navier2d.m

ZEUS is a family of Eulerian (grid based) Magneto-Hydrodynamic codes (MHD) for use in astrophysics,

                'gradient'  ,gradient);

% Set GUI data
set(gcf,'UserData',bcdata);

return


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function help_bc(varargin)

% Quick help for the BC window

helptext = {'Quick help for boundary conditions.'
            ''
            ['This console shows the boundary edges of the mesh, with the '  , ...
             'edge midpoints plotted. Boundary conditions must be specified ', ...
             'for each edge.']
            ''
            ['Edges are first selected using the mouse by pressing the '   , ...
             '"Select" button. Multiple edges can be selected/de-selected ', ...
             'using this mode. "Clear" will clear the selection.']
            ''
            ['Boundary conditions are then specified for the highlighted edges ', ...
             'by pressing the "Set" button. This will prompt the user for the ', ...
             'boundary condition type.']
            ''
            'Velocity boundary conditions are used when the velocity is known'
            'Pressure boundary conditions are used for outlets/outflows'
            ''
            ['If a velocity type is chosen the user is then asked to enter the ', ...
             'xy velocity components.']
            ''
            'Velocity conditions are shown in blue, pressure conditions in green.'
            ''
            'Boundary conditions can be reassigned.'
           };

uiwait(msgbox(helptext,'Help','none')); 

return


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function clear_sel(varargin)

% Clear current mouse selection 

% Get GUI data
fig    = gcf; 
ax     = gca;
bcdata = get(fig,'UserData');

% Boundary edge geometry
e  = bcdata.e;
be = bcdata.be;
p  = bcdata.p;
pe = bcdata.pe;
pm = 0.5*(p(e(be,1),:)+p(e(be,2),:));

% Clear selection
in        = false(size(pm,1),1);
bcdata.in = in;

% Plot midpoints
plot(pe(bcdata.unassigned,1),pe(bcdata.unassigned,2),'k.', ...
     pe(bcdata.velocity,1)  ,pe(bcdata.velocity,2)  ,'b.', ...
     pe(bcdata.pressure,1)  ,pe(bcdata.pressure,2)  ,'g.', ...
     pe(bcdata.gradient,1)  ,pe(bcdata.gradient,2)  ,'y.', ...
     pm(in,1)               ,pm(in,2)               ,'r.');

set(fig,'UserData',bcdata); 
 
return


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function select(varargin)

% Select boundary midpoints using the mouse

% Get GUI data
fig    = gcf; 
ax     = gca;
bcdata = get(fig,'UserData');

% Boundary edge geometry
e  = bcdata.e;
be = bcdata.be;
p  = bcdata.p;
pe = bcdata.pe;
in = bcdata.in;
pm = 0.5*(p(e(be,1),:)+p(e(be,2),:));

% Plot midpoints
plot(pe(bcdata.unassigned,1),pe(bcdata.unassigned,2),'k.', ...
     pe(bcdata.velocity,1)  ,pe(bcdata.velocity,2)  ,'b.', ...
     pe(bcdata.pressure,1)  ,pe(bcdata.pressure,2)  ,'g.', ...
     pe(bcdata.gradient,1)  ,pe(bcdata.gradient,2)  ,'y.', ...
     pm(in,1)               ,pm(in,2)               ,'r.');

title('Right click to confirm') 
 
% Set mouse to "crosshair"
set(fig,'Pointer','crosshair');

while true
    
    % Wait for mouse click
    waitforbuttonpress
    
    % Grab type of mouse click
    btn = get(fig,'SelectionType');
    
    if strcmp(btn,'normal')
        % Draw selection box
        p1 = get(ax,'CurrentPoint');
        rbbox
        p2 = get(ax,'CurrentPoint');
        % xy co-ords within axis
        p1 = p1(1,1:2); p2 = p2(1,1:2);
        % Sorted (left, right, bottom, top)
        x1 = min(p1(1),p2(1)); x2 = max(p1(1),p2(1));
        y1 = min(p1(2),p2(2)); y2 = max(p1(2),p2(2));
        % Find nodes within selection
        in = xor((pm(:,1)>=x1&pm(:,1)<=x2&pm(:,2)>=y1&pm(:,2)<=y2),in);
        % Show selected
        plot(pe(bcdata.unassigned,1),pe(bcdata.unassigned,2),'k.', ...
             pe(bcdata.velocity,1)  ,pe(bcdata.velocity,2)  ,'b.', ...
             pe(bcdata.pressure,1)  ,pe(bcdata.pressure,2)  ,'g.', ...
             pe(bcdata.gradient,1)  ,pe(bcdata.gradient,2)  ,'y.', ...
             pm(in,1)               ,pm(in,2)               ,'r.');
    else
        break
    end

end
bcdata.in = in; title('')

