[3115] | 1 | function segments=findsegments(md,varargin)
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[1346] | 2 | %FINDSEGMENTS - build segments model field
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| 3 | %
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[3115] | 4 | % Optional inputs:
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[9728] | 5 | % 'mesh.elementconnectivity'
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[3115] | 6 | %
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[1346] | 7 | % Usage:
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[3115] | 8 | % segments=findsegments(md,varargin);
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[1346] | 9 |
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[3115] | 10 | %get options
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| 11 | options=pairoptions(varargin{:});
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| 12 |
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| 13 | %Get connectivity
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[9728] | 14 | mesh.elementconnectivity=getfieldvalue(options,'mesh.elementconnectivity',md.mesh.elementconnectivity);
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[3115] | 15 |
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| 16 | %Now, build the connectivity tables for this mesh if not correclty done
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[9728] | 17 | if size(md.mesh.elementconnectivity,1)~=md.mesh.numberofelements,
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| 18 | if exist(options,'mesh.elementconnectivity'),
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| 19 | error(' ''mesh.elementconnectivity'' option does not have thge right size.');
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[3115] | 20 | else
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[9733] | 21 | mesh.elementconnectivity=ElementConnectivity(md.mesh.elements,md.mesh.vertexconnectivity);
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[3115] | 22 | end
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[2082] | 23 | end
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[1346] | 24 |
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| 25 | %Recreate the segments
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[9728] | 26 | elementonboundary=double(mesh.elementconnectivity(:,3)==0);
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[1346] | 27 | pos=find(elementonboundary);
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| 28 | num_segments=length(pos);
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| 29 | segments=zeros(num_segments,3);
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[1347] | 30 | count=1;
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| 31 |
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[2612] | 32 | %loop over the segments
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[1346] | 33 | for i=1:num_segments,
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[2612] | 34 |
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| 35 | %get current element on boundary
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[1346] | 36 | el1=pos(i);
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[2612] | 37 |
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| 38 | %get elements connected to el1
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[9728] | 39 | els2=mesh.elementconnectivity(el1,find(mesh.elementconnectivity(el1,:)));
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[2612] | 40 |
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| 41 | %el1 is connected to 2 other elements
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[1347] | 42 | if length(els2)>1,
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[2612] | 43 |
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| 44 | %get nodes of el1
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[9733] | 45 | nods1=md.mesh.elements(el1,:);
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[2612] | 46 |
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| 47 | %find the common vertices to the two elements connected to el1 (1 or 2)
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[9733] | 48 | flag=intersect(md.mesh.elements(els2(1),:),md.mesh.elements(els2(2),:));
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[2612] | 49 |
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| 50 | %get the vertices on the boundary and build segment
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| 51 | nods1(find(ismember(nods1,flag)))=[];
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[1347] | 52 | segments(count,:)=[nods1 el1];
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[1346] | 53 |
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[8298] | 54 | %swap segment nodes if necessary
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[9733] | 55 | ord1=find(nods1(1)==md.mesh.elements(el1,:));
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| 56 | ord2=find(nods1(2)==md.mesh.elements(el1,:));
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[1347] | 57 | if ( (ord1==1 & ord2==2) | (ord1==2 & ord2==3) | (ord1==3 & ord2==1) ),
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| 58 | temp=segments(count,1);
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| 59 | segments(count,1)=segments(count,2);
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| 60 | segments(count,2)=temp;
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| 61 | end
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| 62 | segments(count,1:2)=fliplr(segments(count,1:2));
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| 63 | count=count+1;
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[2612] | 64 |
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| 65 | %el1 is connected to only one element
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[1347] | 66 | else
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[2612] | 67 | %get nodes of el1
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[9733] | 68 | nods1=md.mesh.elements(el1,:);
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[2612] | 69 |
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| 70 | %find the vertex the el1 to not share with els2
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[9733] | 71 | flag=setdiff(nods1,md.mesh.elements(els2,:));
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[2612] | 72 |
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[1347] | 73 | for j=1:3,
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| 74 | nods=nods1; nods(j)=[];
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| 75 | if any(ismember(flag,nods)),
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[2612] | 76 |
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[1347] | 77 | segments(count,:)=[nods el1];
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[2612] | 78 |
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[8298] | 79 | %swap segment nodes if necessary
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[9733] | 80 | ord1=find(nods(1)==md.mesh.elements(el1,:));
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| 81 | ord2=find(nods(2)==md.mesh.elements(el1,:));
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[1347] | 82 | if ( (ord1==1 & ord2==2) | (ord1==2 & ord2==3) | (ord1==3 & ord2==1) ),
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| 83 | temp=segments(count,1);
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| 84 | segments(count,1)=segments(count,2);
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| 85 | segments(count,2)=temp;
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| 86 | end
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| 87 | segments(count,1:2)=fliplr(segments(count,1:2));
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| 88 | count=count+1;
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| 89 | end
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| 90 | end
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[1346] | 91 | end
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| 92 | end
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