[Fwd: Re: [Getdp] GetDP bug?]

[Michael J. Rivard]

Mauro,

Patrick and Christophe run your input files in a debugger to find the
bug and fix it.

-----Forwarded Message-----

From: Michael J. Rivard <rivard at sbcglobal.net>
To: Mauro Sgroi <maurosgroi at yahoo.it>
Cc: Patrick Dular <patrick.dular at ulg.ac.be>, Christophe Geuzaine <geuzaine at acm.caltech.edu>, GetDP Mailing-List <getdp at geuz.org>
Subject: Re: [Getdp] GetDP bug?
Date: Thu, 23 Jan 2003 09:57:31 -0800

"Segmentation violation" in any computer program means there's a bug in
the code. Patrick and/or Christophe may know a workaround.

On Thu, 2003-01-23 at 01:08, Mauro Sgroi wrote:
> I'm trying to solve the Poisson's equation with
> Neumann BC. In order to obtain a stable solution I
> need to fix the solution at a point (the other
> strategy would be to fix the mean value of the
> solution but I don't know how to do it in GetDP...).
> Anyway I obtain a "Segmentation Violation", as
> reported in the log file.
> Is it a bug or an error in my *.pro and *.geo files?
> Thanks in advance and best regards,
> Mauro Sgroi.
> 
> ______________________________________________________________________
> Yahoo! Cellulari: loghi, suonerie, picture message per il tuo telefonino
> http://it.yahoo.com/mail_it/foot/?http://it.mobile.yahoo.com/index2002.html
> ----
> 

> Group {
>   Line1 = Region[1] ;
>   Line2 = Region[2] ;
>   Line3 = Region[3] ;
>   Line4 = Region[4] ;
>   Point=  Region[100] ;
>   Domain = Region[200];
> }
> // Parameters
> // Iterative loop parameters
> NL_Eps=1.e-12;
> NL_Relax=1.;
> NL_NbrMax=1000;
> //////////////////////////////////////////
> Function{
> 
> }
> Constraint {
> {Name Dirichlet_phi; Type Assign;
>    Case {
> 	{ Region Point; Value 1.;}
>         }
>   }
> }
> /////////////////////////////////////////////////////////////////////////
> FunctionSpace {
> { Name phi_t ; Type Form0 ;
>     BasisFunction {
>       { Name wn ; NameOfCoef phin ; Function BF_Node ;
>         Support Domain; Entity NodesOf[ All ] ; }
> /*      { Name wn2 ; NameOfCoef phin2 ; Function BF_Node_2E ;
>         Support Domain; Entity EdgesOf[ All ] ; }*/
>     }
>     Constraint {
>         { NameOfCoef phin ; EntityType NodesOf ; NameOfConstraint Dirichlet_phi; }
>    }
> }
> }
> /////////////////////////////////////////////////////////////////////////
> Integration{
>  { Name Int_def;
>    Case { {Type Gauss;
>            Case { 
> 	        { GeoElement Line; NumberOfPoints 4;}
>                 { GeoElement Triangle; NumberOfPoints 4;}
>                 { GeoElement Quadrangle; NumberOfPoints 4;}
> 	     }	 
>            }
>          }
>  }
> }      
> /////////////////////////////////////////////////////////////////////////
> Jacobian {
>    { Name Vol ;
>      Case { { Region All ; Jacobian Vol ; } }
>    }
>    { Name Sur ;
>     Case { { Region All ; Jacobian Sur ; } }
>   }
> }
> /////////////////////////////////////////////////////////////////////////
> Formulation { 
>     {Name Coupled; Type FemEquation;	
>      Quantity{
>          {Name phi; Type Local; NameOfSpace phi_t;}
> 	}
>     Equation{
> 	Galerkin{[Dof{Grad phi},{Grad phi}];
> 	          In Domain; Integration Int_def; Jacobian Vol; }
>        	}
>     }
> }    
> /////////////////////////////////////////////////////////////////////////
> Resolution {
> 	{Name Solution;
>          System {
>               {Name Sys; NameOfFormulation Coupled; }
>               }
>             Operation { 
> 	            InitSolution[Sys];
> 		    IterativeLoop[NL_NbrMax,NL_Eps,NL_Relax] {
> 		      GenerateJac[Sys]; SolveJac[Sys];   
> 			}
>                   SaveSolution[Sys];             }
>        } 
> }
> /////////////////////////////////////////////////////////////////////////
> PostProcessing {
>    {Name Visual; NameOfFormulation Coupled; 
>     Quantity {
>         {Name phi; Value { Local { [{phi}]; In Domain; Jacobian Vol; } } }
> 	{Name e; Value { Local { [-{Grad phi}]; In Domain; Jacobian Vol; } } }
>       } 
>    } 
> }
> /////////////////////////////////////////////////////////////////////////
> PostOperation {
> 	{Name Map; NameOfPostProcessing Visual;
> 	 Operation {
>                 Print [phi, OnElementsOf Domain, File "phi.pos"];
> 	        Print [e, OnElementsOf Domain, File "e.pos"];
>           }
> 	}
> }
> ----
> 

> Point(1) = {0, 0, 0, 0.05};
> Point(2) = {1, 0, 0, 0.05};
> Point(3) = {1, 1, 0, 0.05};
> Point(4) = {0, 1, 0, 0.05};
> Line (1) = {1, 2};
> Line (2) = {2, 3};
> Line (3) = {3, 4};
> Line (4) = {4, 1};
> Line Loop (10) = {1, 2, 3, 4};
> Physical Point (100)= {1};
> Plane Surface (7) = {10};
> Physical Surface (200)= {7};
> ----
> 

> getdp poisson.pro -cal -msh poisson.msh
> 
> 
> 
> Loading   : Problem definition 'poisson.pro'
> Info      : Selected Resolution 'Solution'
> Loading   : Geometric data 'poisson.msh'
> Info      : System 'Sys' : Real
> P r e - P r o c e s s i n g . . .
> Loading   : Pre-Processing data 'poisson.pre'
> Resources : cpu 0.15000 s / mem 0 kb
> E n d   P r e - P r o c e s s i n g
> P r o c e s s i n g . . .
> Operation : InitSolution[Sys]
> Operation : IterativeLoop ...
> Info      : Non Linear Iteration 1 (Relaxation = 1)
> Operation : GenerateJac[Sys]
> Solver    : Loading parameter file 'solver.par'
> (0 %)                             Warning   : Generated system is of dimension zero
> Resources : cpu 0.15000 s / mem 0 kb
> Operation : SolveJac[Sys]
> Error     : Segmentation violation (invalid memory reference)
>             ------------------------------------------------------
>             You have discovered a bug in GetDP! You may report it
>             by e-mail (together with any helpful data permitting to
>             reproduce it) to <getdp at geuz.org>