copt.minimize_APGD¶

copt.
minimize_APGD
(f_grad, x0, g_prox=None, tol=1e06, max_iter=500, verbose=0, callback=None, line_search=True, step_size=None, max_iter_backtracking=100, backtracking_factor=0.6)[source]¶ Accelerated proximal gradient descent.
Solves problems of the form
minimize_x f(x) + alpha g(x)where we have access to the gradient of f and to the proximal operator of g.
Parameters:  f_grad – loss function, differentiable
 g_prox – penalty, proximable
 g_prox – g_prox(x, alpha) returns the proximal operator of g at x with parameter alpha.
 x0 – arraylike Initial guess
 line_search – boolean Whether to perform backtracking (i.e. linesearch) or not.
 max_iter – int Maximum number of iterations.
 verbose – int Verbosity level, from 0 (no output) to 2 (output on each iteration)
 step_size – float Starting value for the linesearch procedure. XXX
 callback – callable callback function (optional).
Returns:  The optimization result represented as a
scipy.optimize.OptimizeResult
object. Important attributes are:x
the solution array,success
a Boolean flag indicating if the optimizer exited successfully andmessage
which describes the cause of the termination. See scipy.optimize.OptimizeResult for a description of other attributes.
Return type: res
References
Amir Beck and Marc Teboulle. “Gradientbased algorithms with applications to signal recovery.” Convex optimization in signal processing and communications (2009)