In this article we investiguate in detail how to mesh a geometry with the toolbox CGLAB:

https://atoms.scilab.org/toolboxes/cglab/

nodes_mesh

 

//Meshing in Scilab
//Requires CGLAB toolbox
atomsInstall 'cglab'

    nx = 10;
    ny = 10;
    Lx = 0.45;
    Ly = 0.40;
    
    [x, y] = meshgrid(linspace(0, Lx, nx), linspace(0, Ly, ny))
    
    n = nx * ny;
    PosNoeuds = [x(:), y(:)]; // nodal coordinates
    
    // Borders are defined with Lbord
    eps = 0.0001;
    Lbord = find(PosNoeuds(:, 1) < eps );
    Lbord = union(Lbord, find(PosNoeuds(:, 1) > Lx - eps));
    Lbord = union(Lbord, find(PosNoeuds(:, 2) < eps));    
    Lbord = union(Lbord, find(PosNoeuds(:, 2) > Ly - eps));
    
    scf();    
    plot(PosNoeuds(:, 1), PosNoeuds(:, 2), 'b.');

    // Displacement of the origin at the node (0.5 Lx,O.5 Ly)
    PosNoeuds = PosNoeuds - ones(n , 1)*[Lx/2, Ly/2];

     // triangular elements
    tri = delaunay_2(PosNoeuds(:, 1)', PosNoeuds(:, 2)');
    [nbtri2,nb2] = size(tri);
    tri2 = [tri tri(:,1)];
    
    for k = 1:nbtri2
        plot2d(x(tri2(k,:)),y(tri2(k,:)),style = 2);
    end

To read more on the subject:

CGLAB Toolbox for Geometric Algorithms