% Pass selection as userdata
set(fig,'UserData',bcdata,'Pointer','arrow');

return


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function bc_type(varargin)

% Set the BC type and value

% Get GUI data from the "set bc" window
fig    = gcf;
bcdata = get(fig,'UserData');

% Boundary edge geometry
e  = bcdata.e;
be = bcdata.be;
p  = bcdata.p;
pe = bcdata.pe;
in = bcdata.in;
pm = 0.5*(p(e(be,1),:)+p(e(be,2),:));

if sum(in)==0
    errordlg('No edges selected.')
    return
end

% Get main GUI data
data = get(figure(1),'Userdata'); figure(fig);

% Prompt with listbox
[i,ok] = listdlg('PromptString' , 'BC type:'            , ...
                 'Name'         , 'Boundary Conditions' , ...
                 'SelectionMode', 'Single'              , ...
                 'ListString'   , {'Velocity','Outflow (extrapolated)','Outflow (fixed pressure)'});
             
if ok
    if i==1     % Velocity
        
        while true
            % Prompt for symmetry or wall
            [j,ok] = listdlg('PromptString' , 'BC type: (CTRL+click)', ...
                             'Name'         , 'Boundary Conditions'  , ...
                             'ListString'   , {'U','dU/dn = 0','V','dV/dn = 0'});

            if ~ok
                return
            end  
            if length(j)~=2 || (j(1)~=1)&&(j(1)~=2) || (j(2)~=3)&&(j(2)~=4)
                uiwait(errordlg('Must make selections for U and V','Error'));
            else
                break
            end
        end
        
        % BC type
        if j(1)==2, utype = 0; else utype = 1; end
        if j(2)==4, vtype = 0; else vtype = 1; end
        
        % Prompt for user input
        if (utype==1) && (vtype==1)
            value = inputdlg({'U velocity (m/s)','V velocity (m/s)'},'Velocity components',1,{'0','0'});
        elseif utype==1
            value = inputdlg('U velocity (m/s)','Velocity components',1,{'0'});
        elseif vtype==1
            value = inputdlg('V velocity (m/s)','Velocity components',1,{'0'});
        else
            value = ['0','0'];
        end
        
        % Convert to double
        if ~isempty(value)
            value = str2double(value);
            if (utype==1) && (vtype==0), value = [value,0]; end
            if (vtype==1) && (utype==0), value = [0,value]; end
            % Assign to main GUI data
            data.bc(be(in),1:6) = repmat([utype,value(1),vtype,value(2),0,0],sum(in),1);
        else
            return
        end
    else        % Pressure
        if i==2
            % Assign to main GUI data
            data.bc(be(in),1:6) = repmat([0,0,0,0,2,0],sum(in),1);      % Extrapolated BC
        else
            % Assign to main GUI data
            data.bc(be(in),1:6) = repmat([0,0,0,0,1,0],sum(in),1);      % Fixed pressure BC
        end
    end
end

% Re-evaluate
boundary     = false(size(e,1),1);
boundary(be) = true;
unassigned   = data.bc(:,1)==-1 & boundary;
velocity     = data.bc(:,1)== 1;
pressure     = data.bc(:,5) > 0;
gradient     = xor(data.bc(:,1),data.bc(:,3));

% Clear selection
in                = false(size(pm,1),1);
bcdata.in         = in;
bcdata.unassigned = unassigned;
bcdata.velocity   = velocity;
bcdata.pressure   = pressure;
bcdata.gradient   = gradient;

% Plot midpoints
hold off

plot(pe(bcdata.unassigned,1),pe(bcdata.unassigned,2),'k.', ...
     pe(bcdata.velocity,1)  ,pe(bcdata.velocity,2)  ,'b.', ...
     pe(bcdata.pressure,1)  ,pe(bcdata.pressure,2)  ,'g.', ...
     pe(bcdata.gradient,1)  ,pe(bcdata.gradient,2)  ,'y.', ...
     pm(in,1)               ,pm(in,2)               ,'r.'), axis equal, axis off, hold on

