DOC fix multiclass AUC formulas in user guide
@@ -1423,7 +1423,7 @@ uniformly:
.. math::
- \frac{2}{c(c-1)}\sum_{j=1}^{c}\sum_{k > j}^c (\text{AUC}(j | k) +
+ \frac{1}{c(c-1)}\sum_{j=1}^{c}\sum_{k > j}^c (\text{AUC}(j | k) +
\text{AUC}(k | j))
where :math:`c` is the number of classes and :math:`\text{AUC}(j | k)` is the
@@ -1438,7 +1438,7 @@ prevalence:
.. math::
- \frac{2}{c(c-1)}\sum_{j=1}^{c}\sum_{k > j}^c p(j \cup k)(
+ \frac{1}{c(c-1)}\sum_{j=1}^{c}\sum_{k > j}^c p(j \cup k)(
\text{AUC}(j | k) + \text{AUC}(k | j))
where :math:`c` is the number of classes. This algorithm is used by setting
