Re: [ESPResSo-users] Implementation of S2 code

[Axel Arnold]

Dear Muhammad,

the interface code is good, so chances are fairly good that the mistake is 
somewhere in your code. Best thing is, if you run Espresso in the debugger, 
gdb, and check where actually the segfault occurs. For debugging, you best 
recompile Espresso with CFLAGS="-g -O0" so that no variables are optimized 
out. Then you can use e.g. gdb as usual. If you haven't used a debugger so 
far, you will probably need to get someone local to help; there is nothing 
special about debugging Espresso, so anybody familiar with C will be ok.

Many regards,
Axel

On Saturday 01 October 2011, Muhammad Anwar wrote:
> Hello,
> Dear Users and developers,
> I am trying to implement orientational order parameter algorithm in
> ESPResSo,  i compiled it successfully, the problem i am finding is ,
> when i try to calculate the parameter, it give result for one step then
> give message of "segmentation fault".  I am following
> "lipid_orient_order" code to learn how to implement in espresso because
> it is very close to my work.  The  code  is like this
> 
> int orient_order_S2(double* result)
> {
>     *result = 0.0;
> 
> 
>    //my code
> 
>    *result = -2*z2;
>     return TCL_OK;
> }
> 
> *and parse function is
> *
> static int tclcommand_analyze_parse_orient_order_S2(Tcl_Interp *interp,
> int argc, char **argv)
> {
> double result;
> char buffer[TCL_DOUBLE_SPACE];
>   int i , j ;
>   result = 0;
> 
>   if (n_total_particles <= 1) {
>     Tcl_AppendResult(interp, "(not enough particles)",
>              (char *)NULL);
>     return (TCL_OK);
>   }
> 
>   /* Do the calculation */
>     if ( orient_order_S2(&result) != TCL_OK ) {
>     Tcl_AppendResult(interp, "Error calculating orientational order ",
> (char *)NULL);
>     return TCL_ERROR;
>   }
> 
>       Tcl_PrintDouble(interp, result, buffer);
>       Tcl_AppendResult(interp, buffer, (char *)NULL);
>       return TCL_OK;
>       Tcl_AppendResult(interp, "Error calculating orientational order ",
> (char *)NULL);
>       return TCL_ERROR;
> }
> 
> I will really appreciate if any body can help about this problem.
> Thanks and have a nice day.
> 
> Best Regards,
> Muhammad Anwar


-- 
JP Dr. Axel Arnold      Tel: +49 711 685 67609
ICP, Universität Stuttgart      Email: address@hidden
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70569 Stuttgart, Germany