Calculate and highlight elements centers

Contents

Define geometry
Generate mesh
Get information about cell types
Map center of reference element to real element
Draw points at element centers

Define geometry

geom = mp.geoms.SquareGeom('mydomain', struct());

Generate mesh

mesher = mp.Mesher();
mesh = mesher.generate(geom, struct('lc', 0.4));

viewer = mp.Viewer();
viewer.show(mesh);

Get information about cell types

ct = mesh.cellTypes();
if (length(ct) > 1)
  error('This demo assumes mesh of single cell type')
end

info = mp_gmsh_types_info(ct);
center = sum(info.nodes, 1)/info.nnodes

% Calculate number of cells
cellSelector.dim = mesh.dim;
ncells = mesh.countElems(cellSelector);

center =

    0.3333    0.3333         0

Map center of reference element to real element

% Pre-allocate vectors for element centers for efficiency reason
xyz = zeros(ncells, 3);

% Iterate over cells
for i=1:ncells
  xyz(i, :) = mesh.geomTrans.transform(center, i);
end

Draw points at element centers

viewer.pointColor = 'red';
viewer.showPointsXY(xyz(:,1),xyz(:,2));

mp_manage_demos('report', 'mp_GeomTrans', true);