What's wrong with my geometry definition that I have to mesh after?

I can't get my geometry to mesh using MATLAB's mesher through the initmesh function. The error message is so brief that I can't identify the source of the error.

Here is the geometry definition :

%----------------       Geometric parameters        ----------------------%

% Plate

Ep_plaque = 5e-3;
R_plaque = 20e-2;

% Coil

R_int_ind   = 5e-2;
R_ext_ind   = 15e-2;
Ep_ind      = 2e-3;
Airgap      = 2e-3; 

% Airbox 

R_air = 5*R_plaque;
H_air = 100*Ep_plaque;


% Plate
x1 = 0;             y1 = 0;
x2 = R_plaque;      y2 = 0;
x3 = R_plaque;      y3 = Ep_plaque;
x4 = 0;             y4 = Ep_plaque;

% Coil
x100 = R_int_ind;         y100 = -Airgap-Ep_ind;
x101 = R_ext_ind;         y101 = -Airgap-Ep_ind;
x102 = R_ext_ind;         y102 = -Airgap;
x103 = R_int_ind;         y103 = -Airgap;

% Air
x20 = 0;            y20 = -H_air/2;
x21 = R_air;        y21 = -H_air/2;
x22 = R_air;        y22 =  H_air/2;
x23 = 0;            y23 =  H_air/2;

% zone 1  : air
% zone 10  : plate
% zone 100 : coil

n_couches = 2; 
Ep_layer = [5.2e-7 2.3e-6];
g_couche = []; 
xs1 = R_plaque;
xs2 = 0;
xs3 = R_plaque;
xs4 = 0;

for i = 1:n_couches
    ys1 = Ep_layer(i); 
    ys2 = ys1; 
    if i == 1 
        g_couche = [  g_couche ; 
                      2 x1   x2   y1   y2   10  1    0   0   0;...
                      2 x2   xs1  y2   ys1  10  1    0   0   0;...
                      2 xs1  xs2  ys1  ys2  10  39    0   0   0;...
                      2 xs2  x1   ys2  y1   10  0    0   0   0;...
                  ];
    elseif i == n_couches
        ys3 = Ep_layer(1);
        ys4 = ys3;
        g_couche= [ g_couche ;
            2  xs3  xs1 ys3 ys1   39   1    0 0 0;...
            2  xs1  xs2 ys1 ys2   39   50    0 0 0;...
            2  xs2  xs4 ys2 ys4   39   0    0 0 0;...
            ] ;
    end
end 

g_plaque = [2 xs1 x3  ys1 y3  50 1 0 0 0; ...
            2 x3  x4  y3  y4  50 1 0 0 0;...
            2 x4  xs2 y4  ys2 50 0 0 0 0;...
            ]; 

g_ind_air = [2 x100 x101 y100 y101 100 1   0   0   0;...
             2 x101 x102 y101 y102 100 1   0   0   0;...
             2 x102 x103 y102 y103 100 1   0   0   0;...
             2 x103 x100 y103 y100 100 1   0   0   0;...
             2 x20  x21  y20  y21  1   0   0   0   0;...
             2 x21  x22  y21  y22  1   0   0   0   0;...
             2 x22  x23  y22  y23  1   0   0   0   0;...
             2 x23  x4   y23  y4   1   0   0   0   0;...
             2 x1   x20  y4   y20  1   0   0   0   0;...
    ];

g = [ g_couche.' g_ind_air.' g_plaque.']; 

Here is how I call it and try to mesh it :

[p,e,t]=initmesh(g,'MesherVersion', 'R2013a');

Error using pdevoron
Geometry error.

Error in pderespe (line 30)
[p,t,c,h]=pdevoron(p,t,c,h,x,y,tol,Hmax,Hgrad);

Error in initmesh (line 166)
[p,e,t,c]=pderespe(g,p,e,t,c,Hmax,tol,tol2,Hmax,Hgrad);

You can visualize the geometry using :

pdegplot(g,'EdgeLabels','off');   

Answer 1

[Govind KM]

Hi @hakim oueslati,

This error is usually caused by very small connected meshes or alignment issues within the geometry. More information on this error along with resolution steps can be found in the following MATLAB Answers post:

https://www.mathworks.com/matlabcentral/answers/93590-why-does-using-the-partial-differential-equation-toolbox-result-in-the-error-error-using-pd