]+bz[i][k+1]*h;

i++;

} while (i<N);
k++;
}while ((h*k)<T);

m=k;

//free memory

for(l=0; l<N; l++)
{
free(ax[l]);
free(ay[l]);
free(az[l]);

}
free(ax);
free(ay);
free(az);

return 0;

}

December 27th, 2012, 03:38 PM

b49P23TIvg

Contributing User

Join Date: Aug 2011

Posts: 3,458

Time spent in forums: 1 Month 2 Weeks 4 Days 6 h 26 m 43 sec
Reputation Power: 403

I suggest you simulate particles in a small box.
With a million particles, or perhaps debug your program with 9 ideal gas particles.
I'm certain, absolutely certain that you can figure out the size of your box for N particles to make the density you need.

My computer has only 6e22 words of memory, so Mr. Avagadro can't work on MY computer.

__________________
[code]Code tags[/code] are essential for python code!

Killed message in gcc

Developer Shed Advertisers and Affiliates