Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / dataframe-0.9.1 / @dataframe / inv.m

diff --git a/octave_packages/dataframe-0.9.1/@dataframe/inv.m b/octave_packages/dataframe-0.9.1/@dataframe/inv.m
new file mode 100644 (file)
index 0000000..7f135cc
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+++ b/octave_packages/dataframe-0.9.1/@dataframe/inv.m
@@ -0,0 +1,52 @@
+function [resu, rcond] = inv(df);
+
+  %# function [x, rcond] = inv(df)
+  %# Overloaded function computing the inverse of a dataframe. To
+  %# succeed, the dataframe must be convertible to an square array. Row
+  %# and column meta-information are exchanged.  
+
+  %% Copyright (C) 2009-2012 Pascal Dupuis <Pascal.Dupuis@uclouvain.be>
+  %%
+  %% 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, 51 Franklin Street -
+  %% Fifth Floor, Boston, MA 02110-1301, USA.
+  
+  %#
+  %# $Id: inv.m 9585 2012-02-05 15:32:46Z cdemills $
+  %#
+
+  if (length(df._cnt) > 2 || (df._cnt(1) != df._cnt(2))),
+    error("Dataframe is not square");
+  endif
+
+  %# quick and dirty conversion
+  [dummy, rcond] = inv(horzcat(df._data{:}));
+
+  resu = df_allmeta(df);
+  
+  [resu._name{2}, resu._name{1}] = deal(resu._name{1}, resu._name{2});
+  [resu._over{2}, resu._over{1}] = deal(resu._over{1}, resu._over{2});
+  if (isempty(resu._name{2})),
+    resu._name{2} = cellstr(repmat('_', resu._cnt(2), 1));
+    resu._over{2} = ones(1, resu._cnt(2));
+  endif
+  for indi = resu._cnt(1):-1:1,
+    resu._data{indi} = dummy(:, indi);
+  endfor
+  resu._type(:) = class(dummy);
+  
+endfunction