hypre/tools/read_matrix.m

129 lines
3.8 KiB
Matlab

% function [A,symmetric,dim,grid,stencil] = read_matrix(fid);
% --------------------------------------------------------------------------
% Driver to create an output matrix file that one_to_many can then read to
% create several input matrix files for the parallel smg code to use.
% --------------------------------------------------------------------------
% Input:
% fid - output file unit number (fid = fopen( ... ))
% Output:
% A - matrix object in full or sparse format
% symmetric - flag for output file indicating if matrix is symmetric
% =1 if symmetric, =0 if nonsymmetric
% dim - dimension of the underlying grid (2 or 3)
% grid - column or row vector of length 6 containing grid
% extents. grid must be loaded as
%
% grid(1) = imin; grid(2) = jmin; grid(3) = kmin;
% grid(4) = imax; grid(5) = jmax; grid(6) = kmax;
%
% where imin <= i <= imax, jmin <= j <= jmax, and
% kmin <= k <= kmax. Note that imin = jmin = kmin = 1
% must always be enforced since matlab matrices must have
% positive indices
% stencil - array of size (stencil_size,3) where stencil_size is
% the number of elements in the stencil
%
% Original Version: 12-17-97
% Author: pnb
% --------------------------------------------------------------------------
%
function [A,symmetric,dim,grid,stencil] = read_matrix(fid);
% --------------------------------------------------------------
% Read in the matrix Symmetric, Grid and Stencil information.
% --------------------------------------------------------------
s = fscanf(fid, '%s',1);
% read symmetric info
s = fscanf(fid,'%s',1);
symmetric = fscanf(fid,'%d',1);
% read constant-coefficient info
s = fscanf(fid,'%s',1);
constcoeff = fscanf(fid,'%d',1);
% read grid info
s = fscanf(fid, '%s',1);
dim = fscanf(fid, '%d', 1);
d = fscanf(fid, '%d', 1);
s = fscanf(fid,'%s',1);
s = fscanf(fid,'%1s',1);
imin = fscanf(fid,'%d',1);
s = fscanf(fid,'%1s',1);
jmin = fscanf(fid,'%d',1);
s = fscanf(fid,'%1s',1);
kmin = fscanf(fid,'%d',1);
s = fscanf(fid,'%1s',1);
s = fscanf(fid,'%1s',1);
s = fscanf(fid,'%1s',1);
imax = fscanf(fid,'%d',1);
s = fscanf(fid,'%1s',1);
jmax = fscanf(fid,'%d',1);
s = fscanf(fid,'%1s',1);
kmax = fscanf(fid,'%d',1);
s = fscanf(fid,'%1s',1);
nx = imax - imin + 1;
ny = jmax - jmin + 1;
nz = kmax - kmin + 1;
grid = zeros(6,1)
imin
jmin
kmin
grid(1,1) = imin; grid(2,1) = jmin; grid(3,1) = kmin;
grid(4,1) = imax; grid(5,1) = jmax; grid(6,1) = kmax;
% read stencil info
s = fscanf(fid,'%s',1);
stencil_size = fscanf(fid,'%d',1);
stencil = zeros(stencil_size,3);
for i = 1:stencil_size,
s = fscanf(fid,'%s',1);
stencil(i,1) = fscanf(fid,'%d',1);
stencil(i,2) = fscanf(fid,'%d',1);
stencil(i,3) = fscanf(fid,'%d',1);
end
% read matrix data values
s = fscanf(fid, '%s',1);
A = spalloc(nx*ny*nz,nx*ny*nz, stencil_size*nx*ny*nz);
for kz = 1:nz,
for jy = 1:ny,
for ix = 1:nx,
for es = 1:stencil_size;
s = fscanf(fid,'%s',1);
s = fscanf(fid,'%1s',1);
i = fscanf(fid,'%d',1) + 1;
s = fscanf(fid,'%1s',1);
j = fscanf(fid,'%d',1) + 1;
s = fscanf(fid,'%1s',1);
k = fscanf(fid,'%d',1) + 1;
s = fscanf(fid,'%1s',1);
e = fscanf(fid,'%d',1) + 1;
s = fscanf(fid,'%1s',1);
data = fscanf(fid,'%e',1);
l = i + (j-1)*nx + (k-1)*ny*nx;
m = i+stencil(e,1) + (j+stencil(e,2)-1)*nx + ...
(k+stencil(e,3)-1)*ny*nx;
if ((i+stencil(e,1) > 0) & (j+stencil(e,2) > 0) & ...
(k+stencil(e,3) > 0) & ...
(i+stencil(e,1) <= nx) & (j+stencil(e,2) <= ny) & ...
(k+stencil(e,3) <= nz)) ...
A(l,m) = data;
end
end
end
end
end
if (symmetric == 1)
D = spdiags(A,0); B = A + A'; B = spdiags(D,0,B);
A = B;
end
% Close input file
fclose(fid);