|Log-Likelihood measure is computed as||
Log-Likelihood = 2 * [n11 * log(n11/m11) + n12 * log(n12/m12) +
n21 * log(n21/m21) + n22 * log(n22/m22)]
|Total Mutual Information||
TMI = (1/npp)*[n11 * log(n11/m11)/log 2 + n12 * log(n12/m12)/log 2 +
n21 * log(n21/m21)/log 2 + n22 * log(n22/m22)/log 2]
|Pointwise Mutual Information||PMI = log (n11/m11)/log 2|
|Poisson Stirling Measures||PS = n11*(log (n11/m11)-1)|
getValues() - This method calls the computeMarginalTotals(), computeObservedValues() and the computeExpectedValues() methods to compute the observed and expected values. It checks these values for any errors that might cause the Loglikelihood, TMI & PMI measures to fail. INPUT PARAMS : $count_values .. Reference of an hash containing
the count values computed by the
RETURN VALUES : 1/undef ..returns 1 to indicate success
and an undefined(NULL) value to indicate
computePMI() - Computes the pmi of a given observed and expected value pair. INPUT PARAMS : $n ..Observed value
$m ..Expected value
RETURN VALUES : log(n/m) ..the log of the ratio of
observed value to expected
Ted Pedersen, University of Minnesota Duluth
Satanjeev Banerjee, Carnegie Mellon University
Amruta Purandare, University of Pittsburgh
Bridget Thomson-McInnes, University of Minnesota Twin Cities
Saiyam Kohli, University of Minnesota Duluth
Last updated: $Id: MI.pm,v 1.27 2008/03/26 17:18:26 tpederse Exp $
Copyright (C) 2000-2006, Ted Pedersen, Satanjeev Banerjee, Amruta Purandare, Bridget Thomson-McInnes and Saiyam Kohli
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 2 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, write to
The Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
Note: a copy of the GNU General Public License is available on the web at <http://www.gnu.org/licenses/gpl.txt> and is included in this distribution as GPL.txt.
|perl v5.20.3||TEXT::NSP::MEASURES::2D::MI (3)||2008-03-26|