Throw an exception if buffer size and convolution weigths do not match

include/gram_savitzky_golay/gram_savitzky_golay.h

@@ -158,7 +158,12 @@ struct GRAM_SAVITZKY_GOLAY_DLLAPI SavitzkyGolayFilter
   template<typename ContainerT>
   typename ContainerT::value_type filter(const ContainerT & v) const
   {
-    assert(v.size() == weights_.size() && v.size() > 0);
+    if(v.size() != weights_.size() || v.size() < 1)
+    {
+      throw std::runtime_error("The size of v (" + std::to_string(v.size()) + ") and the convolution weights ("
+                               + std::to_string(weights_.size())
+                               + ") must be the same. Make sure that 2*m+1 = v.size()");
+    }
     using T = typename ContainerT::value_type;
     T res = weights_[0] * v[0];
     for(size_t i = 1; i < v.size(); ++i)

tests/test_gram_savitzky_golay.cpp

@@ -167,3 +167,25 @@ BOOST_AUTO_TEST_CASE(TestPolynomialDerivative)
   BOOST_REQUIRE_CLOSE(result_order1, expected_result_order1, 10e-8);
   BOOST_REQUIRE_CLOSE(result_order2, expected_result_order2, 10e-8);
 }
+
+// Test derivation on a known polynomial function
+BOOST_AUTO_TEST_CASE(TestWrongWindowSize)
+{
+  auto vec = std::vector<double>(300, 0);
+  BOOST_REQUIRE_EQUAL(vec.size(), 300);
+
+  // Window size is 2*m+1
+  const size_t m = 151;
+  // Polynomial Order
+  const size_t n = 6;
+  // Initial Point Smoothing (ie evaluate polynomial at first point in the window)
+  // Points are defined in range [-m;m]
+  const size_t t = m;
+  // Derivation order? 0: no derivation, 1: first derivative, 2: second derivative...
+  const int d = 0;
+
+  // Real-time filter (filtering at latest data point)
+  gram_sg::SavitzkyGolayFilter filter(m, t, n, d);
+  // Filter some data
+  BOOST_REQUIRE_THROW(filter.filter(vec), std::runtime_error);
+}