lib module

Utility functions to compute the \(\ell_2\) norm of a linear operator.

lib.op_norm(A, At, im_size, tol, max_iter, verbose)

Computes the maximum eigen value of the compound operator \(A^TA\).

Parameters

• A (anonymous function) – Direct linear operator \(A\).

• At (anonymous function) – Adjoint of the linear operator \(A\), denoted \(A^T\).

• im_size (array (int)) – Size of the variable on which \(A\) operates.

• tol (double) – Convergence tolerance (relative variation between two consecutive iterates).

• max_iter (int) – Maximum number of iterations.

• verbose (int) – Activate verbose mode (if > 0).

Returns

val – Maximum eigenvalue of the linear operator \(A^TA\).

Return type

double