Tpetra::Vector errors

[tread7284]

@tpetra

I am trying to construct Tpetra::Vector from a Tpetra::Map, but the compiler errors suggest that no matching constructor exists for this operation. Additionally, you encountered an error with accessing vector elements using operator[], which isn't supported by Tpetra::Vector.

I am getting the following errors in my model:

OA_try/main.cpp: In function ‘int main(int, char**)’:
/home/t**/OA_try/main.cpp:62:33: error: no matching function for call to ‘Tpetra::Vector::Vector(Tpetra::Map<int, long long int, Tpetra::KokkosCompat::KokkosDeviceWrapperNodeKokkos::Serial >&)’
62 | Tpetra::Vector x(map); // The state vector [pH, CO2]

  |                                 ^

note: candidate expects 0 arguments, 1 provided
/home/t**/OA_try/main.cpp:67:36: error: no matching function for call to ‘Tpetra::Vector::Vector(Tpetra::Map<int, long long int, Tpetra::KokkosCompat::KokkosDeviceWrapperNodeKokkos::Serial >&)’
67 | Tpetra::Vector dxdt(map); // Vector to store the time derivative

Any advice on how to over come these issues with Tpetra, would be greatly appreciated!

[cgcgcg]

Tpetra::Vector is templated on scalar type, local and global ordinals and the node type. So you'd need to specify these. I think the constructor expects an RCP<const map_type>, not map_type. Maybe share how you are constructing the map?

[tread7284]

@cgcgcg I have attached the section of code below:

#include <Sacado.hpp> // For stochastic modeling (Sacado)
#include <Teuchos_RCP.hpp>
#include <Teuchos_GlobalMPISession.hpp>
#include <Tpetra_Core.hpp>
#include <Tpetra_Vector.hpp>
#include <Tpetra_Map.hpp>
#include
#include
#include // For random number generation

// Define the stochastic parameterized variable (using Sacado)
template
class OceanAcidificationModel {
public:
OceanAcidificationModel(double emission_mean, double emission_stddev)
: emission_mean_(emission_mean), emission_stddev_(emission_stddev) {}

// Stochastic CO2 emission model (e.g., normally distributed uncertainty)
T co2_emissions(T t) const {
    // Using standard C++ random number generation instead of Sacado's random function
    static std::default_random_engine generator;
    std::normal_distribution<T> distribution(emission_mean_, emission_stddev_);
    return distribution(generator);
}

// pH model (example of a simple stochastic ODE system)
void compute_rhs(const Tpetra::Vector<double>& x, Tpetra::Vector<double>& dxdt, double t) {
    // Example dynamics for ocean acidification
    // x[0] = pH, x[1] = CO2 concentration
    auto x_data = x.getData();  // Get mutable data access
    double co2 = x_data[1];
    double pH = x_data[0];

    // Simple dynamical system with a stochastic term for CO2 emissions
    auto dxdt_data = dxdt.getDataNonConst();  // Mutable access to dxdt data
    dxdt_data[0] = -0.1 * co2 + 0.02 * co2_emissions(t); // pH change
    dxdt_data[1] = -0.05 * co2 + 0.1 * pH; // CO2 concentration change
}

private:
double emission_mean_;
double emission_stddev_;
};

int main(int argc, char* argv[]) {
// Initialize Tpetra (serial mode, no MPI)
Tpetra::ScopeGuard tpetraScope(&argc, &argv); // Corrected constructor

// Define the model parameters (mean and std deviation for stochastic emissions)
double emission_mean = 1.0;  // Mean CO2 emissions
double emission_stddev = 0.2; // Std dev of CO2 emissions
OceanAcidificationModel<double> model(emission_mean, emission_stddev);

// Use the default communicator for serial execution
Teuchos::RCP<const Teuchos::Comm<int>> comm = Tpetra::getDefaultComm();

