CyRK.nb

Submodules

CyRK.nb.dop_coefficients module

CyRK.nb.nb_storage module

class CyRK.nb.nb_storage.WrapNBRKResult(success, message, size, num_dy, num_y, error_code, y, t)

Bases: tuple

error_code

Alias for field number 5

message

Alias for field number 1

num_dy

Alias for field number 3

num_y

Alias for field number 4

size

Alias for field number 2

success

Alias for field number 0

t

Alias for field number 7

y

Alias for field number 6

CyRK.nb.nbrk module

CyRK.nb.nbrk.nbsolve_ivp(diffeq: callable, t_span: Tuple[float, float], y0: ndarray, args: tuple = (), rtol: float = 0.001, atol: float = 1e-06, rtols: ndarray = array([], dtype=float64), atols: ndarray = array([], dtype=float64), max_step: float = inf, first_step: float = None, rk_method: int = 1, t_eval: ndarray = array([], dtype=float64), capture_extra: bool = False, interpolate_extra: bool = False, max_num_steps: int = 0, warnings: bool = True)[source]

A Numba-safe Runge-Kutta Integrator based on Scipy’s solve_ivp RK integrator [1], [2].

Parameters:

  • diffeq (callable) – An njit-compiled function that defines the derivatives of the problem.

  • t_span (Tuple[float, float]) – A tuple of the beginning and end of the integration domain’s dependent variables.

  • y0 (np.ndarray) – 1D array of the initial values of the problem at t_span[0]

  • args (tuple = tuple()) – Any additional arguments that are passed to dffeq.

  • rtol (float = 1.e-3) – Integration relative tolerance used to determine optimal step size.

  • atol (float = 1.e-6) – Integration absolute tolerance used to determine optimal step size.

  • rtols (np.ndarray = EMPTY_ARR) – Array of relative tolerances (size of y0).

  • atols (np.ndarray = EMPTY_ARR) – Array of absolute tolerances (size of y0).

  • max_step (float = np.inf) – Maximum allowed step size.

  • first_step (float = None) – Initial step size. If None, then the function will attempt to determine an appropriate initial step.

  • rk_method (int = 1) –

    The type of RK method used for integration

    0 = RK23 1 = RK45 2 = DOP853

  • t_eval (np.ndarray = None) –

    If provided, then the function will interpolate the integration results to provide them at the

    requested t-steps.

  • capture_extra (bool = False) – If True, then extra output will be captured from the differential equation. See CyRK’s Documentation/Extra Output.md for more information

  • interpolate_extra (bool = False) –

    If True, then extra output will be interpolated (along with y) at t_eval. Otherwise, y will be interpolated

    and then differential equation will be called to find the output at each t in t_eval.

  • max_num_steps (int = 0) – Maximum number of steps integrator is allowed to take. If set to 0 (the default) then an infinite number of steps are allowed.

  • warnings (bool = True) – If True, then warnings will be raised which can slow down integration.

References

Returns:

  • time_domain (np.ndarray) – The final time domain. This is equal to t_eval if it was provided.

  • y_results (np.ndarray) –

    The solution of the differential equation provided for each time_result.
    If capture_extra was set to True then this will output both y and any extra parameters calculated by the

    differential equation. The format of this output will look like:

    y_results[0:y_size, :]          = ... # Actual y-results calculated by the diffeq solver
y_results[y_size:extra_size, :] = ... # Extra outputs captured alongside y during integration

  • success (bool) – Final integration success flag.

  • message (str) – Any integration messages, useful if success=False.

CyRK.nb.numba_c_api module

CyRK.nb.numba_c_api.get_args_ptr_func_ptr()
CyRK.nb.numba_c_api.get_args_size_func_ptr()
CyRK.nb.numba_c_api.get_call_call_func_ptr()
CyRK.nb.numba_c_api.get_call_call_vectorize_func_ptr()
CyRK.nb.numba_c_api.get_capture_dense_func_ptr()
CyRK.nb.numba_c_api.get_capture_extra_func_ptr()
CyRK.nb.numba_c_api.get_direction_func_ptr()
CyRK.nb.numba_c_api.get_dy_now_ptr_func_ptr()
CyRK.nb.numba_c_api.get_free_func_ptr()
CyRK.nb.numba_c_api.get_message_buffer_func_ptr()
CyRK.nb.numba_c_api.get_method_func_ptr()
CyRK.nb.numba_c_api.get_num_dy_func_ptr()
CyRK.nb.numba_c_api.get_num_interpolates_func_ptr()
CyRK.nb.numba_c_api.get_num_y_func_ptr()
CyRK.nb.numba_c_api.get_size_func_ptr()
CyRK.nb.numba_c_api.get_solve_func_ptr()
CyRK.nb.numba_c_api.get_status_func_ptr()
CyRK.nb.numba_c_api.get_status_message_buffer_func_ptr()
CyRK.nb.numba_c_api.get_steps_taken_func_ptr()
CyRK.nb.numba_c_api.get_success_func_ptr()
CyRK.nb.numba_c_api.get_t_func_ptr()
CyRK.nb.numba_c_api.get_t_now_func_ptr()
CyRK.nb.numba_c_api.get_y_func_ptr()
CyRK.nb.numba_c_api.get_y_now_ptr_func_ptr()

CyRK.nb.numba_solver module

class CyRK.nb.numba_solver.NbCySolverResult(*args, **kwargs)[source]

Bases: NbCySolverResult

Numba-compatible wrapper for the C++ CySolverResult class.

