DOC typo in linear_model.rst
@@ -369,7 +369,7 @@ Mathematically, it consists of a linear model trained with a mixed
:math:`\ell_1` :math:`\ell_2`-norm for regularization.
The objective function to minimize is:
-.. math:: \min_{w} { \frac{1}{2n_{\text{samples}}} ||X W - Y||_{\text{Fro}} ^ 2 + \alpha ||W||_{21}}
+.. math:: \min_{W} { \frac{1}{2n_{\text{samples}}} ||X W - Y||_{\text{Fro}} ^ 2 + \alpha ||W||_{21}}
where :math:`\text{Fro}` indicates the Frobenius norm
