/*!
* @fn zscore
*
* @headerfile <seqan/statistics.h>
*
* @brief Computes the z-score index for a set of patterns w.r.t. a set of text
* strings and a MarkovModel.
*
* @signature TFloat zscore(W, X, M, algoTag);
*
* @param[in] W The StringSet of pattern strings.
* @param[in] X The StringSet of text strings.
* @param[in] M The MarkovModel object.
* @param[in] algoTag The algorithm to exploit to compute the number of
* occurrences of patterns in the text strings (see @link
* AhoCorasickPattern @endlink etc.).
*
* @return TFloat The z-score for W w.r.t. X and M, TFloat is the TFloat from
* the type of M.
*/