home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Cream of the Crop 26
/
Cream of the Crop 26.iso
/
os2
/
octa209s.zip
/
octave-2.09
/
src
/
find.cc
< prev
next >
Wrap
C/C++ Source or Header
|
1996-11-03
|
4KB
|
202 lines
/*
Copyright (C) 1996 John W. Eaton
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 2, 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, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "defun-dld.h"
#include "error.h"
#include "gripes.h"
#include "help.h"
#include "oct-obj.h"
static octave_value_list
find_to_fortran_idx (const ColumnVector i_idx, const ColumnVector j_idx,
const octave_value& val, int nr, int nargout)
{
octave_value_list retval;
switch (nargout)
{
case 0:
case 1:
{
int count = i_idx.length ();
ColumnVector tmp (count);
for (int i = 0; i < count; i++)
tmp (i) = nr * (j_idx (i) - 1.0) + i_idx (i);
// If the original argument was a row vector, force a row
// vector of indices to be returned.
retval(0) = octave_value (tmp, (nr != 1));
}
break;
case 3:
retval(2) = val;
// Fall through!
case 2:
retval(1) = octave_value (j_idx, 1);
retval(0) = octave_value (i_idx, 1);
// If you want this to work more like Matlab, use
//
// retval(0) = octave_value (i_idx, (nr != 1));
//
// instead of the previous statement.
break;
default:
panic_impossible ();
break;
}
return retval;
}
static octave_value_list
find_nonzero_elem_idx (const Matrix& m, int nargout)
{
int count = 0;
int m_nr = m.rows ();
int m_nc = m.columns ();
int i, j;
for (j = 0; j < m_nc; j++)
for (i = 0; i < m_nr; i++)
if (m (i, j) != 0.0)
count++;
octave_value_list retval (((nargout == 0) ? 1 : nargout), Matrix ());
if (count == 0)
return retval;
ColumnVector i_idx (count);
ColumnVector j_idx (count);
ColumnVector v (count);
count = 0;
for (j = 0; j < m_nc; j++)
for (i = 0; i < m_nr; i++)
{
double d = m (i, j);
if (d != 0.0)
{
i_idx (count) = i + 1;
j_idx (count) = j + 1;
v (count) = d;
count++;
}
}
octave_value tmp (v, 1);
return find_to_fortran_idx (i_idx, j_idx, tmp, m_nr, nargout);
}
static octave_value_list
find_nonzero_elem_idx (const ComplexMatrix& m, int nargout)
{
int count = 0;
int m_nr = m.rows ();
int m_nc = m.columns ();
int i, j;
for (j = 0; j < m_nc; j++)
for (i = 0; i < m_nr; i++)
if (m (i, j) != 0.0)
count++;
octave_value_list retval (((nargout == 0) ? 1 : nargout), Matrix ());
if (count == 0)
return retval;
ColumnVector i_idx (count);
ColumnVector j_idx (count);
ComplexColumnVector v (count);
count = 0;
for (j = 0; j < m_nc; j++)
for (i = 0; i < m_nr; i++)
{
Complex c = m (i, j);
if (c != 0.0)
{
i_idx (count) = i + 1;
j_idx (count) = j + 1;
v (count) = c;
count++;
}
}
octave_value tmp (v, 1);
return find_to_fortran_idx (i_idx, j_idx, tmp, m_nr, nargout);
}
DEFUN_DLD (find, args, nargout,
"find (X) or [I, J, V] = find (X): Return indices of nonzero elements")
{
octave_value_list retval;
int nargin = args.length ();
if (nargin != 1 || nargout > 3)
{
print_usage ("find");
return retval;
}
octave_value arg = args(0);
if (arg.is_real_type ())
{
Matrix m = arg.matrix_value ();
if (! error_state)
retval = find_nonzero_elem_idx (m, nargout);
}
else if (arg.is_complex_type ())
{
ComplexMatrix m = arg.complex_matrix_value ();
if (! error_state)
retval = find_nonzero_elem_idx (m, nargout);
}
else
{
gripe_wrong_type_arg ("find", arg);
}
return retval;
}
/*
;;; Local Variables: ***
;;; mode: C++ ***
;;; End: ***
*/