Template instantiation with Armadillo and boost::numeric::odeint - c++

Question

I am trying to combine boost::numeric::odeint with an implementation of the System class of my own (see System.hpp).
A (template) System object is used within a BatchFilter class method, like so:
# BatchFilter.cpp
# template <typename state_type> BatchFilter class {...}
System<state_type> dynamics(this -> args,
N_true,
this -> true_dynamics_fun );
typedef boost::numeric::odeint::runge_kutta_cash_karp54< state_type > error_stepper_type;
auto stepper = boost::numeric::odeint::make_controlled<error_stepper_type>( 1.0e-13 , 1.0e-16 );
auto tbegin = T_obs.begin();
auto tend = T_obs.end();
boost::numeric::odeint::integrate_times(stepper, dynamics, X0_true_copy, tbegin, tend,0.1,
Observer::push_back_state(this -> true_state_history));
BatchFilter is a template derived class which I am explicitly instantiating at the bottom of BatchFilter.cpp. The two explicit instantiations are
template class BatchFilter< arma::vec >;
template class BatchFilter< arma::vec::fixed<2> >;
The Base class is also explicitly instantiated. I must use arma::vec::fixed<2> since using arma::vec within odeint causes a runtime crash as the state will not have the proper size.
What does not work?
The instantiation with arma::vec::fixed<2> fails while the one with arma::vec succeeds. The compiler complains about an illegal binding:
cannot bind non-const lvalue reference of type'arma::Col<double>::fixed<2>&' to an rvalue of type'arma::Col<double>::fixed<2>' sys( x , m_dxdt.m_v ,t );
What puzzles me is that everything works fine when the explicit instantiation of BatchFilter< arma::vec > succeeds while BatchFilter< arma::vec::fixed<2> > fails.
Any insight as to what is going on?
[ 3%] Building CXX object CMakeFiles/ASPEN.dir/source/BatchFilter.cpp.o
In file included from /usr/local/include/boost/numeric/odeint.hpp:35:0,
from /Users/bbercovici/GDrive/CUBoulder/Research/code/ASPEN_gui_less/lib/include/Filter.hpp:5,
from /Users/bbercovici/GDrive/CUBoulder/Research/code/ASPEN_gui_less/lib/include/BatchFilter.hpp:5,
from /Users/bbercovici/GDrive/CUBoulder/Research/code/ASPEN_gui_less/lib/source/BatchFilter.cpp:1:
/usr/local/include/boost/numeric/odeint/stepper/controlled_runge_kutta.hpp: In instantiation of 'boost::numeric::odeint::controlled_step_result boost::numeric::odeint::controlled_runge_kutta<ErrorStepper, ErrorChecker, StepAdjuster, Resizer, boost::numeric::odeint::explicit_error_stepper_tag>::try_step_v1(System, StateInOut&, boost::numeric::odeint::controlled_runge_kutta<ErrorStepper, ErrorChecker, StepAdjuster, Resizer, boost::numeric::odeint::explicit_error_stepper_tag>::time_type&, boost::numeric::odeint::controlled_runge_kutta<ErrorStepper, ErrorChecker, StepAdjuster, Resizer, boost::numeric::odeint::explicit_error_stepper_tag>::time_type&) [with System = System<arma::Col<double>::fixed<2>, arma::Mat<double> >; StateInOut = arma::Col<double>; ErrorStepper = boost::numeric::odeint::runge_kutta_cash_karp54<arma::Col<double> >; ErrorChecker = boost::numeric::odeint::default_error_checker<double, boost::numeric::odeint::range_algebra, boost::numeric::odeint::default_operations>; StepAdjuster = boost::numeric::odeint::default_step_adjuster<double, double>; Resizer = boost::numeric::odeint::initially_resizer; boost::numeric::odeint::controlled_runge_kutta<ErrorStepper, ErrorChecker, StepAdjuster, Resizer, boost::numeric::odeint::explicit_error_stepper_tag>::time_type = double]':
