rework Identity API: no longer restricted to square matrices
diff --git a/test/linearstructure.cpp b/test/linearstructure.cpp
index c90488d..682315c 100644
--- a/test/linearstructure.cpp
+++ b/test/linearstructure.cpp
@@ -46,7 +46,7 @@
              m3(rows, cols),
              mzero = MatrixType::zero(rows, cols),
              identity = Matrix<Scalar, MatrixType::Traits::RowsAtCompileTime, MatrixType::Traits::RowsAtCompileTime>
-                              ::identity(rows),
+                              ::identity(rows, rows),
              square = Matrix<Scalar, MatrixType::Traits::RowsAtCompileTime, MatrixType::Traits::RowsAtCompileTime>
                               ::random(rows, rows);
   VectorType v1 = VectorType::random(rows),