update packages

[CreaPhase.git] / octave_packages / m / sparse / spconvert.m

diff --git a/octave_packages/m/sparse/spconvert.m b/octave_packages/m/sparse/spconvert.m
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+## Copyright (C) 2004-2012 David Bateman and Andy Adler
+##
+## This file is part of Octave.
+##
+## Octave is free software; you can redistribute it and/or modify it
+## under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 3 of the License, or (at
+## your option) any later version.
+##
+## Octave is distributed in the hope that it will be useful, but
+## WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+## General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with Octave; see the file COPYING.  If not, see
+## <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {@var{x} =} spconvert (@var{m})
+## This function converts for a simple sparse matrix format easily
+## produced by other programs into Octave's internal sparse format.  The
+## input @var{x} is either a 3 or 4 column real matrix, containing
+## the row, column, real and imaginary parts of the elements of the
+## sparse matrix.  An element with a zero real and imaginary part can
+## be used to force a particular matrix size.
+## @end deftypefn
+
+function s = spconvert (m)
+
+  if (issparse (m))
+    s = m;
+  else
+    sz = size (m);
+    if (nargin != 1 || ! ismatrix (m) || ! isreal (m)
+        || length (sz) != 2 || (sz(2) != 3 && sz(2) != 4))
+      error ("spconvert: argument must be sparse or real matrix with 3 or 4 columns");
+    elseif (sz(2) == 3)
+      s = sparse (m(:,1), m(:,2), m(:,3));
+    else
+      s = sparse (m(:,1), m(:,2), m(:,3) + 1i*m(:,4));
+    endif
+  endif
+
+endfunction
+
+
+%!test
+%! i = [1; 3; 5];
+%! j = [2; 4; 6];
+%! v = [7; 8; 9];
+%! s = spconvert ([i, j, v]);
+%! assert (issparse (s));
+%! [fi, fj, fv] = find (s);
+%! assert (isequal (i, fi) && isequal (j, fj) && isequal (v, fv));
+%! s = spconvert ([i, j, v, j]);
+%! [fi, fj, fv] = find (s);
+%! assert (isequal (i, fi) && isequal (j, fj) && isequal (complex (v, j), fv));
+%! assert (size (spconvert ([1, 1, 3; 5, 15, 0])), [5, 15]);
+
+%% Test input validation
+%!error spconvert ()
+%!error spconvert (1, 2)
+%!error spconvert ({[1 2 3]})
+%!error spconvert ([1 2])
+%!error spconvert ([1 2 3i])
+%!error spconvert ([1 2 3 4 5])