I modified step-52 in following way Change this line
TimeStepping::EmbeddedExplicitRungeKutta<Vector<double>> embedded_explicit_runge_kutta(method, coarsen_param, refine_param, min_delta, max_delta, refine_tol, coarsen_tol); into the following three steps TimeStepping::EmbeddedExplicitRungeKutta<Vector<double>> embedded_explicit_runge_kutta; embedded_explicit_runge_kutta.initialize(method); embedded_explicit_runge_kutta.set_time_adaptation_parameters( coarsen_param, refine_param, min_delta, max_delta, refine_tol, coarsen_tol); I get this error $ ./step-52 Explicit methods: Forward Euler: error=1.00883 Third order Runge-Kutta: error=0.000227982 Fourth order Runge-Kutta: error=1.90541e-06 Implicit methods: Backward Euler: error=1.03428 Implicit Midpoint: error=0.00862702 Crank-Nicolson: error=0.00862675 SDIRK: error=0.0042349 Embedded explicit methods: -------------------------------------------------------- An error occurred in line <356> of file </Users/praveen/Applications/deal.II/9.3.1/include/deal.II/lac/vector.templates.h> in function void dealii::Vector<double>::sadd(const Number, const Number, const Vector<Number> &) [number = double] The violated condition was: size() == v.size() Additional information: Dimension 1089 not equal to 0. Stacktrace: ----------- #0 2 libdeal_II.g.9.3.1.dylib 0x00000001069035dc _ZN6dealii6VectorIdE4saddEddRKS1_ + 532: 2 libdeal_II.g.9.3.1.dylib 0x00000001069035dc _ZN6dealii6VectorIdE4saddEddRKS1_ #1 3 libdeal_II.g.9.3.1.dylib 0x0000000106ebb45c _ZN6dealii12TimeStepping26EmbeddedExplicitRungeKuttaINS_6VectorIdEEE14compute_stagesERKNSt3__18functionIFS3_dRKS3_EEEddS8_RNS5_6vectorIS3_NS5_9allocatorIS3_EEEE + 244: 3 libdeal_II.g.9.3.1.dylib 0x0000000106ebb45c _ZN6dealii12TimeStepping26EmbeddedExplicitRungeKuttaINS_6VectorIdEEE14compute_stagesERKNSt3__18functionIFS3_dRKS3_EEEddS8_RNS5_6vectorIS3_NS5_9allocatorIS3_EEEE #2 4 libdeal_II.g.9.3.1.dylib 0x0000000106ebb144 _ZN6dealii12TimeStepping26EmbeddedExplicitRungeKuttaINS_6VectorIdEEE20evolve_one_time_stepERKNSt3__18functionIFS3_dRKS3_EEEddRS3_ + 216: 4 libdeal_II.g.9.3.1.dylib 0x0000000106ebb144 _ZN6dealii12TimeStepping26EmbeddedExplicitRungeKuttaINS_6VectorIdEEE20evolve_one_time_stepERKNSt3__18functionIFS3_dRKS3_EEEddRS3_ #3 5 step-52 0x0000000102fdf28c _ZN6Step529Diffusion24embedded_explicit_methodEN6dealii12TimeStepping18runge_kutta_methodEjdd + 324: 5 step-52 0x0000000102fdf28c _ZN6Step529Diffusion24embedded_explicit_methodEN6dealii12TimeStepping18runge_kutta_methodEjdd #4 6 step-52 0x0000000102fdf6b4 _ZN6Step529Diffusion3runEv + 728: 6 step-52 0x0000000102fdf6b4 _ZN6Step529Diffusion3runEv #5 7 step-52 0x0000000102fdfee0 main + 72: 7 step-52 0x0000000102fdfee0 main #6 8 libdyld.dylib 0x00000001831a5430 start + 4: 8 libdyld.dylib 0x00000001831a5430 start -------------------------------------------------------- zsh: abort ./step-52 Thanks praveen -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to dealii+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/A23B08A1-6C42-42C1-807E-CAF36E638B7C%40gmail.com.