def test_interpolation_time(self):
d = 3
l = 5
n_x = 1
N = 1000
from numpy import column_stack, minimum, maximum
smin = [-1]*d
smax = [1]*d
from dolo.numeric.interpolation.smolyak import SmolyakGrid
sg = SmolyakGrid(smin,smax,l)
print(sg.grid.shape)
from numpy import exp
values = column_stack( [sg.grid[:,0] + exp(sg.grid[:,0])]*n_x )
print(values.shape)
sg.set_values(values)
from numpy import random
points = random.rand( d*N )
points = minimum(points,1)
points = maximum(points,-1)
points = points.reshape( (N,d) )
# I need to add the corners of the grid !
import time
t = time.time()
for i in range(10):
test1 = sg(points)
s = time.time()
print('Smolyak : {}'.format(s-t))
def test_interpolation_time(self):
d = 3
l = 5
n_x = 1
N = 1000
from numpy import column_stack, minimum, maximum
smin = [-1] * d
smax = [1] * d
from dolo.numeric.interpolation.smolyak import SmolyakGrid
sg = SmolyakGrid(smin, smax, l)
print(sg.grid.shape)
from numpy import exp
values = column_stack([sg.grid[:, 0] + exp(sg.grid[:, 0])] * n_x)
print(values.shape)
sg.set_values(values)
from numpy import random
points = random.rand(d * N)
points = minimum(points, 1)
points = maximum(points, -1)
points = points.reshape((N, d))
# I need to add the corners of the grid !
import time
t = time.time()
for i in range(10):
test1 = sg(points)
s = time.time()
print('Smolyak : {}'.format(s - t))
def test_smolyak(self):
import numpy
f = lambda x: numpy.column_stack([
x[:,0] * x[:,1]**0.5,
x[:,1] * x[:,1] - x[:,0] * x[:,0]
])
smin = [0.5,0.1],
smax = [2,3]
bounds = numpy.row_stack([smin,smax])
from dolo.numeric.interpolation.smolyak import SmolyakGrid
sg = SmolyakGrid(smin,smax,3)
values = f(sg.grid)
sg.set_values(values)
theta_0 = sg.theta.copy()
def fobj(theta):
sg.theta = theta
return sg(sg.grid)
fobj(theta_0)
def test_smolyak_plot_3d(selfs):
import numpy
from dolo.numeric.interpolation.smolyak import SmolyakGrid
bounds = numpy.column_stack([[-1, 1]] * 3)
sg = SmolyakGrid(bounds[0, :], bounds[1, :], 3)
sg.plot_grid()
def test_smolyak_plot_3d(selfs):
import numpy
from dolo.numeric.interpolation.smolyak import SmolyakGrid
bounds = numpy.column_stack([[-1, 1]] * 3)
sg = SmolyakGrid(bounds[0, :], bounds[1, :], 3)
sg.plot_grid()
def test_interpolation_time(self):
d = 3
l = 5
n_x = 1
N = 1000
from numpy import row_stack, minimum, maximum
smin = [-1]*d
smax = [1]*d
from dolo.numeric.interpolation.smolyak import SmolyakGrid
sg = SmolyakGrid(smin,smax,l)
from numpy import exp
values = row_stack( [sg.grid[0,:] + exp(sg.grid[1,:])]*n_x )
sg.set_values(values)
from numpy import random
points = random.rand( d*N )
points = minimum(points,1)
points = maximum(points,-1)
points = points.reshape( (d,N) )
# I need to add the corners of the grid !
import time
t = time.time()
for i in range(10):
test1 = sg(points)
s = time.time()
print('Smolyak : {}'.format(s-t))
from dolo.numeric.interpolation.interpolation import SparseLinear
sp = SparseLinear(smin,smax,l)
xvalues = sg(sp.grid)
sp.set_values(xvalues)
t = time.time()
for i in range(10):
test2 = sp(points)
s = time.time()
print('Sparse linear : {}'.format(s-t))
import numpy
if False in numpy.isfinite(test2):
print('Problem')
def test_interpolation_time(self):
d = 3
l = 5
n_x = 1
N = 1000
from numpy import row_stack, minimum, maximum
smin = [-1] * d
smax = [1] * d
from dolo.numeric.interpolation.smolyak import SmolyakGrid
sg = SmolyakGrid(smin, smax, l)
from numpy import exp
values = row_stack([sg.grid[0, :] + exp(sg.grid[1, :])] * n_x)
sg.set_values(values)
from numpy import random
points = random.rand(d * N)
points = minimum(points, 1)
points = maximum(points, -1)
points = points.reshape((d, N))