/usr/local/include/boost/numeric/odeint/stepper/controlled_runge_kutta.hpp:283:27: required from 'boost::numeric::odeint::controlled_step_result boost::numeric::odeint::controlled_runge_kutta<ErrorStepper, ErrorChecker, StepAdjuster, Resizer, boost::numeric::odeint::explicit_error_stepper_tag>::try_step(System, StateInOut&, boost::numeric::odeint::controlled_runge_kutta<ErrorStepper, ErrorChecker, StepAdjuster, Resizer, boost::numeric::odeint::explicit_error_stepper_tag>::time_type&, boost::numeric::odeint::controlled_runge_kutta<ErrorStepper, ErrorChecker, StepAdjuster, Resizer, boost::numeric::odeint::explicit_error_stepper_tag>::time_type&) [with System = System<arma::Col<double>::fixed<2>, arma::Mat<double> >; StateInOut = arma::Col<double>; ErrorStepper = boost::numeric::odeint::runge_kutta_cash_karp54<arma::Col<double> >; ErrorChecker = boost::numeric::odeint::default_error_checker<double, boost::numeric::odeint::range_algebra, boost::numeric::odeint::default_operations>; StepAdjuster = boost::numeric::odeint::default_step_adjuster<double, double>; Resizer = boost::numeric::odeint::initially_resizer; boost::numeric::odeint::controlled_runge_kutta<ErrorStepper, ErrorChecker, StepAdjuster, Resizer, boost::numeric::odeint::explicit_error_stepper_tag>::time_type = double]'
/usr/local/include/boost/numeric/odeint/integrate/detail/integrate_times.hpp:101:81: required from 'size_t boost::numeric::odeint::detail::integrate_times(Stepper, System, State&, TimeIterator, TimeIterator, Time, Observer, boost::numeric::odeint::controlled_stepper_tag) [with Stepper = boost::numeric::odeint::controlled_runge_kutta<boost::numeric::odeint::runge_kutta_cash_karp54<arma::Col<double> >, boost::numeric::odeint::default_error_checker<double, boost::numeric::odeint::range_algebra, boost::numeric::odeint::default_operations>, boost::numeric::odeint::default_step_adjuster<double, double>, boost::numeric::odeint::initially_resizer, boost::numeric::odeint::explicit_error_stepper_tag>; System = System<arma::Col<double>::fixed<2>, arma::Mat<double> >; State = arma::Col<double>; TimeIterator = __gnu_cxx::__normal_iterator<const double*, std::vector<double> >; Time = double; Observer = Observer::push_back_state<arma::Col<double> >; size_t = long unsigned int]'
/usr/local/include/boost/numeric/odeint/integrate/integrate_times.hpp:129:35: required from 'size_t boost::numeric::odeint::integrate_times(Stepper, System, State&, TimeIterator, TimeIterator, Time, Observer) [with Stepper = boost::numeric::odeint::controlled_runge_kutta<boost::numeric::odeint::runge_kutta_cash_karp54<arma::Col<double> >, boost::numeric::odeint::default_error_checker<double, boost::numeric::odeint::range_algebra, boost::numeric::odeint::default_operations>, boost::numeric::odeint::default_step_adjuster<double, double>, boost::numeric::odeint::initially_resizer, boost::numeric::odeint::explicit_error_stepper_tag>; System = System<arma::Col<double>::fixed<2>, arma::Mat<double> >; State = arma::Col<double>; TimeIterator = __gnu_cxx::__normal_iterator<const double*, std::vector<double> >; Time = double; Observer = Observer::push_back_state<arma::Col<double> >; size_t = long unsigned int]'