Parameters:

ptr (int) – Memory address of the underlying C++ CySolverResult instance.

class_type = jitclass.NbCySolverResult#7e2e466c5b80<_ptr:int64>
CyRK.nb.numba_solver.get_method_str(method_int: int)[source]

Map integration method integers to strings.

Parameters:

method_int (int) – Integer identifier for the ODE method.

Returns:

String name of the integration method.

Return type:

str

CyRK.nb.numba_solver.get_status_message_str(status_code: int)[source]

Numba-safe string extractor for C++ Error Code map.

Parameters:

status_code (int) – The error code to look up.

Returns:

The descriptive error message from the C++ backend.

Return type:

str

CyRK.nb.numba_solver.nb_diffeq_addr(diffeq_func)[source]

Compile a Python function to a C-callback and return its memory address.

Parameters:

diffeq_func (callable) – The differential equation function to compile.

Returns:

Memory address of the compiled C-callback.

Return type:

int

CyRK.nb.numba_solver.nbsolve2_ivp(diffeq_address: int64, t_span: Tuple[float, float], y0: ndarray, method: str = 'RK45', t_eval: ndarray | None = None, dense_output: bool = False, args: ndarray | None = None, rtol: float = 0.001, atol: float = 1e-06, rtols: ndarray | None = None, atols: ndarray | None = None, num_extra: int = 0, expected_size: int = 0, max_step: float = 18446744073709551615, first_step: float = 0.0, max_num_steps: int = 0, max_ram_MB: int = 2000, force_retain_solver: bool = True)[source]

Numba-compiled entry point for the C++ CyRK ODE solver.

Parameters:

  • diffeq_address (int) – Memory address of the compiled differential equation C-callback.

  • t_span (tuple of float) – Interval of integration (t0, tf).

  • y0 (numpy.ndarray) – Initial state vector.

  • method (str, optional) – Integration method (‘RK45’, ‘RK23’, ‘DOP853’). Default is ‘RK45’.

  • t_eval (numpy.ndarray, optional) – Times at which to store the computed solution.

  • dense_output (bool, optional) – Whether to compute a continuous-time polynomial interpolation. Default is False.

  • args (numpy.ndarray, optional) – Additional arguments passed to the differential equation.

  • rtol (float, optional) – Relative and absolute tolerances.

  • atol (float, optional) – Relative and absolute tolerances.

  • rtols (numpy.ndarray, optional) – Vector-valued relative and absolute tolerances.

  • atols (numpy.ndarray, optional) – Vector-valued relative and absolute tolerances.

  • num_extra (int, optional) – Number of extra output variables computed by the diffeq.

  • expected_size (int, optional) – Estimated number of steps to pre-allocate memory.

  • max_step (float, optional) – Maximum allowed step size.

  • first_step (float, optional) – Initial step size guess.

  • max_num_steps (int, optional) – Maximum number of steps allowed before termination.

  • max_ram_MB (int, optional) – Maximum memory allowed for solution storage in Megabytes.

  • force_retain_solver (bool, optional) – Whether to keep the solver instance alive after integration.

Returns:

A jitclass object containing the integration results and solution views.

Return type:

NbCySolverResult

CyRK.nb.numba_solver.njit_test_nbsolve_ivp(diffeq_address: int64, t_span: Tuple[float, float], y0: ndarray, method: str = 'RK45', t_eval: ndarray | None = None, dense_output: bool = False, args: ndarray | None = None, rtol: float = 0.001, atol: float = 1e-06, rtols: ndarray | None = None, atols: ndarray | None = None, num_extra: int = 0, expected_size: int = 0, max_step: float = 18446744073709551615, first_step: float = 0.0, max_num_steps: int = 0, max_ram_MB: int = 2000, force_retain_solver: bool = True)[source]

Numba-compiled test wrapper to verify njit-to-njit call performance.

Parameters:

nbsolve2_ivp] ([Parameters mirror)

Returns:

Frees the result object internally after execution.

Return type:

None

CyRK.nb.numba_solver.test_nbsolve_ivp(diffeq: callable, t_span: Tuple[float, float], y0: ndarray, method: str = 'RK45', t_eval: ndarray = None, dense_output: bool = False, args: ndarray = None, rtol: float = 0.001, atol: float = 1e-06, rtols: ndarray = None, atols: ndarray = None, num_extra: int = 0, expected_size: int = 0, max_step: float = 18446744073709551615, first_step: float = 0.0, max_num_steps: int = 0, max_ram_MB: int = 2000, force_retain_solver: bool = True)[source]

Pure-Python test wrapper for the Numba solver.

Parameters:

callable] ([Parameters mirror nbsolve2_ivp except diffeq is a)

Returns:

Frees the result object internally after execution.

Return type:

None

CyRK.nb.numba_solver.to_hex(n: int)[source]

Numba-safe integer to hex string converter.

Parameters:

n (int) – Integer to convert.

Returns:

Hexadecimal string representation.

Return type:

str