# I need to add the corners of the grid !
import time
t = time.time()
for i in range(10):
test1 = sg(points)
s = time.time()
print('Smolyak : {}'.format(s - t))
from dolo.numeric.interpolation.interpolation import SparseLinear
sp = SparseLinear(smin, smax, l)
xvalues = sg(sp.grid)
sp.set_values(xvalues)
t = time.time()
for i in range(10):
test2 = sp(points)
s = time.time()
print('Sparse linear : {}'.format(s - t))
import numpy
if False in numpy.isfinite(test2):
print('Problem')
def __init__(self, smin, smax, l):
from dolo.numeric.interpolation.smolyak import SmolyakGrid
sg = SmolyakGrid(smin, smax, l)
self.smin = array(smin)
self.smax = array(smax)
self.bounds = row_stack([smin, smax])
vertices = cartesian(zip(smin, smax)).T
self.grid = column_stack([sg.grid, vertices])
def test_smolyak(self):
import numpy
f = lambda x: numpy.column_stack(
[x[:, 0] * x[:, 1]**0.5, x[:, 1] * x[:, 1] - x[:, 0] * x[:, 0]])
a = [0.5, 0.1]
b = [2, 3]
bounds = numpy.row_stack([a, b])
from dolo.numeric.interpolation.smolyak import SmolyakGrid
sg = SmolyakGrid(a, b, 3)
values = f(sg.grid)
sg.set_values(values)
assert (abs(sg(sg.grid) - values).max() < 1e-8)
def test_smolyak_2(self):
import numpy
from dolo.numeric.interpolation.smolyak import SmolyakGrid
d = 5
l = 4
bounds = numpy.row_stack([[-0.5] * d, [0.7] * d])
sg = SmolyakGrid(bounds[0, :], bounds[1, :], l)
f = lambda x: numpy.row_stack(
[x[:, 0] * x[:, 1], x[:, 1] * x[:, 1] - x[:, 0] * x[:, 0]])
values = f(sg.grid)
import time
t = time.time()
for i in range(5):
sg.set_values(sg.grid)
val = sg(sg.grid)
s = time.time()
print(s - t)
def test_smolyak_2(self):
import numpy
from dolo.numeric.interpolation.smolyak import SmolyakGrid
d = 5
l = 4
bounds = numpy.row_stack([[-0.5] * d, [0.7] * d])
sg = SmolyakGrid(bounds[0, :], bounds[1, :], l)
f = lambda x: numpy.row_stack([x[0, :] * x[1, :], x[1, :] * x[1, :] - x[0, :] * x[0, :]])
values = f(sg.grid)
import time
t = time.time()
for i in range(5):
sg.set_values(sg.grid)
val = sg(sg.grid)
s = time.time()
print(s - t)
def test_smolyak(self):
import numpy
f = lambda x: numpy.column_stack([
x[:,0] * x[:,1]**0.5,
x[:,1] * x[:,1] - x[:,0] * x[:,0]
])
a = [0.5,0.1]
b = [2,3]
bounds = numpy.row_stack([a,b])
from dolo.numeric.interpolation.smolyak import SmolyakGrid
sg = SmolyakGrid(a,b,3)
values = f(sg.grid)
sg.set_values(values)
assert( abs( sg(sg.grid) - values ).max()<1e-8 )
def test_smolyak(self):
import numpy
f = lambda x: numpy.row_stack(
[x[0, :] * x[1, :]**0.5, x[1, :] * x[1, :] - x[0, :] * x[0, :]])
smin = [0.5, 0.1],
smax = [2, 3]
bounds = numpy.row_stack([smin, smax])
from dolo.numeric.interpolation.smolyak import SmolyakGrid
sg = SmolyakGrid(smin, smax, 3)
values = f(sg.grid)
sg.set_values(values)
theta_0 = sg.theta.copy()
def fobj(theta):
sg.theta = theta
return sg(sg.grid)
fobj(theta_0)
def create_interpolator(grid, interp_method=None):
if interp_method is None:
interp_method = grid.interpolation
if grid.__class__.__name__ == 'SmolyakGrid':
if interp_method is not None and interp_method not in ('chebychev',
'polynomial'):
raise Exception(
"Interpolation method '{}' is not implemented for Smolyak grids."
.format(interp_method))
from dolo.numeric.interpolation.smolyak import SmolyakGrid
dr = SmolyakGrid(grid.a, grid.b, grid.mu)
elif grid.__class__.__name__ == 'CartesianGrid':
if interp_method is not None and interp_method not in (
'spline', 'cspline', ' splines', 'csplines'):
raise Exception(
"Interpolation method '{}' is not implemented for Cartesian grids."
