diff options
Diffstat (limited to 'Wrappers')
| -rwxr-xr-x | Wrappers/Python/ccpi/optimisation/algorithms/CGLS.py | 138 | ||||
| -rw-r--r-- | Wrappers/Python/demos/CGLS_examples/CGLS_Tikhonov.py | 71 |
2 files changed, 136 insertions, 73 deletions
diff --git a/Wrappers/Python/ccpi/optimisation/algorithms/CGLS.py b/Wrappers/Python/ccpi/optimisation/algorithms/CGLS.py index 15acc31..28b19f6 100755 --- a/Wrappers/Python/ccpi/optimisation/algorithms/CGLS.py +++ b/Wrappers/Python/ccpi/optimisation/algorithms/CGLS.py @@ -46,78 +46,94 @@ class CGLS(Algorithm): self.set_up(x_init =kwargs['x_init'], operator=kwargs['operator'], data =kwargs['data']) - + def set_up(self, x_init, operator , data ): - self.r = data.copy() - self.x = x_init * 0 - - self.operator = operator - self.d = operator.adjoint(self.r) - - - self.normr2 = self.d.squared_norm() + self.x = x_init + self.r = data - self.operator.direct(self.x) + self.s = self.operator.adjoint(self.r) - self.s = self.operator.domain_geometry().allocate() - #if isinstance(self.normr2, Iterable): - # self.normr2 = sum(self.normr2) - #self.normr2 = numpy.sqrt(self.normr2) - #print ("set_up" , self.normr2) - n = Norm2Sq(operator, self.data) - self.loss.append(n(x_init)) - self.configured = True + self.p = self.s + self.norms0 = self.s.norm() + self.gamma = self.norms0**2 + self.normx = self.x.norm() + self.xmax = self.normx + self.configured = True + +# def set_up(self, x_init, operator , data ): +# +# self.r = data.copy() +# self.x = x_init * 0 +# +# self.operator = operator +# self.d = operator.adjoint(self.r) +# +# +# self.normr2 = self.d.squared_norm() +# +# self.s = self.operator.domain_geometry().allocate() +# #if isinstance(self.normr2, Iterable): +# # self.normr2 = sum(self.normr2) +# #self.normr2 = numpy.sqrt(self.normr2) +# #print ("set_up" , self.normr2) +# n = Norm2Sq(operator, self.data) +# self.loss.append(n(x_init)) +# self.configured = True def update(self): self.update_new() - def update_old(self): - Ad = self.operator.direct(self.d) - #norm = (Ad*Ad).sum() - #if isinstance(norm, Iterable): - # norm = sum(norm) - norm = Ad.squared_norm() - alpha = self.normr2/norm - self.x += (self.d * alpha) - self.r -= (Ad * alpha) - s = self.operator.adjoint(self.r) - - normr2_new = s.squared_norm() - #if isinstance(normr2_new, Iterable): - # normr2_new = sum(normr2_new) - #normr2_new = numpy.sqrt(normr2_new) - #print (normr2_new) - - beta = normr2_new/self.normr2 - self.normr2 = normr2_new - self.d = s + beta*self.d - def update_new(self): - - Ad = self.operator.direct(self.d) - norm = Ad.squared_norm() - if norm == 0.: - print ('norm = 0, cannot update solution') - print ("self.d norm", self.d.squared_norm(), self.d.as_array()) - raise StopIteration() - alpha = self.normr2/norm - if alpha == 0.: - print ('alpha = 0, cannot update solution') - raise StopIteration() - self.d *= alpha - Ad *= alpha - self.r -= Ad - self.x += self.d + self.q = self.operator.direct(self.p) + delta = self.q.squared_norm() + alpha = self.gamma/delta + + self.x += alpha * self.p + self.r -= alpha * self.q + + self.s = self.operator.adjoint(self.r) + + self.norms = self.s.norm() + self.gamma1 = self.gamma + self.gamma = self.norms**2 + self.beta = self.gamma/self.gamma1 + self.p = self.s + self.beta * self.p + + self.normx = self.x.norm() + self.xmax = numpy.maximum(self.xmax, self.normx) - self.operator.adjoint(self.r, out=self.s) - s = self.s - - normr2_new = s.squared_norm() - beta = normr2_new/self.normr2 - self.normr2 = normr2_new - self.d *= (beta/alpha) - self.d += s + if self.gamma<=1e-6: + raise StopIteration() +# def update_new(self): +# +# Ad = self.operator.direct(self.d) +# norm = Ad.squared_norm() +# +# if norm <= 1e-3: +# print ('norm = 0, cannot update solution') +# #print ("self.d norm", self.d.squared_norm(), self.d.as_array()) +# raise StopIteration() +# alpha = self.normr2/norm +# if alpha <= 1e-3: +# print ('alpha = 0, cannot update solution') +# raise StopIteration() +# self.d *= alpha +# Ad *= alpha +# self.r -= Ad +# +# self.x += self.d +# +# self.operator.adjoint(self.r, out=self.s) +# s = self.s +# +# normr2_new = s.squared_norm() +# +# beta = normr2_new/self.normr2 +# self.normr2 = normr2_new +# self.d *= (beta/alpha) +# self.d += s def update_objective(self): a = self.r.squared_norm() diff --git a/Wrappers/Python/demos/CGLS_examples/CGLS_Tikhonov.py b/Wrappers/Python/demos/CGLS_examples/CGLS_Tikhonov.py index 653e191..63a2254 100644 --- a/Wrappers/Python/demos/CGLS_examples/CGLS_Tikhonov.py +++ b/Wrappers/Python/demos/CGLS_examples/CGLS_Tikhonov.py @@ -47,8 +47,8 @@ from ccpi.astra.ops import AstraProjectorSimple # Load Data loader = TestData(data_dir=os.path.join(sys.prefix, 'share','ccpi')) -N = 150 -M = 150 +N = 64 +M = 64 data = loader.load(TestData.SIMPLE_PHANTOM_2D, size=(N,M), scale=(0,1)) ig = data.geometry @@ -82,20 +82,19 @@ plt.colorbar() plt.show() # Setup and run the CGLS algorithm -#alpha = 50 -#Grad = Gradient(ig) +alpha = 5 +Grad = Gradient(ig) # ## Form Tikhonov as a Block CGLS structure -#op_CGLS = BlockOperator( Aop, alpha * Grad, shape=(2,1)) -#block_data = BlockDataContainer(noisy_data, Grad.range_geometry().allocate()) +op_CGLS = BlockOperator( Aop, alpha * Grad, shape=(2,1)) +block_data = BlockDataContainer(noisy_data, Grad.range_geometry().allocate()) # -#x_init = ig.allocate() -#cgls = CGLS(x_init=x_init, operator=op_CGLS, data=block_data) -#cgls.max_iteration = 1000 -#cgls.update_objective_interval = 200 -#cgls.run(1000,verbose=False) +x_init = ig.allocate() +cgls = CGLS(x_init=x_init, operator=op_CGLS, data=block_data) +cgls.max_iteration = 1000 +cgls.update_objective_interval = 200 +cgls.run(1000,verbose=True) -#%% # Show results plt.figure(figsize=(5,5)) plt.imshow(cgls.get_output().as_array()) @@ -103,4 +102,52 @@ plt.title('CGLS reconstruction') plt.colorbar() plt.show() +#%% +from ccpi.optimisation.operators import SparseFiniteDiff +import astra +import numpy + +try: + from cvxpy import * + cvx_not_installable = True +except ImportError: + cvx_not_installable = False + + +if cvx_not_installable: + + + ##Construct problem + u = Variable(N*M) + #q = Variable() + + DY = SparseFiniteDiff(ig, direction=0, bnd_cond='Neumann') + DX = SparseFiniteDiff(ig, direction=1, bnd_cond='Neumann') + + regulariser = alpha * sum_squares(norm(vstack([DX.matrix() * vec(u), DY.matrix() * vec(u)]), 2, axis = 0)) + + # create matrix representation for Astra operator + + vol_geom = astra.create_vol_geom(N, N) + proj_geom = astra.create_proj_geom('parallel', 1.0, detectors, angles) + + proj_id = astra.create_projector('strip', proj_geom, vol_geom) + + matrix_id = astra.projector.matrix(proj_id) + + ProjMat = astra.matrix.get(matrix_id) + + fidelity = sum_squares( ProjMat * u - noisy_data.as_array().ravel()) + + solver = SCS + obj = Minimize( regulariser + fidelity) + prob = Problem(obj, constraints) + result = prob.solve(verbose = True, solver = solver) + + + + + + + |