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Matlab read and write routines for YSMP format.

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falgout 2000-10-04 15:59:54 +00:00
parent c97fa21d0c
commit 3abbeb61c2
3 changed files with 110 additions and 0 deletions
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47
tools/manalyze.m Normal file
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function [nv,ia,ja,a] = manalyze(A);
%-----------------------------------------
%function [nv,ia,ja,a] = manalyze(A);
% Analyzes matrix A, yields ysmp format
%-----------------------------------------
% determine row/column indices of nonzero entries
% add to diagonal while determining indices to
% ensure that diagonal will be present even if 0
d = diag(A);
mn = min(d);
shf=mn+1;
[ja, I] = find(A'+shf*speye(size(A)));
t = find(A'+shf*speye(size(A)));
AA=A';
a=full(AA(t));
nv = size(A, 1);
na = size(a, 1);
% compute ia and put diagonal entry first on each row
ia = zeros(nv+1, 1);
ia(1) = 1;
for i = 1 : nv
k = ia(i);
while (k <= na)
if (I(k) ~= i)
break;
end
% swap diagonal entry with first entry
if (ja(k) == i)
tmp = a(ia(i));
a(ia(i)) = a(k);
a(k) = tmp;
tmp = ja(ia(i));
ja(ia(i)) = ja(k);
ja(k) = tmp;
end
k = k + 1;
end
ia(i+1) = k;
end

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tools/readysmp.m Normal file
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function [A,ia,ja,a] = readysmp(filename)
%-----------------------------------------------------------------------------
% [A] = readysmp('filename'):
% Reads from file 'filename' a matrix A in YSMP format.
%
% YSMP format:
% First line is 'nv' the number of rows in matrix. Integer.
%
% Next 'nv+1' lines are ia(1:nv+1). ia(j) points to the location
% in 'a' and 'ja' where the first entry for row 'j' lives. ia(nv+1)
% points to the element one greater than length(a). Integers.
%
% Next 'ia(nv+1)-1' lines contain 'ja' the list of non-zero columns.
% The numbers [ja(ia(j)):ja(ia(j+1)-1)] contain the nonzero columns in
% row 'j', with 'j', the diagonal column, listed first. That is,
% ja(ia(j))=j. Integers.
%
% Next 'ia(nv+1)-1' lines contain 'a' values.
% The numbers [a(ia(j)):a(ia(j+1)-1)] contain the nonzero values in
% row 'j', corresponding to columns [ja(ia(j)):ja(ia(j+1)-1)]. Reals.
%
%-----------------------------------------------------------------------------
fid=fopen(filename,'r');
nv = fscanf(fid,'%d',1); % number of variables (nv)
[ia, count] = fscanf(fid,'%d ',nv+1);
[ja, count] = fscanf(fid,'%d ',ia(nv+1)-1); % This is ja
[a, count]=fscanf(fid,'%le ',ia(nv+1)-1); % This is the matrix a
fclose(fid);
kz=zeros(length(ja),1);
p=1;
for j=1:nv,
plen = ia(j+1)-ia(j);
kz(p:p+plen-1)=j*ones(plen,1);
p=p+plen;
end
A = sparse(kz,ja,a);

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tools/writeysmp.m Normal file
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function [nv,ia,ja,a] = writeysmp(filename,A,nv,ia,ja,a)
% function [nv,ia,ja,a] = writeysmp(filename,A,nv,ia,ja,a)
%
% writes ysmp file in 'filename' (no qualifiers added,
% eg. not 'filename.ysmp')
%
% arguments nv, ia, ja, and a are optional.
%
if nargin < 6
[nv,ia,ja,a] = manalyze(A);
end;
outdat = [filename];
fid=fopen(outdat,'w');
fprintf(fid,'%d\n',nv); % number of variables (nv)
fprintf(fid,'%d\n',ia);
fprintf(fid,'%d\n',ja);
fprintf(fid,'%.15e\n',a);
fclose(fid);