.format(interp_method))
from dolo.numeric.interpolation.splines import MultivariateSplines
dr = MultivariateSplines(grid.a, grid.b, grid.orders)
else:
raise Exception("Unknown grid type '{}'.".format(grid))
return dr
dr_pert = approximate_controls(model, order=1, substitute_auxiliary=True) print(dr_pert.X_bar) from dolo.numeric.interpolation.smolyak import SmolyakGrid from dolo.numeric.global_solve import global_solve dr_smol = global_solve(model, smolyak_order=2, maxit=2, polish=True) smin = dr_smol.bounds[0,:] smax = dr_smol.bounds[1,:] dr_x = SmolyakGrid( smin, smax, 3) dr_h = SmolyakGrid( smin, smax, 3) grid = dr_x.grid xh_init = dr_pert(dr_x.grid) n_x = len(model['variables_groups']['controls']) dr_x.set_values( xh_init[:n_x,:] ) dr_h.set_values( xh_init[n_x:,:] ) #phi = MultilinearInterpolator( smin, smax, [10,10]) #psi = MultilinearInterpolator( smin, smax, [10,10])
def global_solve(model,
bounds=None, verbose=False,
initial_dr=None, pert_order=2,
interp_type='smolyak', smolyak_order=3, interp_orders=None,
maxit=500, numdiff=True, polish=True, tol=1e-8,
integration='gauss-hermite', integration_orders=[],
compiler='numpy', memory_hungry=True,
T=200, n_s=2, N_e=40 ):
def vprint(t):
if verbose:
print(t)
[y, x, parms] = model.read_calibration()
sigma = model.read_covariances()
if initial_dr == None:
initial_dr = approximate_controls(model, order=pert_order)
if interp_type == 'perturbations':
return initial_dr
if bounds is not None:
pass
elif 'approximation' in model['original_data']:
vprint('Using bounds specified by model')
# this should be moved to the compiler
ssmin = model['original_data']['approximation']['bounds']['smin']
ssmax = model['original_data']['approximation']['bounds']['smax']
ssmin = [model.eval_string(str(e)) for e in ssmin]
ssmax = [model.eval_string(str(e)) for e in ssmax]
ssmin = [model.eval_string(str(e)) for e in ssmin]
ssmax = [model.eval_string(str(e)) for e in ssmax]
[y, x, p] = model.read_calibration()
d = {v: y[i] for i, v in enumerate(model.variables)}
d.update({v: p[i] for i, v in enumerate(model.parameters)})
smin = [expr.subs(d) for expr in ssmin]
smax = [expr.subs(d) for expr in ssmax]
smin = numpy.array(smin, dtype=numpy.float)
smax = numpy.array(smax, dtype=numpy.float)
bounds = numpy.row_stack([smin, smax])
bounds = numpy.array(bounds, dtype=float)
else:
vprint('Using bounds given by second order solution.')
from dolo.numeric.timeseries import asymptotic_variance
# this will work only if initial_dr is a Taylor expansion
Q = asymptotic_variance(initial_dr.A.real, initial_dr.B.real, initial_dr.sigma, T=T)
devs = numpy.sqrt(numpy.diag(Q))
bounds = numpy.row_stack([
initial_dr.S_bar - devs * n_s,
initial_dr.S_bar + devs * n_s,
])
smin = bounds[0, :]
smax = bounds[1, :]
if interp_orders == None:
interp_orders = [5] * bounds.shape[1]
if interp_type == 'smolyak':
from dolo.numeric.interpolation.smolyak import SmolyakGrid
dr = SmolyakGrid(bounds[0, :], bounds[1, :], smolyak_order)
elif interp_type == 'spline':
from dolo.numeric.interpolation.splines import MultivariateSplines
dr = MultivariateSplines(bounds[0, :], bounds[1, :], interp_orders)
elif interp_type == 'multilinear':
from dolo.numeric.interpolation.multilinear import MultilinearInterpolator
dr = MultilinearInterpolator(bounds[0, :], bounds[1, :], interp_orders)
elif interp_type == 'sparse_linear':
from dolo.numeric.interpolation.interpolation import SparseLinear
dr = SparseLinear(bounds[0, :], bounds[1, :], smolyak_order)
elif interp_type == 'linear':
from dolo.numeric.interpolation.interpolation import LinearTriangulation, TriangulatedDomain, RectangularDomain
rec = RectangularDomain(smin, smax, interp_orders)
domain = TriangulatedDomain(rec.grid)
dr = LinearTriangulation(domain)
from dolo.compiler.compiler_global import CModel
cm = CModel(model, solve_systems=True, compiler=compiler)
cm = cm.as_type('fg')
if integration == 'optimal_quantization':
from dolo.numeric.quantization import quantization_nodes
# number of shocks
[epsilons, weights] = quantization_nodes(N_e, sigma)
elif integration == 'gauss-hermite':
from dolo.numeric.quadrature import gauss_hermite_nodes
if not integration_orders:
integration_orders = [3] * sigma.shape[0]
[epsilons, weights] = gauss_hermite_nodes(integration_orders, sigma)
vprint('Starting time iteration')
from dolo.numeric.global_solution import time_iteration
from dolo.numeric.global_solution import stochastic_residuals_2, stochastic_residuals_3
xinit = initial_dr(dr.grid)
xinit = xinit.real # just in case...
