icefront_maker

PURPOSE ^

ICEFRONT_MAKER - ???

SYNOPSIS ^

function ind=icefront_maker(index,x,y,node_on_icefront,element_on_boundary);

DESCRIPTION ^

ICEFRONT_MAKER - ???

   This program takes element_on_boundary and node_on_icefront 
   x and  y and index and makes an ordered icefront with it,
   turning counter clockwise.

   Usage:
      ind=icefront_maker(index,x,y,node_on_icefront,element_on_boundary);

CROSS-REFERENCE INFORMATION ^

This function calls: This function is called by:

SOURCE CODE ^

0001 function ind=icefront_maker(index,x,y,node_on_icefront,element_on_boundary);
0002 %ICEFRONT_MAKER - ???
0003 %
0004 %   This program takes element_on_boundary and node_on_icefront
0005 %   x and  y and index and makes an ordered icefront with it,
0006 %   turning counter clockwise.
0007 %
0008 %   Usage:
0009 %      ind=icefront_maker(index,x,y,node_on_icefront,element_on_boundary);
0010 
0011 pos=find(node_on_icefront);
0012 pos2=find(x(pos)==max(x(pos)));
0013 xa=x(pos(pos2));
0014 ya=y(pos(pos2));
0015 
0016 temp=node_on_icefront;
0017 temp(pos(pos2))=0;
0018 
0019 pos=find(temp);
0020 pos2=find(x(pos)==max(x(pos)));
0021 xb=x(pos(pos2));
0022 yb=y(pos(pos2));
0023 
0024 
0025 
0026 plot(xa,ya,'r*')
0027 plot(xb,yb,'r*')
0028 
0029 
0030 n00=find(x==xa & y==ya);
0031 n10=find(x==xb & y==yb);
0032 n1=n10;
0033 n0=n00;
0034 cont=[n0 n1];
0035 
0036    
0037 while (n1~=n00),
0038    
0039    els=find(index(:,1)==n1 | index(:,2)==n1 | index(:,3)==n1);
0040    possible_nodes=zeros(2*length(els),1);
0041    for n=1:length(els),
0042    other_pos=find(index(els(n),:)~=n1);
0043    possible_nodes(2*n-1,:)= index(els(n),other_pos(1));
0044    possible_nodes(2*n,:)=index(els(n),other_pos(2));
0045     end
0046 potential_node=possible_nodes(1);
0047 
0048 n0n1=[x(n1)-x(n0)
0049    y(n1)-y(n0)];
0050 n0n1_unit=n0n1/norm(n0n1);
0051 ny=flipud(n0n1_unit);
0052 ny(1)=-ny(1);
0053 possible_angles=zeros(length(possible_nodes),1);
0054 
0055 for n=1:length(possible_nodes),
0056    if (possible_nodes(n)~=n0),
0057         u=[x(possible_nodes(n))-x(n1)
0058           y(possible_nodes(n))-y(n1)];
0059           ux=sum(u.*n0n1_unit);
0060           uy=sum((u-ux*n0n1_unit).*ny);
0061          possible_angles(n)=atan2(uy,ux);
0062       else
0063          possible_angles(n)=NaN;
0064    end
0065 end
0066 pos=find(possible_angles==min(possible_angles));
0067 potential_node=possible_nodes(pos(1));
0068 
0069 cont=[cont
0070    [n1 potential_node]];
0071 n0=n1;
0072 n1=potential_node;
0073 end
0074 
0075 ind=cont(2:length(cont),1);
0076 
0077

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