function mesh_3d_plot (inc_e, inc_p) % Copyright 2000, J.E. Akin. All rights reserved. % function mesh_3d_plot () % ------------------------------------------------------ % Matlab program to calculate & plot 3-D FE meshes % ------------------------------------------------------ % c_x = x coordinates of nod_per_el line polygon % c_y = y coordinates of nod_per_el line polygon % inc_e = increment in element numbers on plot, if > 0 % inc_p = increment in node numbers on plot, if > 0 % msh_typ_nodes = connectivity list for elements, nt x nod_per_el % loop = corners for nod_per_el line polygon % lab_p = 1, if node points are circled lab_p = 0; % nod_per_el = Nodes per element % np = Number of Points % nt = Number of elements % pre_e = Element items before connectivity list pre_e = 0 ; % pre_p = Nodal items before coordinates % msh_bc_xyz = Nodal coordinates (with preceeding data) % t_x = x coordinates of nod_per_el corners % t_y = y coordinates of nod_per_el corners % x_bar = x-centroid of each element % xy = Coordinates of points, np x 2 % y_bar = y-centroid of each element % Read coordinate file and connectivity file % integer bc code, real xy pairs for np points (pre_p = 1) % Set control data: number of points load msh_bc_xyz.tmp ; pre_p = 1; np = size (msh_bc_xyz,1) ; % number of nodal points ns = size (msh_bc_xyz,2) - pre_p ; % dimension of space if ( np == 0 ) error ('Error missing file msh_bc_xyz.tmp') end % if error fprintf ('Read %g mesh coordinate pairs \n', np) % fprintf (' x y \n') x (np) = 0. ; % pre-allocate array x y (np) = 0. ; % pre-allocate array y z (np) = 0. ; % pre-allocate array y % msh_bc_xyz has: pre_p items then: x, y x = msh_bc_xyz (1:np, (pre_p+1)) ; % extract x column of xy if ( ns >= 2) y = msh_bc_xyz (1:np, (pre_p+2)) ; % extract y column of xy else y (1:np) = 0. ; end % if 1D if ( ns >= 3) z = msh_bc_xyz (1:np, (pre_p+3)) ; % extract z column of xy else z (1:np) = 0. ; end % if 1D % Set control data: number elements & nodes_per_element load msh_typ_nodes.tmp ; % nod_per_el nodes per element nt = size (msh_typ_nodes,1); % number of elements if ( nt == 0 ) error ('Error missing file msh_typ_nodes.tmp') end % if error nod_per_el = size (msh_typ_nodes,2) - pre_e -1 ; % nodes per element fprintf ('Read %g elements with %g nodes each \n', nt,nod_per_el) % fprintf (' Pt1 Pt2 Pt3 Pt4 Pt5 Pt6 Pt7 Pt8 \n') x_bar (nt) = 0. ; % pre-allocate array x_bar y_bar (nt) = 0. ; % pre-allocate array y_bar z_bar (nt) = 0. ; % pre-allocate array z_bar t_nodes (nod_per_el) = 0 ; % Optional pre-allocation t_x (nod_per_el) = 0 ; % Optional pre-allocation t_y (nod_per_el) = 0 ; % Optional pre-allocation t_z (nod_per_el) = 0 ; % Optional pre-allocation c_x (nod_per_el + 1) = 0 ; % Optional pre-allocation c_y (nod_per_el + 1) = 0 ; % Optional pre-allocation c_z (nod_per_el + 1) = 0 ; % Optional pre-allocation loop (nod_per_el + 1) = 0 ; % Optional pre-allocation % set constants [loop] = get_El_Loop (nod_per_el) ; %b fprintf ('Begin element plots:') % Initialize plots xmax = max (x) ; xmin = min (x) ; ymax = max (y) ; ymin = min (y) ; zmax = max (z) ; zmin = min (z) ; if ( zmax == zmin ) zmax = zmin + 1 ; if ( ymax == ymin ) ymax = ymin + 1 ; end % if end % if planar or axial clf % clear graphics axis ([xmin, xmax, ymin, ymax, zmin, zmax]) % set axes axis ('equal') % true shape style hold on % hold image for plots grid % add grid dots xlabel ('X') % add label ylabel ('Y') % add label zlabel ('Z') % add label title (['FE Mesh Geometry: ', int2str(nt), ... ' Elements, ', int2str(np),' Nodes']) % Plot input mesh points & label them if (lab_p == 1) % plot all points plot3 (x, y, z, 'b.') % mark each node end % if show labels if ( nargin == 0 ) % select increments % Show 20 nodes and 10 elements, or all for small mesh inc_p = floor(np/20) ; inc_e = floor(nt/10) ; if (inc_p == 0 ) inc_p = np - 1 ; end % if inc_p if (inc_e == 0 ) inc_e = nt - 1 ; end % if inc_e % Show all if a small mesh if ( np <= 20 ) inc_p = 1 ; end % if np if ( nt <= 10 ) inc_e = 1 ; end % if nt end % if no arguments if (inc_p > 0) % plot node numbers, if node in mesh in_mesh (1:np) = 0 ; % default to missing for i = 1:nt % loop all elements for j = 1:nod_per_el % loop its nodes in_mesh (msh_typ_nodes(i, j+1)) = 1; % flag as present end % for its nodes end % for all elements % disp (in_mesh) for i = 1:inc_p:np % convert to string if ( in_mesh (i) > 0 ) % it is present p_text = sprintf (' %g', i); % offset # from pt text (x(i), y(i), z(i), p_text) % plot pt number end % if present end % for all points end % if show labels disp (' ') % Loop over all elements for it = 1:nt ; % Extract corner connectivity t_nodes = msh_typ_nodes (it, (pre_e+2):(nod_per_el+pre_e+1)); % Extract corner coordinates t_x = x (t_nodes) ; % x at those nodes, only t_y = y (t_nodes) ; % y at those nodes, only t_z = z (t_nodes) ; % z at those nodes, only % Get the centroid x_bar (it) = sum (t_x' )/nod_per_el ; y_bar (it) = sum (t_y' )/nod_per_el ; z_bar (it) = sum (t_z' )/nod_per_el ; % Plot this polygon c_x = t_x (loop) ; % x for nod_per_el line polygon c_y = t_y (loop) ; % y for nod_per_el line polygon c_z = t_z (loop) ; % z for nod_per_el line polygon plot3 (c_x, c_y, c_z) % plot nod_per_el lines end % for over all elements % Finish the plots with polygon numbers if (inc_e > 0) % plot elem number, inclined plot3 (x_bar, y_bar, z_bar, 'g.') % centroid of each element for i = 1:inc_e:nt % convert to string t_text = sprintf (' %g', i); % offset # from pt text (x_bar(i), y_bar(i), z_bar(i), t_text, 'Rotation', 45) % incline end % for all polygons end % if show labels % -depsc -tiff % for an eps version % print -dpsc mesh_3d_plot hold off % fprintf ('Created file mesh_3d_plot.ps \n') % end of mesh_3d_plot