dr = time_iteration(dr.grid, dr, xinit, cm.f, cm.g, parms, epsilons, weights, x_bounds=cm.x_bounds, maxit=maxit,
tol=tol, nmaxit=50, numdiff=numdiff, verbose=verbose)
if polish and interp_type == 'smolyak': # this works with smolyak only
vprint('\nStarting global optimization')
import time
t1 = time.time()
if cm.x_bounds is not None:
lb = cm.x_bounds[0](dr.grid, parms)
ub = cm.x_bounds[1](dr.grid, parms)
else:
lb = None
ub = None
xinit = dr(dr.grid)
dr.set_values(xinit)
shape = xinit.shape
if not memory_hungry:
fobj = lambda t: stochastic_residuals_3(dr.grid, t, dr, cm.f, cm.g, parms, epsilons, weights, shape, deriv=False)
dfobj = lambda t: stochastic_residuals_3(dr.grid, t, dr, cm.f, cm.g, parms, epsilons, weights, shape, deriv=True)[1]
else:
fobj = lambda t: stochastic_residuals_2(dr.grid, t, dr, cm.f, cm.g, parms, epsilons, weights, shape, deriv=False)
dfobj = lambda t: stochastic_residuals_2(dr.grid, t, dr, cm.f, cm.g, parms, epsilons, weights, shape, deriv=True)[1]
from dolo.numeric.solver import solver
x = solver(fobj, xinit, lb=lb, ub=ub, jac=dfobj, verbose=verbose, method='ncpsolve', serial_problem=False)
dr.set_values(x) # just in case
t2 = time.time()
# test solution
res = stochastic_residuals_2(dr.grid, x, dr, cm.f, cm.g, parms, epsilons, weights, shape, deriv=False)
if numpy.isinf(res.flatten()).sum() > 0:
raise ( Exception('Non finite values in residuals.'))
vprint('Finished in {} s'.format(t2 - t1))
return dr
])
#( sqrt( x[0,:]**2 + x[1,:]**2 + x[2,:]**2 + x[3,:]**2 + x[4,:]**2) )**(1-gamma)/1-gamma
# ( sqrt( reduce(sum, [x[i,:]**2 for i in range(d)], zeros(x[0,:].shape) ) ) )**(1-gamma)/1-gamma
#fun = lambda x: x[0,:]
from dolo.numeric.interpolation.interpolation import RectangularDomain
dom = RectangularDomain(smin,smax,[50]*d)
vals = fun(dom.grid)
# exit()
# if False:
from dolo.numeric.interpolation.smolyak import SmolyakGrid
sg = SmolyakGrid(smin, smax, 4)
sg.set_values( fun(sg.grid))
tstart = time.time()
vals_sg = sg(dom.grid)
tend = time.time()
#
print('Elapsed (smolyak) : {}'.format(tend-tstart))
t1 = time.time()
sp = MultivariateSplines(smin,smax,orders)
t2 = time.time()
sp.set_values( fun(sp.grid))
t3 = time.time()
vals_sp = sp.interpolate(dom.grid)
t4 = time.time()
def time_iteration(model, bounds=None, verbose=False, initial_dr=None,
pert_order=1, with_complementarities=True,
interp_type='smolyak', smolyak_order=3, interp_orders=None,
maxit=500, tol=1e-8, inner_maxit=10,
integration='gauss-hermite', integration_orders=None,
T=200, n_s=3, hook=None):
'''
Finds a global solution for ``model`` using backward time-iteration.
This algorithm iterates on the residuals of the arbitrage equations
Parameters
----------
model : NumericModel
"fg" or "fga" model to be solved
bounds : ndarray
boundaries for approximations. First row contains minimum values.
Second row contains maximum values.
verbose : boolean
if True, display iterations
initial_dr : decision rule
initial guess for the decision rule
pert_order : {1}
if no initial guess is supplied, the perturbation solution at order
``pert_order`` is used as initial guess
with_complementarities : boolean (True)
if False, complementarity conditions are ignored
interp_type : {`smolyak`, `spline`}
type of interpolation to use for future controls
smolyak_orders : int
parameter ``l`` for Smolyak interpolation
interp_orders : 1d array-like
list of integers specifying the number of nodes in each dimension if
``interp_type="spline" ``
Returns
-------
decision rule :
approximated solution
'''
def vprint(t):
if verbose:
print(t)
parms = model.calibration['parameters']
sigma = model.covariances
if initial_dr is None:
if pert_order == 1:
initial_dr = approximate_controls(model)
if pert_order > 1:
raise Exception("Perturbation order > 1 not supported (yet).")
if interp_type == 'perturbations':
return initial_dr
if bounds is not None:
pass
elif model.options and 'approximation_space' in model.options:
vprint('Using bounds specified by model')
approx = model.options['approximation_space']
a = approx['a']
b = approx['b']
bounds = np.row_stack([a, b])
bounds = np.array(bounds, dtype=float)
if interp_orders is None:
interp_orders = approx.get('orders', [5] * bounds.shape[1])
else:
vprint('Using asymptotic bounds given by first order solution.')
