diff --git a/doc/snippets/MatrixBase_isIdentity.cpp b/doc/snippets/MatrixBase_isIdentity.cpp
new file mode 100644
index 0000000..17b756c
--- /dev/null
+++ b/doc/snippets/MatrixBase_isIdentity.cpp
@@ -0,0 +1,5 @@
+Matrix3d m = Matrix3d::Identity();
+m(0,2) = 1e-4;
+cout << "Here's the matrix m:" << endl << m << endl;
+cout << "m.isIdentity() returns: " << m.isIdentity() << endl;
+cout << "m.isIdentity(1e-3) returns: " << m.isIdentity(1e-3) << endl;