[bugfix] complete default initialization (#28)

include/fcarouge/internal/kalman.hpp

@@ -109,22 +109,18 @@ struct kalman {
   //! @{
 
   //! @brief The state estimate vector x.
-  state x{};
+  state x{ 0 * Identity<state>()() };
 
   //! @brief The estimate uncertainty, covariance matrix P.
   //!
   //! @details The estimate uncertainty, covariance is also known as Σ.
   estimate_uncertainty p{ Identity<estimate_uncertainty>()() };
 
+  process_uncertainty q{ 0 * Identity<process_uncertainty>()() };
+  output_uncertainty r{ 0 * Identity<output_uncertainty>()() };
   output_model h{ Identity<output_model>()() };
-
-  output_uncertainty r{ Identity<output_uncertainty>()() };
-
   state_transition f{ Identity<state_transition>()() };
-
-  process_uncertainty q{};
-
-  input_control g{};
+  input_control g{ Identity<input_control>()() };
 
   //! @}
 

sample/dog_position1d.cpp

@@ -31,7 +31,7 @@ namespace
 //! Gaussian.
 //!
 //! @example dog_position1d.cpp
-[[maybe_unused]] auto dog_position{ [] {
+[[maybe_unused]] auto dog_position1d{ [] {
   using kalman = kalman<double>;
   kalman k;
 

test/test.cpp → test/initialization.cpp

@@ -36,19 +36,29 @@ OTHER DEALINGS IN THE SOFTWARE.
 
 For more information, please refer to <https://unlicense.org> */
 
+#include "fcarouge/kalman.hpp"
+
 #include <cassert>
 
 namespace fcarouge::test
 {
 namespace
 {
-//! @test Demonstrate the code.
-[[maybe_unused]] constexpr auto test = [] {
-  static_assert(true, "Compile-time check.");
-  assert(true && "Run-time check.");
+//! @test Verify default values are initialized.
+[[maybe_unused]] auto defaults{ [] {
+  using kalman = kalman<double>;
+  kalman k;
+
+  assert(0 == k.x() && "Origin state.");
+  assert(1 == k.p());
+  assert(0 == k.q() && "No process noise by default.");
+  assert(0 == k.r() && "No observation noise by default.");
+  assert(1 == k.f() && "");
+  assert(1 == k.h() && "");
+  assert(1 == k.g() && "");
 
   return 0;
-}();
+}() };
 
 } // namespace
 } // namespace fcarouge::test