from dolo.numeric.timeseries import asymptotic_variance
# this will work only if initial_dr is a Taylor expansion
Q = asymptotic_variance(initial_dr.A.real, initial_dr.B.real,
initial_dr.sigma, T=T)
devs = np.sqrt(np.diag(Q))
bounds = np.row_stack([
initial_dr.S_bar - devs * n_s,
initial_dr.S_bar + devs * n_s,
])
if interp_orders is None:
interp_orders = [5] * bounds.shape[1]
if interp_type == 'smolyak':
from dolo.numeric.interpolation.smolyak import SmolyakGrid
dr = SmolyakGrid(bounds[0, :], bounds[1, :], smolyak_order)
elif interp_type == 'spline':
from dolo.numeric.interpolation.splines import MultivariateSplines
dr = MultivariateSplines(bounds[0, :], bounds[1, :], interp_orders)
if integration == 'optimal_quantization':
from dolo.numeric.discretization import quantization_nodes
# number of shocks
[epsilons, weights] = quantization_nodes(N_e, sigma)
elif integration == 'gauss-hermite':
from dolo.numeric.discretization import gauss_hermite_nodes
if not integration_orders:
integration_orders = [3] * sigma.shape[0]
[epsilons, weights] = gauss_hermite_nodes(integration_orders, sigma)
vprint('Starting time iteration')
# TODO: transpose
grid = dr.grid
xinit = initial_dr(grid)
xinit = xinit.real # just in case...
f = model.functions['arbitrage']
g = model.functions['transition']
# define objective function (residuals of arbitrage equations)
def fun(x):
return step_residual(grid, x, dr, f, g, parms, epsilons, weights)
##
t1 = time.time()
err = 1
x0 = xinit
it = 0
verbit = True if verbose == 'full' else False
if with_complementarities:
lbfun = model.functions['controls_lb']
ubfun = model.functions['controls_ub']
lb = lbfun(grid, parms)
ub = ubfun(grid, parms)
else:
lb = None
ub = None
if verbose:
headline = '|{0:^4} | {1:10} | {2:8} | {3:8} | {4:3} |'
headline = headline.format('N', ' Error', 'Gain', 'Time', 'nit')
stars = '-'*len(headline)
print(stars)
print(headline)
print(stars)
# format string for within loop
fmt_str = '|{0:4} | {1:10.3e} | {2:8.3f} | {3:8.3f} | {4:3} |'
err_0 = 1
while err > tol and it < maxit:
# update counters
t_start = time.time()
it += 1
# update interpolation coefficients (NOTE: filters through `fun`)
dr.set_values(x0)
# Derivative of objective function
sdfun = SerialDifferentiableFunction(fun)
# Apply solver with current decision rule for controls
if with_complementarities:
[x, nit] = ncpsolve(sdfun, lb, ub, x0, verbose=verbit,
maxit=inner_maxit)
else:
[x, nit] = serial_newton(sdfun, x0, verbose=verbit)
# update error and print if `verbose`
err = abs(x-x0).max()
err_SA = err/err_0
err_0 = err
t_finish = time.time()
elapsed = t_finish - t_start
if verbose:
print(fmt_str.format(it, err, err_SA, elapsed, nit))
# Update control vector
x0[:] = x # x0 = x0 + (x-x0)
# call user supplied hook, if any
if hook:
hook(dr, it, err)
# warn and bail if we get inf
if False in np.isfinite(x0):
print('iteration {} failed : non finite value')
return [x0, x]
if it == maxit:
import warnings
warnings.warn(UserWarning("Maximum number of iterations reached"))
# compute final fime and do final printout if `verbose`
t2 = time.time()
if verbose:
print(stars)
print('Elapsed: {} seconds.'.format(t2 - t1))
print(stars)
return dr
def interpolation(self, d):
from itertools import product
import numpy
from numpy import array, column_stack
from dolo.numeric.interpolation.multilinear import multilinear_interpolation
smin = array([0.0] * d)
smax = array([1.0] * d)
orders = numpy.array([4, 3, 5, 6, 3], dtype=numpy.int)
orders = orders[:d]
grid = column_stack([
e for e in product(*[
numpy.linspace(smin[i], smax[i], orders[i]) for i in range(d)
])
])
finer_grid = column_stack(
[e for e in product(*[numpy.linspace(0, 1, 10)] * d)])
if d == 1:
