sortmesh

 [no,el,fc]=sortmesh(origin,node,elem,face)

 sort nodes and elements in a mesh so that the indexed
 nodes and elements are closer to each order
 (this may reduce cache-miss in a calculation)

 author: Qianqian Fang, <q.fang at neu.edu>
 date: 2010/05/06

 input:
    origin: sorting all nodes and elements with the distance and
            angles wrt this location, if origin=[], it will be 
            node(1,:)
    node: list of nodes
    elem: list of elements (each row are indices of nodes of each element)
    ecol: list of columns in elem to participate sorting
    face: list of surface triangles (this can be omitted)
    fcol: list of columns in face to participate sorting

 output:
    no: node coordinates in the sorted order
    el: the element list in the sorted order
    fc: the surface triangle list in the sorted order (can be ignored)
    nodemap: the new node mapping order, no=node(nodemap,:)

 -- this function is part of iso2mesh toolbox (http://iso2mesh.sf.net)

0001 function [no,el,fc,nodemap]=sortmesh(origin,node,elem,ecol,face,fcol)
0002 %
0003 % [no,el,fc]=sortmesh(origin,node,elem,face)
0004 %
0005 % sort nodes and elements in a mesh so that the indexed
0006 % nodes and elements are closer to each order
0007 % (this may reduce cache-miss in a calculation)
0008 %
0009 % author: Qianqian Fang, <q.fang at neu.edu>
0010 % date: 2010/05/06
0011 %
0012 % input:
0013 %    origin: sorting all nodes and elements with the distance and
0014 %            angles wrt this location, if origin=[], it will be
0015 %            node(1,:)
0016 %    node: list of nodes
0017 %    elem: list of elements (each row are indices of nodes of each element)
0018 %    ecol: list of columns in elem to participate sorting
0019 %    face: list of surface triangles (this can be omitted)
0020 %    fcol: list of columns in face to participate sorting
0021 %
0022 % output:
0023 %    no: node coordinates in the sorted order
0024 %    el: the element list in the sorted order
0025 %    fc: the surface triangle list in the sorted order (can be ignored)
0026 %    nodemap: the new node mapping order, no=node(nodemap,:)
0027 %
0028 % -- this function is part of iso2mesh toolbox (http://iso2mesh.sf.net)
0029 %
0030 
0031 if(isempty(origin))
0032    origin=node(1,:);
0033 end
0034 sdist=node-repmat(origin,size(node,1),1);
0035 [theta,phi,R]=cart2sph(sdist(:,1),sdist(:,2),sdist(:,3));
0036 sdist=[R,phi,theta];
0037 [nval,nodemap]=sortrows(sdist);
0038 no=node(nodemap,:);
0039 
0040 [nval,nidx]=sortrows(nodemap);
0041 el=elem;
0042 if(nargin<4)
0043    ecol=1:size(elem,2);
0044 end
0045 el(:,ecol)=sort(nidx(elem(:,ecol)),2);
0046 el=sortrows(el,ecol);
0047 
0048 if(nargin>=5 && nargout==3)
0049   if(nargin<6)
0050      fcol=1:size(face,2);
0051   end
0052   fc=face;
0053   fc(:,fcol)=sort(nidx(face(:,fcol)),2);
0054   fc=sortrows(fc,fcol);
0055 end