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comparison m-toolbox/classes/@matrix/inv.m @ 0:f0afece42f48

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Import.
author Daniele Nicolodi <nicolodi@science.unitn.it>
date Wed, 23 Nov 2011 19:22:13 +0100
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-1:000000000000 0:f0afece42f48
1 % INV evaluates the inverse for matrix object.
2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
3 %
4 % DESCRIPTION: INV evaluates the inverse for matrix objects.
5 %
6 % CALL: obj = inv(mat)
7 % obj = mat.inv()
8 %
9 % <a href="matlab:utils.helper.displayMethodInfo('matrix', 'inv')">Parameters Description</a>
10 %
11 % VERSION: $Id: inv.m,v 1.10 2011/04/08 08:56:31 hewitson Exp $
12 %
13 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
14
15 function varargout = inv(varargin)
16
17 % Check if this is a call for parameters
18 if utils.helper.isinfocall(varargin{:})
19 varargout{1} = getInfo(varargin{3});
20 return
21 end
22
23 % Check if the method was called by another method
24 callerIsMethod = utils.helper.callerIsMethod;
25
26 % Collect input variable names
27 in_names = cell(size(varargin));
28 for ii = 1:nargin,in_names{ii} = inputname(ii);end
29
30 % Collect all matrices and plists
31 [as, matrix_invars, rest] = utils.helper.collect_objects(varargin(:), 'matrix', in_names);
32 [pl, pl_invars, rest] = utils.helper.collect_objects(varargin(:), 'plist', in_names);
33
34 % Decide on a deep copy or a modify
35 bs = copy(as, nargout);
36
37 % Combine input plists and default plist
38 usepl = parse(pl, getDefaultPlist());
39
40 % do dimension check
41 [rw,cl] = size(bs.objs);
42 if rw ~= cl
43 error('### Matrix must be square');
44 end
45
46 % get the determinant
47 DA = det(bs);
48
49 % build cofactor matrix
50 C = copy(bs,1);
51 for ii = 1:rw % raw index
52 for jj = 1:cl % column index
53 % ij Minor of A
54 MA = copy(bs,1);
55 MA.objs(ii,:) = [];
56 MA.objs(:,jj) = [];
57 % cofactor
58 C.objs(ii,jj) = det(MA).*((-1)^(ii+jj));
59 end
60 end
61 % get the transpose of cofactors matrix
62 CT = transpose(C);
63 % do inverse
64 bs = CT./matrix(DA);
65
66 if ~callerIsMethod
67 % set name
68 bs.setName(sprintf('inv(%s)', in_names{1}));
69
70 % Add history
71 bs.addHistory(getInfo('None'), usepl, [matrix_invars(:)], [as(:).hist]);
72 end
73
74 varargout{1} = bs;
75
76 end
77
78 %--------------------------------------------------------------------------
79 % Get Info Object
80 %--------------------------------------------------------------------------
81 function ii = getInfo(varargin)
82
83 if nargin == 1 && strcmpi(varargin{1}, 'None')
84 sets = {};
85 pl = [];
86 else
87 sets = {'Default'};
88 pl = getDefaultPlist;
89 end
90 % Build info object
91 ii = minfo(mfilename, 'matrix', 'ltpda', utils.const.categories.op, '$Id: inv.m,v 1.10 2011/04/08 08:56:31 hewitson Exp $', sets, pl);
92 end
93
94 %--------------------------------------------------------------------------
95 % Get Default Plist
96 %--------------------------------------------------------------------------
97
98 function plout = getDefaultPlist()
99 persistent pl;
100 if ~exist('pl', 'var') || isempty(pl)
101 pl = buildplist();
102 end
103 plout = pl;
104 end
105
106 function pl = buildplist()
107 pl = plist.EMPTY_PLIST;
108 end
109