// Set up the initial conditions for the ocean acidification model
const int numGlobalEntries = 2; // 2 variables (pH, CO2 concentration)
Tpetra::Map<int> map(numGlobalEntries, 0, comm); // No MPI, so we just use the default communicator

// Corrected: Initialize the vector with proper constructor
Tpetra::Vector<double> x(map);  // The state vector [pH, CO2]
auto x_data = x.getDataNonConst();
x_data[0] = 8.1; // Initial pH value
x_data[1] = 300; // Initial CO2 concentration (ppm)

Tpetra::Vector<double> dxdt(map); // Vector to store the time derivative

// Define the time integration parameters
double start_time = 0.0;
double end_time = 100.0; // Simulate over 100 time steps
double dt = 1.0; // Time step size

// Time-stepping loop
for (double t = start_time; t <= end_time; t += dt) {
    model.compute_rhs(x, dxdt, t);

    // Integrate the system (Euler method for simplicity)
    x.update(1.0, dxdt, dt);  // x = x + dt * dxdt

    // Output the results
    if (static_cast<int>(t) % 10 == 0) {
        auto x_data = x.getData();
        std::cout << "Time: " << t << ", pH: " << x_data[0] << ", CO2: " << x_data[1] << std::endl;
    }
}

return 0;

}

Thank you for your quick response!

[cgcgcg]

auto map = Teuchos::rcp(new Tpetra::Map<int>(numGlobalEntries, 0, comm));
auto  x = Teuchos::rcp(new Tpetra::Vector<double>(map)); 

should do the trick. Tpetra might set default values for some of the template arguments, or they might get inferred from the map. Note that this changes the type of x from Tpetra::Vector<...> to Teuchos::RCP<Tpetra::Vector<...> >, i.e. to a pointer. For new code I would suggest to not use x.getDataNonConst but rather x.getLocalViewHost(Tpetra::Access::ReadWrite) as it will give you a Kokkos::View rather than a Teuchos object.

[tread7284]

@ Kokkos @cgcgcg

That fix the error I was getting in Teuchos, however I am now getting an error when I try to invoke the Kokkos::View.

This is the error, that I get:

OA_try/main.cpp:84:61: error: no match for call to ‘(Kokkos::View<const double**, Kokkos::LayoutLeft, Kokkos::Device<Kokkos::Serial, Kokkos::HostSpace>, Kokkos::Experimental::EmptyViewHooks, Kokkos::MemoryTraits<0> >) (int)’
   84 |             std::cout << "Time: " << t << ", pH: " << x_data(0) << ", CO2: " << x_data(1) << std::endl;

/OA_try/main.cpp:84:87: error: no match for call to ‘(Kokkos::View<const double**, Kokkos::LayoutLeft, Kokkos::Device<Kokkos::Serial, Kokkos::HostSpace>, Kokkos::Experimental::EmptyViewHooks, Kokkos::MemoryTraits<0> >) (int)’
   84 | Time: " << t << ", pH: " << x_data(0) << ", CO2: " << x_data(1) << std::endl;
      |        

I here is the updates sub module:

#include <Sacado.hpp>  // For stochastic modeling (Sacado)
#include <Teuchos_RCP.hpp>
#include <Teuchos_GlobalMPISession.hpp>
#include <Tpetra_Core.hpp>
#include <Tpetra_Vector.hpp>
#include <Tpetra_Map.hpp>
#include <iostream>
#include <cmath>
#include <random>  // For random number generation

// Define the stochastic parameterized variable (using Sacado)
template <typename T>
class OceanAcidificationModel {
public:
    OceanAcidificationModel(double emission_mean, double emission_stddev)
        : emission_mean_(emission_mean), emission_stddev_(emission_stddev) {}

    // Stochastic CO2 emission model (e.g., normally distributed uncertainty)
    T co2_emissions(T t) const {
        // Using standard C++ random number generation instead of Sacado's random function
        static std::default_random_engine generator;
        std::normal_distribution<T> distribution(emission_mean_, emission_stddev_);
        return distribution(generator);
    }