f = lambda g: numpy.row_stack([2 * g[0, :]])
elif d == 2:
f = lambda g: numpy.row_stack([
g[0, :] * g[1, :],
])
elif d == 3:
f = lambda g: numpy.row_stack([
(g[0, :] - g[1, :]) * g[2, :],
])
elif d == 4:
f = lambda g: numpy.row_stack([(g[3, :] - g[1, :]) *
(g[2, :] - g[0, :])])
#
values = f(grid)
finer_grid = numpy.ascontiguousarray(finer_grid)
interpolated_values = multilinear_interpolation(
smin, smax, orders, values, finer_grid)
from dolo.numeric.interpolation.smolyak import SmolyakGrid
sg = SmolyakGrid(smin, smax, 3)
sg.set_values(f(sg.grid))
smol_values = sg(finer_grid)
true_values = f(finer_grid)
err_0 = abs(true_values - smol_values).max()
err_1 = abs(true_values - interpolated_values).max()
# both errors should be 0, because interpolated function is a 2d order polynomial
assert_almost_equal(err_1, 0)
from dolo.numeric.interpolation.multilinear import MultilinearInterpolator
mul_interp = MultilinearInterpolator(smin, smax, orders)
mul_interp.set_values(f(mul_interp.grid))
interpolated_values_2 = mul_interp(finer_grid)
err_3 = (abs(interpolated_values - interpolated_values_2))
assert_almost_equal(err_3, 0)
def interpolation(self, d):
from itertools import product
import numpy
from numpy import array, column_stack
from dolo.numeric.interpolation.multilinear import multilinear_interpolation
smin = array([0.0]*d)
smax = array([1.0]*d)
orders = numpy.array( [4,3,5,6,3], dtype=numpy.int )
orders = orders[:d]
grid = column_stack( [e for e in product(*[numpy.linspace(smin[i],smax[i],orders[i]) for i in range(d)])])
finer_grid = column_stack( [e for e in product(*[numpy.linspace(0,1,10)]*d) ] )
if d == 1:
f = lambda g: numpy.row_stack([
2*g[0,:]
])
elif d == 2:
f = lambda g: numpy.row_stack([
g[0,:] * g[1,:],
])
elif d == 3:
f = lambda g: numpy.row_stack([
(g[0,:] - g[1,:]) * g[2,:],
])
elif d== 4:
f = lambda g: numpy.row_stack([
(g[3,:] - g[1,:]) * (g[2,:] - g[0,:])
])
#
values = f( grid )
finer_grid = numpy.ascontiguousarray(finer_grid)
interpolated_values = multilinear_interpolation(smin, smax, orders, values, finer_grid)
from dolo.numeric.interpolation.smolyak import SmolyakGrid
sg = SmolyakGrid( smin, smax ,3)
sg.set_values( f(sg.grid) )
smol_values = sg(finer_grid)
true_values = f(finer_grid)
err_0 = abs(true_values - smol_values).max()
err_1 = abs(true_values - interpolated_values).max()
# both errors should be 0, because interpolated function is a 2d order polynomial
assert_almost_equal(err_1,0)
from dolo.numeric.interpolation.multilinear import MultilinearInterpolator
mul_interp = MultilinearInterpolator(smin,smax,orders)
mul_interp.set_values( f( mul_interp.grid) )
interpolated_values_2 = mul_interp( finer_grid )
err_3 = (abs(interpolated_values- interpolated_values_2))
assert_almost_equal(err_3,0)
model = yaml_import('../../../examples/global_models/rbc_fgah.yaml')
dr_pert = approximate_controls(model, order=1, substitute_auxiliary=True)
print(dr_pert.X_bar)
from dolo.numeric.interpolation.smolyak import SmolyakGrid
from dolo.numeric.global_solve import global_solve
dr_smol = global_solve(model, smolyak_order=2, maxit=2, polish=True)
smin = dr_smol.bounds[0, :]
smax = dr_smol.bounds[1, :]
dr_x = SmolyakGrid(smin, smax, 3)
dr_h = SmolyakGrid(smin, smax, 3)
grid = dr_x.grid
xh_init = dr_pert(dr_x.grid)
n_x = len(model['variables_groups']['controls'])
dr_x.set_values(xh_init[:n_x, :])
dr_h.set_values(xh_init[n_x:, :])
#phi = MultilinearInterpolator( smin, smax, [10,10])
#psi = MultilinearInterpolator( smin, smax, [10,10])
import numpy
def generatebenchmarkdata(m, n):
seedarr = [54321, 456789, 9876512, 7919820, 10397531]
folder = "results"
samplearr = ["mc", "lhs", "so", "sg", "splitlhs"]
