diff options
Diffstat (limited to 'jpa_test/convex_optimization.py')
| -rw-r--r-- | jpa_test/convex_optimization.py | 74 |
1 files changed, 66 insertions, 8 deletions
diff --git a/jpa_test/convex_optimization.py b/jpa_test/convex_optimization.py index a9556ae..530e3f5 100644 --- a/jpa_test/convex_optimization.py +++ b/jpa_test/convex_optimization.py @@ -32,7 +32,8 @@ def l1obj_l2constraint(M_val, w_val): y_diff = tensor.grad(y, theta_) y_hess = z[0] * theano.gradient.hessian(y, theta_) f_x = theano.function([theta], [y, y_diff], allow_input_downcast=True) - f_xz = theano.function([theta, z], [y, y_diff, y_hess], allow_input_downcast=True) + f_xz = theano.function([theta, z], [y, y_diff, y_hess], + allow_input_downcast=True) def F(x=None, z=None): if x is None: @@ -60,18 +61,75 @@ def l1obj_l2constraint(M_val, w_val): return 1 - np.exp(theta), theta +@timeout.timeout(10) +def l1obj_l2penalization(M_val, w_val, lbda): + """ + Solves: + min - sum_j theta_j + lbda*|e^{M*theta} - (1 - w)|_2 + s.t theta_j <= 0 + """ + assert len(M_val) == len(w_val) + + if M_val.dtype == bool: + M_val = M_val.astype('float32') + + if type(lbda) == int: + lbda = np.array(lbda) + + m, n = M_val.shape + + theta = tensor.row().T + z = tensor.row().T + theta_ = theta.flatten() + z_ = z.flatten() + M = theano.shared(M_val.astype(theano.config.floatX)) + w = theano.shared(w_val.astype(theano.config.floatX)) + lbda = theano.shared(lbda.astype(theano.config.floatX)) + y = (theta_).norm(1) + lbda * ( + tensor.exp(M.dot(theta_)) - (1 - w)).norm(2) + y_diff = tensor.grad(y, theta_) + y_hess = z[0] * theano.gradient.hessian(y, theta_) + f_x = theano.function([theta], [y, y_diff], allow_input_downcast=True) + f_xz = theano.function([theta, z], [y, y_diff, y_hess], + allow_input_downcast=True) + + def F(x=None, z=None): + if x is None: + return 0, cvxopt.matrix(.0001, (n,1)) + elif z is None: + y, y_diff = f_x(x) + return cvxopt.matrix(float(y), (1, 1)),\ + cvxopt.matrix(y_diff.astype("float64")).T + else: + y, y_diff, y_hess = f_xz(x, z) + return cvxopt.matrix(float(y), (1, 1)), \ + cvxopt.matrix(y_diff.astype("float64")).T, \ + cvxopt.matrix(y_hess.astype("float64")) + + G = cvxopt.spdiag([1 for i in xrange(n)]) + h = cvxopt.matrix(0.0, (n,1)) + + cvxopt.solvers.options['show_progress'] = False + try: + theta = cvxopt.solvers.cp(F, G, h)['x'] + except ArithmeticError: + print "ArithmeticError thrown, change initial point"+\ + " given to the solver" + + return 1 - np.exp(theta), theta + + def test(): """ unit test """ - G = cascade_creation.InfluenceGraph(max_proba=.5) - G.erdos_init(n=100, p = .8) - A = cascade_creation.generate_cascades(G, .1, 20) + lbda = 10 + G = cascade_creation.InfluenceGraph(max_proba=.8) + G.erdos_init(n=100, p = .1) + A = cascade_creation.generate_cascades(G, .1, 2000) M_val, w_val = cascade_creation.icc_matrixvector_for_node(A, 0) - assert len(M_val) == len(w_val) - print np.linalg.matrix_rank(M_val) - p_vec, theta = l1obj_l2constraint(M_val, w_val) - print len(p_vec) + p_vec, theta = l1obj_l2penalization(M_val, w_val, lbda) + print p_vec if __name__=="__main__": test() |
