view scripts/special-matrix/hilb.m @ 2311:2b5788792cad

[project @ 1996-07-11 20:18:38 by jwe]
author jwe
date Thu, 11 Jul 1996 20:18:38 +0000
parents 5cffc4b8de57
children 5ca126254d15
line wrap: on
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### 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.

## usage: hilb (n)
##
## Return the Hilbert matrix of order n.  The i, j element of a Hilbert
## matrix is defined as
##
##  H (i, j) = 1 / (i + j - 1);
##
## See also: hankel, vander, hadamard, invhilb, toeplitz

function retval = hilb (n)


  if (nargin != 1)
    usage ("hilb (n)");
  endif

  nmax = length (n);
  if (nmax == 1)
    retval = zeros (n);
    tmp = 1:n;
    for i = 1:n
      retval (i, :) = 1.0 ./ (tmp + (i - 1));
    endfor
  else
    error ("hilb: expecting scalar argument, found something else");
  endif

endfunction