File: spconvert.m

package info (click to toggle)
octave 9.4.0-1
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid, trixie
  • size: 144,300 kB
  • sloc: cpp: 332,784; ansic: 77,239; fortran: 20,963; objc: 9,396; sh: 8,213; yacc: 4,925; lex: 4,389; perl: 1,544; java: 1,366; awk: 1,259; makefile: 648; xml: 189
file content (80 lines) | stat: -rw-r--r-- 2,600 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
########################################################################
##
## Copyright (C) 2004-2024 The Octave Project Developers
##
## See the file COPYRIGHT.md in the top-level directory of this
## distribution or <https://octave.org/copyright/>.
##
## 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
## <https://www.gnu.org/licenses/>.
##
########################################################################

## -*- texinfo -*-
## @deftypefn {} {@var{x} =} spconvert (@var{m})
## Convert a simple sparse matrix format easily generated by other programs
## into Octave's internal sparse format.
##
## The input @var{m} 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.
## @seealso{sparse}
## @end deftypefn

function s = spconvert (m)

  if (nargin < 1)
    print_usage ();
  endif

  if (issparse (m))
    s = m;
  else
    sz = size (m);
    if (! 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 <Invalid call> spconvert ()
%!error spconvert ({[1 2 3]})
%!error spconvert ([1 2])
%!error spconvert ([1 2 3i])
%!error spconvert ([1 2 3 4 5])