subscript fix

Author: rasbt

docs/equations/pymle-equations.pdf

@@ -139,16 +139,16 @@ \section{Artificial neurons -- a brief glimpse into the early history of machine
 
 \[
 \mathbf{w} = \begin{bmatrix}
-    w^{(1)}  \\
-    w^{(2)}  \\
+    w_{1}  \\
+    w_{2}  \\
     \vdots  \\
-    w^{(m)}
-\end{bmatrix},
-\mathbf{w} = \begin{bmatrix}
-    x^{(1)}  \\
-    x^{(2)}  \\
+    w_{m}
+\end{bmatrix}, \quad
+\mathbf{x} = \begin{bmatrix}
+    x_{1}  \\
+    x_{2}  \\
     \vdots  \\
-    x^{(m)}
+    x_{m}
 \end{bmatrix}.
 \]