DOC fix multiclass AUC formulas in user guide (#18559)

RamyaNP · web-flow · commit d304331b4503 · 2020-12-16T17:35:19.000+01:00
diff --git a/doc/modules/model_evaluation.rst b/doc/modules/model_evaluation.rst
@@ -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
