STK_PMISCLASS computes the (expected) probability of misclassification

 CALL: P = stk_pmisclass (U, Z_PRED)

    computes the probability of misclassification P with respect to the
    threshold U using the posterior means and variances contained in Z_PRED,
    where Z_PRED is a dataframe with column names 'mean' and 'var' (as
    returned by stk_predict).

 CALL: P = stk_pmisclass (U, Z1_PRED, K12, K22)

    computes the expected probability of misclassification P with respect to
    the threshold U at a set of locations X1, assuming that observations are
    made at another set of location X2, where:

     * Z1_PRED contains, as above, the posterior means and variances at X1;

     * K12 is the posterior covariance matrix between the values of the process
       at X1 and the observations (at X2);

     * K22 is the posterior covariance matrix of the observations.

 See also: stk_predict, stk_example_doe04