/Users/bbercovici/GDrive/CUBoulder/Research/code/ASPEN_gui_less/lib/source/BatchFilter.cpp:231:42: required from void BatchFilter<state_type>::compute_reference_state_history(const std::vector<double>&, std::vector<_RealType>&, std::vector<arma::Mat<double> >&) [with state_type = arma::Col<double>::fixed<2>]'
/Users/bbercovici/GDrive/CUBoulder/Research/code/ASPEN_gui_less/lib/source/BatchFilter.cpp:327:16: required from here
/usr/local/include/boost/numeric/odeint/stepper/controlled_runge_kutta.hpp:481:12: error: no match for call to '(boost::numeric::odeint::unwrap_reference<System<arma::Col<double>::fixed<2>, arma::Mat<double> > >::type {aka System<arma::Col<double>::fixed<2>, arma::Mat<double> >}) (arma::Col<double>&, arma::Col<double>&, boost::numeric::odeint::controlled_runge_kutta<boost::numeric::odeint::runge_kutta_cash_karp54<arma::Col<double> >, boost::numeric::odeint::default_error_checker<double, boost::numeric::odeint::range_algebra, boost::numeric::odeint::default_operations>, boost::numeric::odeint::default_step_adjuster<double, double>, boost::numeric::odeint::initially_resizer, boost::numeric::odeint::explicit_error_stepper_tag>::time_type&)'
sys( x , m_dxdt.m_v ,t );
~~~^~~~~~~~~~~~~~~~~~~~~
In file included from /Users/bbercovici/GDrive/CUBoulder/Research/code/ASPEN_gui_less/lib/include/Filter.hpp:6:0,
from /Users/bbercovici/GDrive/CUBoulder/Research/code/ASPEN_gui_less/lib/include/BatchFilter.hpp:5,
from /Users/bbercovici/GDrive/CUBoulder/Research/code/ASPEN_gui_less/lib/source/BatchFilter.cpp:1:
/Users/bbercovici/GDrive/CUBoulder/Research/code/ASPEN_gui_less/lib/include/System.hpp:32:7: note: candidate: void System<state_type, jacobian_type>::operator()(const state_type&, state_type&, double) [with state_type = arma::Col<double>::fixed<2>; jacobian_type = arma::Mat<double>] <near match>
void operator() (const state_type & x , state_type & dxdt , const double t ){
^~~~~~~~
/Users/bbercovici/GDrive/CUBoulder/Research/code/ASPEN_gui_less/lib/include/System.hpp:32:7: note: conversion of argument 2 would be ill-formed:
In file included from /usr/local/include/boost/numeric/odeint.hpp:35:0,
from /Users/bbercovici/GDrive/CUBoulder/Research/code/ASPEN_gui_less/lib/include/Filter.hpp:5,
from /Users/bbercovici/GDrive/CUBoulder/Research/code/ASPEN_gui_less/lib/include/BatchFilter.hpp:5,
from /Users/bbercovici/GDrive/CUBoulder/Research/code/ASPEN_gui_less/lib/source/BatchFilter.cpp:1:
/usr/local/include/boost/numeric/odeint/stepper/controlled_runge_kutta.hpp:481:25: error: cannot bind non-const lvalue reference of type 'arma::Col<double>::fixed<2>&' to an rvalue of type 'arma::Col<double>::fixed<2>'
sys( x , m_dxdt.m_v ,t );
~~~~~~~^~~
In file included from /usr/local/include/armadillo:568:0,
from /Users/bbercovici/GDrive/CUBoulder/Research/code/ASPEN_gui_less/lib/include/BatchFilter.hpp:4,
from /Users/bbercovici/GDrive/CUBoulder/Research/code/ASPEN_gui_less/lib/source/BatchFilter.cpp:1:
/usr/local/include/armadillo_bits/Col_meat.hpp:1145:1: note: after user-defined conversion: arma::Col<eT>::fixed<fixed_n_elem>::fixed(const arma::Base<eT, T1>&) [with T1 = arma::Mat<double>; long long unsigned int fixed_n_elem = 2; eT = double]
