[linalg.algs.blas2.gemv] Move example to avoid forward reference

Author: jensmaurer

source/numerics.tex

@@ -13664,12 +13664,6 @@
   matrix_vector_product(scaled(3.0, A), x, y);
 }
 
-// y = 3.0 * A * x + 2.0 * y
-void scaled_matvec_2(mdspan<double, extents<size_t, num_rows, num_cols>> A,
-  mdspan<double, extents<size_t, num_cols>> x, mdspan<double, extents<size_t, num_rows>> y) {
-  matrix_vector_product(scaled(3.0, A), x, scaled(2.0, y), y);
-}
-
 // z = 7.0 times the transpose of A, times y
 void scaled_transposed_matvec(mdspan<double, extents<size_t, num_rows, num_cols>> A,
   mdspan<double, extents<size_t, num_rows>> y, mdspan<double, extents<size_t, num_cols>> z) {
@@ -13700,6 +13694,16 @@
 \tcode{z} may alias \tcode{y}.
 \end{itemdescr}
 
+\begin{example}
+\begin{codeblock}
+// y = 3.0 * A * x + 2.0 * y
+void scaled_matvec_2(mdspan<double, extents<size_t, num_rows, num_cols>> A,
+  mdspan<double, extents<size_t, num_cols>> x, mdspan<double, extents<size_t, num_rows>> y) {
+  matrix_vector_product(scaled(3.0, A), x, scaled(2.0, y), y);
+}
+\end{codeblock}
+\end{example}
+
 \rSec3[linalg.algs.blas2.symv]{Symmetric matrix-vector product}
 
 \begin{note}