    // pH model (example of a simple stochastic ODE system)
    void compute_rhs(const Tpetra::Vector<double>& x, Tpetra::Vector<double>& dxdt, double t) {
        // Example dynamics for ocean acidification
        // x[0] = pH, x[1] = CO2 concentration
        auto x_data = x.getLocalViewHost(Tpetra::Access::ReadOnly);  // Get a const Kokkos::View of x data
        double co2 = x_data(1);
        double pH = x_data(0);

        // Simple dynamical system with a stochastic term for CO2 emissions
        auto dxdt_data = dxdt.getLocalViewHost(Tpetra::Access::ReadWrite);  // Get a mutable Kokkos::View for dxdt data
        dxdt_data(0) = -0.1 * co2 + 0.02 * co2_emissions(t); // pH change
        dxdt_data(1) = -0.05 * co2 + 0.1 * pH; // CO2 concentration change
    }

private:
    double emission_mean_;
    double emission_stddev_;
};

int main(int argc, char* argv[]) {
    // Initialize Tpetra (serial mode, no MPI)
    Tpetra::ScopeGuard tpetraScope(&argc, &argv);  // Corrected constructor

    // Define the model parameters (mean and std deviation for stochastic emissions)
    double emission_mean = 1.0;  // Mean CO2 emissions
    double emission_stddev = 0.2; // Std dev of CO2 emissions
    OceanAcidificationModel<double> model(emission_mean, emission_stddev);

    // Use the default communicator for serial execution
    Teuchos::RCP<const Teuchos::Comm<int>> comm = Tpetra::getDefaultComm();

    // Set up the initial conditions for the ocean acidification model
    const int numGlobalEntries = 2; // 2 variables (pH, CO2 concentration)
    Teuchos::RCP<Tpetra::Map<int>> map = Teuchos::rcp(new Tpetra::Map<int>(numGlobalEntries, 0, comm)); // Map with 2 entries

    // Corrected: Initialize the vector with proper constructor
    Teuchos::RCP<Tpetra::Vector<double>> x = Teuchos::rcp(new Tpetra::Vector<double>(map));  // The state vector [pH, CO2]
    auto x_data = x->getLocalViewHost(Tpetra::Access::ReadWrite);  // Mutable access to vector data
    x_data(0) = 8.1; // Initial pH value
    x_data(1) = 300; // Initial CO2 concentration (ppm)

    Teuchos::RCP<Tpetra::Vector<double>> dxdt = Teuchos::rcp(new Tpetra::Vector<double>(map)); // Vector to store the time derivative

    // Define the time integration parameters
    double start_time = 0.0;
    double end_time = 100.0; // Simulate over 100 time steps
    double dt = 1.0; // Time step size

    // Time-stepping loop
    for (double t = start_time; t <= end_time; t += dt) {
        model.compute_rhs(*x, *dxdt, t);

        // Integrate the system (Euler method for simplicity)
        x->update(1.0, *dxdt, dt);  // x = x + dt * dxdt

        // Output the results
        if (static_cast<int>(t) % 10 == 0) {
            auto x_data = x->getLocalViewHost(Tpetra::Access::ReadOnly);
            std::cout << "Time: " << t << ", pH: " << x_data(0) << ", CO2: " << x_data(1) << std::endl;
        }
    }

    return 0;
}

Thank you for your help in advance! Happy Holidays!

[cgcgcg]

Ah, yep. Tpetra::Vector derives from Tpetra::MultiVector and hence the local views are of size localDim x 1. You can either do use

x_data(0, 0)

or

auto x_data_1d = Kokkos::subview(x_data,Kokkos::ALL(), 0);
x_data_1d(0)

[tread7284]

@cgcgcg the first one fixed the issue! Thank you so much for your help!