utils.py: Utilities

simba.utils.halve_matrix(mat: sympy.matrices.dense.MutableDenseMatrix)

Halve the dimensions of the given matrix, truncating where necessary.

Throws DimensionError if matrix dimensions are not even.

Example:

>>>from sympy import Matrix >>>m = Matrix([[1, 2], [3, 4]]) >>>assert halve_matrix(m) == Matrix([[1]])

simba.utils.solve_matrix_eqn(eqn, x)

Solve matrix eqn for x, where eqn is a matrix equation or list of matrix equations (assumed equal to zero on RHS) and x is a sympy MatrixSymbol object.

Transforms all solutions to list of matrices (same shape as x).

simba.utils.construct_permutation_matrix(n: int) → sympy.matrices.dense.MutableDenseMatrix

Construct permutation matrix that reorders the elements so that (1, 2, 3, 11, 22, 33) -> (1, 11, 2, 22, 3, 33)

simba.utils.simplify(expr, rhs=None)

Simplify given expression or equation, using wolframscript if config.params[‘wolframscript’] is True

simba.utils.adiabatically_eliminate(expr: sympy.core.expr.Expr, gamma: sympy.core.symbol.Symbol) → sympy.core.expr.Expr

Eliminate terms from expr which are very small compared to gamma which is much larger than any other frequency.