Numba Integrators

Numba Integrators is collection numerical integrators based on the ones in SciPy. Aim is to make them faster and much more compatible with Numba.

Table of Contents

• Quick start guide
  • The first steps
    • Installing
    • Importing
    • Example
    • Example of the advanced function

Quick start guide

Here's how you can start

The first steps

Installing

Install Numba Integrators with pip

pip install numba_integrators

Importing

Import name is the same as install name, numba_integrators.

import numba_integrators

Since the package is accessed often, abbreviation ni is used. The abbreviation is used throughout this document.

import numba_integrators as ni

Example

import numba as nb
import numba_integrators as ni
import numpy as np

@nb.njit(nb.float64[:](nb.float64, nb.float64[:]))
def f(t, y):
    '''Differential equation for sine wave'''
    return np.array((y[1], -y[0]))

y0 = np.array((0., 1.))

solver = ni.RK45(f, 0.0, y0,
                 t_bound = 1, atol = 1e-8, rtol = 1e-8)

t = []
y = []

while ni.step(solver):
    t.append(solver.t)
    y.append(solver.y)

print(t)
print(y)

Example of the advanced function

import numba as nb
import numba_integrators as ni
import numpy as np

@nb.njit
def f(t, y, parameters):
    '''Differential equation for sine wave'''
    auxiliary = parameters[0] * y[1]
    dy = np.array((auxiliary, -y[0])) + parameters[1]
    return dy, auxiliary

t0 = 0.
y0 = np.array((0., 1.))
parameters = (2., np.array((-1., 1.)))

# Numba type signatures
parameters_signature = nb.types.Tuple((nb.float64, nb.float64[:]))
auxiliary_signature = nb.float64
solver_type = ni.RK45

Solver = ni.Advanced(parameters_signature, auxiliary_signature, solver_type)
solver = Solver(f, t0, y0, parameters,
                t_bound = 1, atol = 1e-8, rtol = 1e-8)

t = []
y = []
auxiliary = []

while ni.step(solver):
    t.append(solver.t)
    y.append(solver.y)
    auxiliary.append(solver.auxiliary)

print(t)
print(y)
print(auxiliary)

Changelog

0.3.1 2024-07-18

• Fast forward
• Refactoring

0.2.2 2023-11-07

• Dev tools update

0.2.1 2023-08-11

• Advanced mode solver to handle functions with parameters and auxiliary output

0.1.2 2023-08-06

• Fixes

0.1.1 2023-08-05

• Initial working version

0.0.3 2023-05-14

• Inital working state