PyBAMMSolvers

0.8.1 verified Fri May 01 auth: no python

Python interface for the IDAKLU solver for block algebraic multigrid methods. Current version 0.8.1, requires Python >=3.10,<3.15. Development is active with occasional releases.

pip install pybammsolvers

Common errors

error ModuleNotFoundError: No module named 'idaklu' ↓

cause Importing the solver directly without the package prefix.

fix

Use 'from pybammsolvers import idaklu' instead of 'import idaklu'.

error TypeError: idaklu() missing 2 required positional arguments: 'A' and 'b' ↓

cause Calling idaklu with only one argument or with keyword arguments incorrectly.

fix

Call idaklu(A, b) with the matrix first, right-hand side second.

Warnings

gotcha The idaklu function expects the matrix A in CSR or CSC format. Dense arrays will fail or produce incorrect results. ↓

fix Convert to scipy.sparse.csr_matrix before passing to idaklu.

gotcha The solver may not converge for indefinite matrices; it is designed for SPD-like systems. ↓

fix Ensure the matrix is symmetric positive definite or at least positive real.

deprecated The function signature changed between 0.7.x and 0.8.x: previously the order of arguments was (A, b, ...) but now also supports additional options as keyword arguments. ↓

fix Review call signature: idaklu(A, b, reorder=1) works for basic usage.

Imports

idaklu
wrong
```
import idaklu
```
correct
```
from pybammsolvers import idaklu
```
The solver is inside the pybammsolvers namespace.

Quickstart

Solves a sparse linear system A x = b using the IDAKLU solver.

import numpy as np
from scipy.sparse import csr_matrix
from pybammsolvers import idaklu

# Create a simple sparse matrix (CSR format)
n = 100
A = csr_matrix(np.random.rand(n, n) + 10 * np.eye(n))
b = np.random.rand(n)

# Solve using IDAKLU
x = idaklu(A, b)
print(x[:5])