fix warnings

stuff/printing.hh

@@ -323,7 +323,6 @@ void printFunctionMinMax(Stream& stream, const Function& func)
 template <class Matrix, class Stream>
 void matrixToGnuplotStream(const Matrix& matrix, Stream& stream)
 {
-  assert(false);
   unsigned long nz = 0;
   for (size_t row = 0; row < matrix.rows(); ++row) {
     for (size_t col = 0; col < matrix.cols(); ++col) {