| SOM Toolbox | Online documentation | http://www.cis.hut.fi/projects/somtoolbox/ |
[sig,cm,truex,truey] = som_dreval(sR,D,sigmea,inds1,inds2,andor)
SOM_DREVAL Evaluate the significance of the given descriptive rule.
[sig,Cm,truex,truey] = som_dreval(cR,D,sigmea,[inds1],[inds2],[andor])
sR (struct) a rule struct, or an array of rule structs
D (matrix) the data, of size [dlen x nr]
sigmea (string) significance measure ('accuracy','accuracyI','mutuconf'),
see definitions below
[inds1] (vector) indeces belonging to the group
(by default: the whole data set)
[inds2] (vector) indeces belonging to the contrast group
(by default: the rest of the data set)
[andor] (string) 'and' or 'or': which conjunction operator to use
to join the rules for each variable
sig (scalar) significance of the rule
cm (vector) length 4, vectorized confusion matrix ([a,c,b,d]: see below)
truex (vector) binary vector indicating for each item in the
group whether it was true or not
truey (vector) binary vector indicating for each item in the
contrast group whether it was true or not
Descriptive rule significance is measured as the match between the
given groups (inds1 = G1, inds2 = G2) and the rule being true or false.
G1 G2
--------------- accuracy = (a+d) / (a+b+c+d)
true | a | b |
|-------------- mutuconf = a*a / ((a+b)(a+c))
false | c | d |
--------------- accuracyI = a / (a+b+c)
See also SOM_DRSIGNIF, SOM_DRMAKE.