# samplearr = ["lhs","sg","splitlhs"]
# samplearr = ["lhs","splitlhs"]
# samplearr = ["splitlhs"]
from apprentice import tools
from pyDOE import lhs
import apprentice
ts = 2
farr = getfarr()
for fname in farr:
dim = getdim(fname)
minarr, maxarr = getbox(fname)
npoints = ts * tools.numCoeffsRapp(dim, [int(m), int(n)])
print(npoints)
for sample in samplearr:
for numex, ex in enumerate(
["exp1", "exp2", "exp3", "exp4", "exp5"]):
seed = seedarr[numex]
np.random.seed(seed)
if (sample == "mc"):
Xperdim = ()
for d in range(dim):
Xperdim = Xperdim + (np.random.rand(npoints, ) *
(maxarr[d] - minarr[d]) +
minarr[d], )
X = np.column_stack(Xperdim)
formatStr = "{0:0%db}" % (dim)
for d in range(2**dim):
binArr = [int(x) for x in formatStr.format(d)[0:]]
val = []
for i in range(dim):
if (binArr[i] == 0):
val.append(minarr[i])
else:
val.append(maxarr[i])
X[d] = val
elif (sample == "sg"):
from dolo.numeric.interpolation.smolyak import SmolyakGrid
s = 0
l = 1
while (s < npoints):
sg = SmolyakGrid(a=minarr, b=maxarr, l=l)
s = sg.grid.shape[0]
l += 1
X = sg.grid
elif (sample == "so"):
X = my_i4_sobol_generate(dim, npoints, seed)
s = apprentice.Scaler(np.array(X, dtype=np.float64),
a=minarr,
b=maxarr)
X = s.scaledPoints
elif (sample == "lhs"):
X = lhs(dim, samples=npoints, criterion='maximin')
s = apprentice.Scaler(np.array(X, dtype=np.float64),
a=minarr,
b=maxarr)
X = s.scaledPoints
elif (sample == "splitlhs"):
epsarr = []
for d in range(dim):
#epsarr.append((maxarr[d] - minarr[d])/10)
epsarr.append(10**-6)
facepoints = int(
2 *
tools.numCoeffsRapp(dim - 1, [int(m), int(n)]))
insidepoints = int(npoints - facepoints)
Xmain = np.empty([0, dim])
# Generate inside points
minarrinside = []
maxarrinside = []
for d in range(dim):
minarrinside.append(minarr[d] + epsarr[d])
maxarrinside.append(maxarr[d] - epsarr[d])
X = lhs(dim, samples=insidepoints, criterion='maximin')
s = apprentice.Scaler(np.array(X, dtype=np.float64),
a=minarrinside,
b=maxarrinside)
X = s.scaledPoints
Xmain = np.vstack((Xmain, X))
#Generate face points
perfacepoints = int(np.ceil(facepoints / (2 * dim)))
index = 0
for d in range(dim):
for e in [minarr[d], maxarr[d]]:
index += 1
np.random.seed(seed + index * 100)
X = lhs(dim,
samples=perfacepoints,
criterion='maximin')
minarrface = np.empty(shape=dim, dtype=np.float64)
maxarrface = np.empty(shape=dim, dtype=np.float64)
for p in range(dim):
if (p == d):
if e == maxarr[d]:
minarrface[p] = e - epsarr[d]
maxarrface[p] = e
else:
minarrface[p] = e
maxarrface[p] = e + epsarr[d]
else:
minarrface[p] = minarr[p]
maxarrface[p] = maxarr[p]
s = apprentice.Scaler(np.array(X,
dtype=np.float64),
a=minarrface,
b=maxarrface)
X = s.scaledPoints
Xmain = np.vstack((Xmain, X))
Xmain = np.unique(Xmain, axis=0)
X = Xmain
formatStr = "{0:0%db}" % (dim)
for d in range(2**dim):
binArr = [int(x) for x in formatStr.format(d)[0:]]
val = []
for i in range(dim):
if (binArr[i] == 0):
val.append(minarr[i])
else:
val.append(maxarr[i])
X[d] = val
if not os.path.exists(folder + "/" + ex + '/benchmarkdata'):
os.makedirs(folder + "/" + ex + '/benchmarkdata',
exist_ok=True)
for noise in ["0", "10-2", "10-4", "10-6"]:
noisestr, noisepct = getnoiseinfo(noise)
Y = getData(X, fn=fname, noisepct=noisepct, seed=seed)
outfile = "%s/%s/benchmarkdata/%s%s_%s.txt" % (
folder, ex, fname, noisestr, sample)
print(outfile)
np.savetxt(outfile, np.hstack((X, Y.T)), delimiter=",")
if (sample == "sg"):
break
def time_iteration(model,
bounds=None,
verbose=False,
initial_dr=None,
pert_order=1,
with_complementarities=True,
interp_type='smolyak',
smolyak_order=3,
interp_orders=None,
maxit=500,
tol=1e-8,
integration='gauss-hermite',
integration_orders=None,
T=200,
n_s=3,
hook=None):
"""Finds a global solution for ``model`` using backward time-iteration.
