add_sponge_nodes

 Add a set of sponge nodes comprising a single sponge layer to Mesh structure  

 [Mobj] = add_sponge_nodes(Mobj)

 DESCRIPTION:
    Select using ginput the set of nodes comprising a sponge layer

 INPUT
    Mobj = Matlab mesh object
    SpongeName = Name of the Sponge Layer
    SpongeRadius = Radius of influence of the Sponge Layer 
    SpongeCoeff  = Sponge damping coefficient

 OUTPUT:
    Mobj = Matlab mesh object with an additional sponge nodelist

 EXAMPLE USAGE
    Mobj = add_sponge_nodes(Mobj,'Sponge1',10000,.0001)

 Author(s):  
    Geoff Cowles (University of Massachusetts Dartmouth)

 Note:
    Uses ginput2 which allows zooming before selecting points and displays
    clicked points realtime

 Revision history
   
==============================================================================

0001 function [Mobj]  = add_sponge_nodes(Mobj,SpongeName,SpongeRadius,SpongeCoeff)
0002 
0003 % Add a set of sponge nodes comprising a single sponge layer to Mesh structure
0004 %
0005 % [Mobj] = add_sponge_nodes(Mobj)
0006 %
0007 % DESCRIPTION:
0008 %    Select using ginput the set of nodes comprising a sponge layer
0009 %
0010 % INPUT
0011 %    Mobj = Matlab mesh object
0012 %    SpongeName = Name of the Sponge Layer
0013 %    SpongeRadius = Radius of influence of the Sponge Layer
0014 %    SpongeCoeff  = Sponge damping coefficient
0015 %
0016 % OUTPUT:
0017 %    Mobj = Matlab mesh object with an additional sponge nodelist
0018 %
0019 % EXAMPLE USAGE
0020 %    Mobj = add_sponge_nodes(Mobj,'Sponge1',10000,.0001)
0021 %
0022 % Author(s):
0023 %    Geoff Cowles (University of Massachusetts Dartmouth)
0024 %
0025 % Note:
0026 %    Uses ginput2 which allows zooming before selecting points and displays
0027 %    clicked points realtime
0028 %
0029 % Revision history
0030 %
0031 %==============================================================================
0032 subname = 'add_sponge_nodes';
0033 fprintf('\n')
0034 fprintf(['begin : ' subname '\n'])
0035 
0036 
0037 %------------------------------------------------------------------------------
0038 % Plot the mesh
0039 %------------------------------------------------------------------------------
0040 
0041 if(lower(Mobj.nativeCoords(1:3)) == 'car')
0042     x = Mobj.x;
0043     y = Mobj.y;
0044 else
0045     x = Mobj.lon;
0046     y = Mobj.lat;
0047 end;
0048 
0049 figure
0050 patch('Vertices',[x,y],'Faces',Mobj.tri,...
0051         'Cdata',Mobj.h,'edgecolor','k','facecolor','interp');
0052 axis('equal','tight')
0053 hold on;
0054 
0055 % use ginput2 (which allows zooming and plots points as they are clicked) to let
0056 % user select the boundary points
0057 [xselect] = ginput2(true,'k+')
0058 
0059 
0060 npts = size(xselect,1);
0061 
0062 if(npts == 0)
0063     fprintf('you didn''t select any points')
0064     fprintf(['end   : ' subname '\n'])
0065     return
0066 end;
0067 fprintf('you selected %d points\n',npts)
0068 
0069 % snap to the closest vertices
0070 for i=1:npts
0071     [ipt(i),dist] = find_nearest_pt(xselect(i,1),xselect(i,2),Mobj);
0072 end;
0073 
0074 % replot domain with snapped vertices
0075 plot(x(ipt),y(ipt),'ro');
0076 
0077 % add to mesh object
0078 Mobj.nSponge = Mobj.nSponge + 1;
0079 Mobj.nSpongeNodes(Mobj.nSponge) = npts;
0080 Mobj.sponge_nodes(Mobj.nSponge,1:npts) = ipt;
0081 Mobj.sponge_name{Mobj.nSponge} = SpongeName;
0082 Mobj.sponge_rad(Mobj.nSponge) = SpongeRadius;
0083 Mobj.sponge_fac(Mobj.nSponge) = SpongeCoeff;
0084 
0085 
0086 fprintf(['end   : ' subname '\n'])
0087