% Plot edges
patch('faces',e(unassigned,:),'vertices',data.mesh.p,'facecolor','none','edgecolor','k'); 
patch('faces',e(velocity,:)  ,'vertices',data.mesh.p,'facecolor','none','edgecolor','b'); 
patch('faces',e(pressure,:)  ,'vertices',data.mesh.p,'facecolor','none','edgecolor','g');  
patch('faces',e(gradient,:)  ,'vertices',data.mesh.p,'facecolor','none','edgecolor','y');  

% Plot arrows for velocity type
if any(velocity)
    quiver(pe(velocity,1),pe(velocity,2),data.bc(velocity,2),data.bc(velocity,4))
end
 
set(fig,'UserData',bcdata);

% Set main GUI data
set(figure(1),'UserData',data); figure(fig)

return


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function set_bc_tracer(varargin)

% Set the boundary conditions

data = get(figure(1),'UserData');

if isempty(data.mesh)
    errordlg('No mesh file loaded.','Error')
    return
end

set(figure, ...
          'Name'        ,'Boundary Conditions (tracer)', ...
          'DoubleBuffer','On'                          , ...
          'Units'       ,'Normalized');
      
axes('Units'   ,'Normalized', ...
     'Position',[0.25,0.1,0.7,0.8]);      
     
btnx = 0.1;
btny = 0.05;

% Buttons
b1 = uicontrol('Style','PushButton'           , ...
               'Units','Normalized'           , ...
               'Position',[0.05,0.3,btnx,btny], ...
               'String','Select'              , ...
               'Callback',@select);
           
b2 = uicontrol('Style','PushButton'           , ...
               'Units','Normalized'           , ...
               'Position',[0.05,0.1,btnx,btny], ...
               'String','Set'                 , ...
               'Callback',@bc_type_tracer);   
           
b3 = uicontrol('Style','PushButton'           , ...
               'Units','Normalized'           , ...
               'Position',[0.05,0.2,btnx,btny], ...
               'String','Clear'               , ...
               'Callback',@clear_sel);  
           
b4 = uicontrol('Style'   ,'PushButton'        , ...
               'Units'   ,'Normalized'        , ...
               'Position',[0.05,0.4,btnx,btny], ...
               'String'  ,'Help'              , ...
               'Callback',@help_bc);              
           
% Headers           
uicontrol('Style'          ,'Text'              , ...
          'Units'          ,'Normalized'        , ...
          'Position'       ,[0.025,0.8,0.2,0.05], ...
          'String'         ,'Black = Unassigned', ...
          'BackgroundColor',[0.8,0.8,0.8]);  
uicontrol('Style'          ,'Text'               , ...
          'Units'          ,'Normalized'         , ...
          'Position'       ,[0.025,0.75,0.2,0.05], ...
          'String'         ,'Blue = Value'       , ...
          'BackgroundColor',[0.8,0.8,0.8]);  
uicontrol('Style'          ,'Text'               , ...
          'Units'          ,'Normalized'         , ...
          'Position'       ,[0.025,0.7,0.2,0.05], ...
          'String'         ,'Yellow = Gradient'  , ...
          'BackgroundColor',[0.8,0.8,0.8]);  

% Boundary edge geometry
e  = data.mesh.e;
be = data.mesh.be;
p  = data.mesh.p;
pe = data.mesh.pe;
pm = 0.5*(p(e(be,1),:)+p(e(be,2),:));

boundary     = false(size(e,1),1);
pressure     = boundary;            % "Pressure" type doesn't exist for tracer. Set = false
boundary(be) = true;
unassigned   = data.bc(:,7)==-1 & boundary;
velocity     = data.bc(:,7)== 1;    % Re-use "velocity" as value so that the other
gradient     = data.bc(:,7)== 0;    % sub-functions will work...  

% Plot midpoints
plot(pe(unassigned,1),pe(unassigned,2),'k.', ...
     pe(velocity,1)  ,pe(velocity,2)  ,'b.', ...
     pe(gradient,1)  ,pe(gradient,2)  ,'y.'), axis equal, axis off, hold on