function color_el_at_nodes (P_1, P_2, P_inc, mesh) % defaults: 1, np, (np-1)/7, 1 % Copyright 2000, J.E. Akin. All rights reserved. % ------------------------------------------------------ % Plot 2-D FE elements from nodes P_1 to P_2 in increments % P_inc and include full mesh if mesh=1 % ------------------------------------------------------ % 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 %-error on plot, if > 0 inc_e = 1 ; % 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 pre_p = 1; % 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 ; np = size (msh_bc_xyz,1) ; % number of nodal points fprintf ('Read %g mesh coordinate pairs \n', np) % fprintf (' x y \n') % 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 in mesh nod_per_el = size (msh_typ_nodes,2) - pre_e -1 ; % nodes per element fprintf ('Read %g elements connections \n', nt) if ( nargin == 0) P_1=1; P_2=np ; P_inc= ceil((P_2 - P_1)/7) ; mesh = 1 ; elseif ( nargin == 1 ) P_2=P_1 ; P_inc=1 ; mesh = 1 ; elseif ( nargin == 2 ) P_inc= 1 ; % ceil((P_2 - P_1)/7) ; mesh = 1 ; elseif ( nargin == 3 ) mesh = 1 ; end % if P_check = [P_1:P_inc:P_2] P_n = size (P_check, 2) ; x (np) = 0. ; % pre-allocate array x y (np) = 0. ; % pre-allocate array y % x_bar (nt) = 0. ; % pre-allocate array x_bar % y_bar (nt) = 0. ; % pre-allocate array y_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 c_x (nod_per_el + 1) = 0 ; % Optional pre-allocation c_y (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) ; % msh_bc_xyz has: pre_p items then: x, y x = msh_bc_xyz (1:np, (pre_p+1)) ; % extract x column of xy y = msh_bc_xyz (1:np, (pre_p+2)) ; % extract y column of xy % Initialize plots %b fprintf ('Begin element error value plots: \n') xmax = max (x) ; xmin = min (x) ; ymax = max (y) ; ymin = min (y) ; %b xdiff = xmax - xmin ; ydiff = ymax - ymin ; %b if ( ydiff == 0.0 ) %b ydiff = 0.5 ; % allow for 1-D mesh (with y == 0) %b end % if no y coordinates %b xmax = xmax + xdiff/10; ymax = ymax + ydiff/10; %b xmin = xmin - xdiff/10; ymin = ymin - ydiff/10; clf % clear graphics axis ([xmin, xmax, ymin, ymax]) % set axes axis ('equal') % true shape style hold on % hold image for plots grid % add grid dots xlabel (['X: ', int2str(nt),' Elements (with ', ... int2str(nod_per_el), ' nodes)']) ylabel (['Y: ', int2str(np),' Nodes']) format short % Plot input mesh points if (lab_p == 1) % plot all points plot (x, y, 'b.') % mark each node end % if show labels % Show 20 nodes and 50 elements inc_p = floor(np/20) ; inc_e = floor(nt/50) ; 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 <= 50 ) inc_e = 1 ; end % if nt inc_e=0 ; inc_p=0 ; % Loop over all elements Rank = 8 ; First = 0 ; for it = 1:nt ; % ckeck all elements for nodes on list % Extract corner connectivity t_nodes = msh_typ_nodes (it, (pre_e+2):(nod_per_el+pre_e+1)); Given = 0; for k=1:P_n ; if ( any (t_nodes == P_check(k)) ) % then node on elem Given = 1 ; break % out of for k end % if any end % for k if ( Given ) % then color element fprintf ('at node %g \n', P_check(k)) if ( First == 0 ) First = it ; end % if first element found Last = it ; % Rank the colors Rank = Rank - 1 ; if ( Rank == 0 ) Rank = 7 ; end % if % scale colors as one set of 7 if ( Rank == 7) ; color = 'r' ; % red elseif ( Rank == 6) ; color = 'y' ; % yellow elseif ( Rank == 5) ; color = 'g' ; % green elseif ( Rank == 4 ) ; color = 'b' ; % blue elseif ( Rank == 3 ) ; color = 'c' ; % cyan elseif ( Rank == 2 ) ; color = 'm' ; % magenta elseif ( Rank == 1 ) ; color = 'w' ; % white else ; color = 'k' ; % black (impossible ??) end % if for rank color % Extract corner coordinates t_x = x (t_nodes) ; % x at those nodes, only t_y = y (t_nodes) ; % y at those nodes, only % Get the centroid x_bar = sum (t_x' )/nod_per_el ; y_bar = sum (t_y' )/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 fill (c_x, c_y, color) % fill element color fprintf ('found element %g \n', it) % plot elem number, inclined t_text = sprintf ('%g', it); % offset # from pt text (x_bar, y_bar, t_text, 'Rotation', 45) % incline end % if given node on element end % for if ( mesh == 1 ) % add all element outlines 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 % 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 plot (c_x, c_y) % plot element color end % for full mesh end % if mesh title(['Selected Elements (', int2str(First), ' to ', ... int2str(Last), ') at Nodes ', int2str(P_1),' : ', ... int2str(P_inc),' : ', int2str(P_2)]) % -depsc -tiff % for an eps version %b print -dpsc color_el_at_node hold off %b fprintf ('Created file color_el_at_node.ps \n') % end of color_el_at_nodes