Col<eT>::fixed<fixed_n_elem>::fixed(const Base<eT,T1>& A)
^~~~~~~
make[2]: *** [CMakeFiles/ASPEN.dir/source/BatchFilter.cpp.o] Error 1
make[1]: *** [CMakeFiles/ASPEN.dir/all] Error 2
make: *** [all] Error 2
For reference, System.hpp is down here:
# System.hpp
template <typename state_type,typename jacobian_type = arma::mat> class System {
public:
System(const Args & args,
unsigned int N_est,
state_type (*estimate_dynamics_fun)(double, const state_type & , const Args & args) ,
jacobian_type (*jacobian_estimate_dynamics_fun)(double, const state_type & , const Args & args),
unsigned int N_true = 0,
state_type (*true_dynamics_fun)(double, const state_type & , const Args & args) = nullptr)
: N_est(N_est), N_true(N_true){
this -> estimate_dynamics_fun = estimate_dynamics_fun;
this -> true_dynamics_fun = estimate_dynamics_fun;
this -> jacobian_estimate_dynamics_fun = jacobian_estimate_dynamics_fun;
this -> args = args;
}
System(const Args & args,
unsigned int N_true,
state_type (*true_dynamics_fun)(double, const state_type & , const Args & args))
: N_est(0), N_true(N_true){
this -> true_dynamics_fun = true_dynamics_fun;
this -> args = args;
}
void operator() (const state_type & x , state_type & dxdt , const double t ){
if (this -> true_dynamics_fun != nullptr){
dxdt.rows(this -> N_est + this -> N_est * this -> N_est,
this -> N_est + this -> N_est * this -> N_est + this -> N_true - 1) = this -> true_dynamics_fun(t,
x.rows(this -> N_est + this -> N_est * this -> N_est,
this -> N_est + this -> N_est * this -> N_est + this -> N_true - 1),args);
}
if (this -> estimate_dynamics_fun != nullptr){
arma::mat Phi = arma::reshape(x.rows(this -> N_est,
this -> N_est + this -> N_est * this -> N_est - 1), this -> N_est, this -> N_est );
arma::mat A = this -> jacobian_estimate_dynamics_fun(t,x.rows(0,this -> N_est - 1),this -> args);
dxdt.rows(0,this -> N_est - 1) = this -> estimate_dynamics_fun(t,x.rows(0,this -> N_est - 1),this -> args);
dxdt.rows(this -> N_est,
this -> N_est + this -> N_est * this -> N_est - 1) = arma::vectorise(A * Phi);
}
}
protected:
const unsigned int N_est;
const unsigned int N_true;
state_type (*estimate_dynamics_fun)(double, const state_type & , const Args & args) = nullptr;
state_type (*true_dynamics_fun)(double, const state_type & , const Args & args) = nullptr;
jacobian_type (*jacobian_estimate_dynamics_fun)(double, const state_type & , const Args & args) = nullptr;
Args args;
};

Answer 1

I found a way around the resizing issue here:
https://reformatcode.com/code/c/armadillo-conflicts-with-boost-odeint-odeint-resizes-the-state-vector-to-zero-during-integration
The solution consists in extending boost:numeric::odeint with the following adapters that handle automatic resizing of the arma::vec for safe use with odeint
#include <armadillo>
namespace boost { namespace numeric { namespace odeint {
template <>
struct is_resizeable<arma::vec>
{
typedef boost::true_type type;
const static bool value = type::value;
};
template <>
struct same_size_impl<arma::vec, arma::vec>
{
static bool same_size(const arma::vec & x, const arma::vec& y)
{
return x.n_rows == y.n_rows;
}
};
template<>
struct resize_impl<arma::vec, arma::vec>
{
static void resize(arma::vec &v1, const arma::vec & v2)
{
v1.resize(v2.n_rows,1);
}
};
} } } // namespace boost::numeric::odeint