
A command that creates a Similarity from every selected Confusion.
The Average procedure averages:
similarity_{ij}= similarity_{ji} = (confusion_{ij} + confusion_{ji}) / 2 
The Houtgast procedure as described in the paper by Klein, Plomp & Pols (1970), expresses similarity between stimuli i and j by the number of times that stimulus i and j have resulted in the same response, summated over all response categories.
We use the following formula to calculate the Houtgast dissimilarities:
similarity_{ij} = ∑_{k=1..numberOfColumns} min (confusion_{ik}, confusion_{jk}) 
which is equivalent to the formula in the Klein et al. paper:
similarity_{ij} = ∑_{k=1..numberOfColumns} (confusion_{ik} + confusion_{jk} – confusion_{ik} – confusion_{jk}) 
© djmw, April 7, 2004