scf_celebic/ex3/seq/generate_mesh/ascii_write_mesh.m
dino.celebic 3882aee07a task8
2025-11-11 15:50:51 +01:00

49 lines
2.2 KiB
Matlab

function ascii_write_mesh( xc, ia, e, basename)
%
% Saves the 2D triangular mesh in the minimal way (only coordinates, vertex connectivity, minimal boundary edge info)
% in an ASCII file.
% Matlab indexing is stored (starts with 1).
%
% The output file format is compatible with Mesh_2d_3_matlab:Mesh_2d_3_matlab(std::string const &fname) in jacobi_oo_stl/geom.h
%
% IN:
% coordinates xc: [2][nnode]
% connectivity ia: [4][nelem] with t(4,:) are the subdomain numbers
% edges e: [7][nedges] boundary edges
% e([1,2],:) - start/end vertex of edge
% e([3,4],:) - start/end values
% e(5,:) - segment number
% e([6,7],:) - left/right subdomain
% basename: file name without extension
%
% Data have been generated via <https://de.mathworks.com/help/pde/ug/initmesh.html initmesh>.
%
fname = [basename, '.txt'];
nnode = int32(size(xc,2));
ndim = int32(size(xc,1));
nelem = int32(size(ia,2));
nvert_e = int32(3);
dlmwrite(fname,nnode,'delimiter','\t','precision',16) % number of nodes
dlmwrite(fname,ndim,'-append','delimiter','\t','precision',16) % space dimension
dlmwrite(fname,nelem,'-append','delimiter','\t','precision',16) % number of elements
dlmwrite(fname,nvert_e,'-append','delimiter','\t','precision',16) % number of vertices per element
% dlmwrite(fname,xc(:),'-append','delimiter','\t','precision',16) % coordinates
dlmwrite(fname,xc([1,2],:).','-append','delimiter','\t','precision',16) % coordinates
% no subdomain info transferred
tmp=int32(ia(1:3,:));
% dlmwrite(fname,tmp(:),'-append','delimiter','\t','precision',16) % connectivity in Matlab indexing
dlmwrite(fname,tmp(:,:).','-append','delimiter','\t','precision',16) % connectivity in Matlab indexing
% store only start and end point of boundary edges,
nbedges = size(e,2);
dlmwrite(fname,nbedges,'-append','delimiter','\t','precision',16) % number boundary edges
tmp=int32(e(1:2,:));
% dlmwrite(fname,tmp(:),'-append','delimiter','\t','precision',16) % boundary edges in Matlab indexing
dlmwrite(fname,tmp(:,:).','-append','delimiter','\t','precision',16) % boundary edges in Matlab indexing
end