Exemple #1
0
solution = solver.problem.coefs

l1_soln = np.fabs(D * solution).sum()

tfocs_penalty = maxnorm(499, l=l1_soln)
tfocs_loss = quadratic.affine(DT, -Y, l=0.5)
tfocs_loss.coefs = np.zeros(499)
tfocs_problem = tfocs_loss.add_seminorm(tfocs_penalty)
tfocs_solver = FISTA(tfocs_problem)
tfocs_solver.debug = True
tfocs_solver.fit(max_its=1000, tol=1e-10)
tfocs_dual_solution = tfocs_problem.coefs
tfocs_primal_solution = Y - DT * tfocs_dual_solution

import pylab
pylab.scatter(np.arange(Y.shape[0]), Y, c='r')
pylab.plot(solution, color='yellow', linewidth=5)
pylab.plot(tfocs_primal_solution, color='black', linewidth=3)


newl1 = l1norm(D, l=l1_soln)
conjugate = quadratic.shift(Y, l=0.5)
from regreg.constraint import constraint
loss_constraint = constraint(conjugate, newl1)
new_solver = FISTA(loss_constraint.dual_problem())
new_solver.debug = True
new_solver.fit(max_its=1000, tol=1e-10)
soln3 = loss_constraint.primal_from_dual(new_solver.problem.coefs)
pylab.plot(soln3, color='gray', linewidth=1)

Exemple #2
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fused = l1norm(D, l=20)

penalty = seminorm(sparsity,fused)


Y = np.random.standard_normal(500); Y[100:150] += 7; Y[250:300] += 14
loss = l2normsq.shift(-Y, l=0.5)
problem = loss.add_seminorm(penalty)
solver = FISTA(problem)
solver.fit(max_its=100, tol=1e-10)
solution = solver.problem.coefs

import pylab
pylab.scatter(np.arange(Y.shape[0]), Y, c='r')
pylab.plot(solution, color='yellow', linewidth=5)

l1_fused = np.fabs(D * solution).sum()
l1_sparsity = np.fabs(solution).sum()

new_fused = l1norm(D, l=l1_fused)
new_sparsity = l1norm(500, l=l1_sparsity)
conjugate = l2normsq.shift(Y, l=0.5)
from regreg.constraint import constraint
loss_constraint = constraint(conjugate, new_fused, new_sparsity)
constrained_solver = FISTA(loss_constraint.dual_problem())
constrained_solver.debug = True
constrained_solver.fit(max_its=2000, tol=1e-10)
constrained_solution = loss_constraint.primal_from_dual(constrained_solver.problem.coefs)
pylab.plot(constrained_solution, color='black', linewidth=3)

Exemple #3
0
solver = FISTA(problem)
solver.fit(max_its=100, tol=1e-10)
solution = solver.problem.coefs

l1_soln = np.fabs(D * solution).sum()

tfocs_penalty = maxnorm(499, l=l1_soln)
tfocs_loss = l2normsq.affine(DT, -Y, l=0.5)
tfocs_loss.coefs = np.zeros(499)
tfocs_problem = tfocs_loss.add_seminorm(tfocs_penalty)
tfocs_solver = FISTA(tfocs_problem)
tfocs_solver.debug = True
tfocs_solver.fit(max_its=1000, tol=1e-10)
tfocs_dual_solution = tfocs_problem.coefs
tfocs_primal_solution = Y - DT * tfocs_dual_solution

import pylab
pylab.scatter(np.arange(Y.shape[0]), Y, c='r')
pylab.plot(solution, color='yellow', linewidth=5)
pylab.plot(tfocs_primal_solution, color='black', linewidth=3)

newl1 = l1norm(D, l=l1_soln)
conjugate = l2normsq.shift(Y, l=0.5)
from regreg.constraint import constraint
loss_constraint = constraint(conjugate, newl1)
new_solver = FISTA(loss_constraint.dual_problem())
new_solver.debug = True
new_solver.fit(max_its=1000, tol=1e-10)
soln3 = loss_constraint.primal_from_dual(new_solver.problem.coefs)
pylab.plot(soln3, color='gray', linewidth=1)