Improve docstring

1 files changed, 12 insertions, 0 deletions

diff --git a/polymatrix/polymatrix/mixins.py b/polymatrix/polymatrix/mixins.py
index c7a1b00..7313a8e 100644
--- a/polymatrix/polymatrix/mixins.py
+++ b/polymatrix/polymatrix/mixins.py
@@ -378,6 +378,18 @@ class PolyMatrixAsAffineExpressionMixin(
         Evaluate the affine expression
         :math:`p(x) = \sum_{\alpha \in \mathcal{E}\langle x \rangle_d} A_\alpha x^\alpha`
         at a given :math:`x`.
+
+        The code performs the evaluation by computing the matrix product
+
+        .. math::
+            p(x) = \begin{bmatrix}
+                A_{\alpha_1} & A_{\alpha_2} & \cdots & A_{\alpha_N}
+            \end{bmatrix} (B(x) \otimes I_m)
+            \quad
+
+        where :math:`B(x)` contains the monomials and :math:`m` is the number
+        of columns of each :math:`A_\alpha`. See also :py:meth:`monomials_eval`
+        and :py:meth:`monomials_eval_all`.
         """
 
         # Get the number of variables involved