/usr/share/octave/packages/strings-1.1.0/editdistance.m is in octave-strings 1.1.0-1build1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 | ## Copyright (C) 2006 Muthiah Annamalai <muthiah.annamalai@uta.edu>
##
## This program 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.
##
## This program 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
## this program; if not, see <http://www.gnu.org/licenses/>.
## -*- texinfo -*-
## @deftypefn {Function File} {[@var{dist},@var{L}] =} editdistance (@var{string1}, @var{string2}, @var{weights})
## Compute the Levenshtein edit distance between the strings @var{string1} and
## @var{string2}. This operation is symmetrical.
##
## The optional argument @var{weights} specifies weights for the
## deletion, matched, and insertion operations; by default it is set to
## +1, 0, +1 respectively, so that a least editdistance means a
## closer match between the two strings. This function implements
## the Levenshtein edit distance as presented in Wikipedia article,
## accessed Nov 2006. Also the levenshtein edit distance of a string
## with an empty string is defined to be its length.
##
## The default return value is @var{dist} the edit distance, and
## the other return value @var{L} is the distance matrix.
##
## @example
## @group
## editdistance('marry','marie')
## ##returns value +2 for the distance.
## @end group
## @end example
##
## @end deftypefn
function [dist, L] = editdistance (str1, str2, weights)
if(nargin < 2 || (nargin == 3 && length(weights) < 3) )
print_usage();
end
L1=length(str1)+1;
L2=length(str2)+1;
L=zeros(L1,L2);
if(nargin < 3)
g=+1;%insertion
m=+0;%match
d=+1;%deletion
else
g=weights(1);
m=weights(2);
d=weights(3);
end
L(:,1)=[0:L1-1]'*g;
L(1,:)=[0:L2-1]*g;
m4=0;
for idx=2:L1;
for idy=2:L2
if(str1(idx-1)==str2(idy-1))
score=m;
else
score=d;
end
m1=L(idx-1,idy-1) + score;
m2=L(idx-1,idy) + g;
m3=L(idx,idy-1) + g;
L(idx,idy)=min(m1,min(m2,m3));
end
end
dist=L(L1,L2);
endfunction
|