Parameters:
-----------
model: NumericModel
"fg" or "fga" model to be solved
bounds: ndarray
boundaries for approximations. First row contains minimum values. Second row contains maximum values.
verbose: boolean
if True, display iterations
initial_dr: decision rule
initial guess for the decision rule
pert_order: {1}
if no initial guess is supplied, the perturbation solution at order ``pert_order`` is used as initial guess
with_complementarities: boolean (True)
if False, complementarity conditions are ignored
interp_type: {`smolyak`, `spline`}
type of interpolation to use for future controls
smolyak_orders: int
parameter ``l`` for Smolyak interpolation
interp_orders: 1d array-like
list of integers specifying the number of nods in each dimension if ``interp_type="spline" ``
Returns:
--------
decision rule object (SmolyakGrid or MultivariateSplines)
"""
def vprint(t):
if verbose:
print(t)
parms = model.calibration['parameters']
sigma = model.covariances
if initial_dr == None:
if pert_order == 1:
from dolo.algos.perturbations import approximate_controls
initial_dr = approximate_controls(model)
if pert_order > 1:
raise Exception("Perturbation order > 1 not supported (yet).")
if interp_type == 'perturbations':
return initial_dr
if bounds is not None:
pass
elif model.options and 'approximation_space' in model.options:
vprint('Using bounds specified by model')
approx = model.options['approximation_space']
a = approx['a']
b = approx['b']
bounds = numpy.row_stack([a, b])
bounds = numpy.array(bounds, dtype=float)
else:
vprint('Using asymptotic bounds given by first order solution.')
from dolo.numeric.timeseries import asymptotic_variance
# this will work only if initial_dr is a Taylor expansion
Q = asymptotic_variance(initial_dr.A.real,
initial_dr.B.real,
initial_dr.sigma,
T=T)
devs = numpy.sqrt(numpy.diag(Q))
bounds = numpy.row_stack([
initial_dr.S_bar - devs * n_s,
initial_dr.S_bar + devs * n_s,
])
if interp_orders == None:
interp_orders = [5] * bounds.shape[1]
if interp_type == 'smolyak':
from dolo.numeric.interpolation.smolyak import SmolyakGrid
dr = SmolyakGrid(bounds[0, :], bounds[1, :], smolyak_order)
elif interp_type == 'spline':
from dolo.numeric.interpolation.splines import MultivariateSplines
dr = MultivariateSplines(bounds[0, :], bounds[1, :], interp_orders)
elif interp_type == 'multilinear':
from dolo.numeric.interpolation.multilinear import MultilinearInterpolator
dr = MultilinearInterpolator(bounds[0, :], bounds[1, :], interp_orders)
if integration == 'optimal_quantization':
from dolo.numeric.discretization import quantization_nodes
# number of shocks
[epsilons, weights] = quantization_nodes(N_e, sigma)
elif integration == 'gauss-hermite':
from dolo.numeric.discretization import gauss_hermite_nodes
if not integration_orders:
integration_orders = [3] * sigma.shape[0]
[epsilons, weights] = gauss_hermite_nodes(integration_orders, sigma)
vprint('Starting time iteration')
# TODO: transpose
grid = dr.grid
xinit = initial_dr(grid)
xinit = xinit.real # just in case...
from dolo.algos.convert import get_fg_functions
f, g = get_fg_functions(model)
import time
fun = lambda x: step_residual(grid, x, dr, f, g, parms, epsilons, weights)
##
t1 = time.time()
err = 1
x0 = xinit
it = 0
verbit = True if verbose == 'full' else False
if with_complementarities:
lbfun = model.functions['arbitrage_lb']
ubfun = model.functions['arbitrage_ub']
lb = lbfun(grid, parms)
ub = ubfun(grid, parms)
else:
lb = None
ub = None
if verbose:
headline = '|{0:^4} | {1:10} | {2:8} | {3:8} | {4:3} |'.format(
'N', ' Error', 'Gain', 'Time', 'nit')
stars = '-' * len(headline)
print(stars)
print(headline)
print(stars)
err_0 = 1
while err > tol and it < maxit:
t_start = time.time()
it += 1
dr.set_values(x0)
from dolo.numeric.optimize.newton import serial_newton, SerialDifferentiableFunction
from dolo.numeric.optimize.ncpsolve import ncpsolve
sdfun = SerialDifferentiableFunction(fun)
if with_complementarities:
[x, nit] = ncpsolve(sdfun, lb, ub, x0, verbose=verbit)
else:
[x, nit] = serial_newton(sdfun, x0, verbose=verbit)
err = abs(x - x0).max()
err_SA = err / err_0
err_0 = err
t_finish = time.time()
elapsed = t_finish - t_start
if verbose:
print('|{0:4} | {1:10.3e} | {2:8.3f} | {3:8.3f} | {4:3} |'.format(
it, err, err_SA, elapsed, nit))
x0 = x0 + (x - x0)
if hook:
hook(dr, it, err)
if False in np.isfinite(x0):
print('iteration {} failed : non finite value')
return [x0, x]
if it == maxit:
import warnings
warnings.warn(UserWarning("Maximum number of iterations reached"))
t2 = time.time()
if verbose:
print(stars)
print('Elapsed: {} seconds.'.format(t2 - t1))
print(stars)
return dr