예제 #1
0
def runme():
    # instantiate the solver
    _solver = NelderMeadSimplexSolver(3)
    lb, ub = [0., 0., 0.], [10., 10., 10.]
    _solver.SetRandomInitialPoints(lb, ub)
    _solver.SetEvaluationLimits(1000)
    # add a monitor stream
    stepmon = VerboseMonitor(1)
    _solver.SetGenerationMonitor(stepmon)
    # configure the bounds
    _solver.SetStrictRanges(lb, ub)
    # configure stop conditions
    term = Or(VTR(), ChangeOverGeneration())
    _solver.SetTermination(term)
    # add a periodic dump to an archive
    tmpfile = 'mysolver.pkl'
    _solver.SetSaveFrequency(10, tmpfile)
    # run the optimizer
    _solver.Solve(rosen)
    # get results
    x = _solver.bestSolution
    y = _solver.bestEnergy
    # load the saved solver
    solver = LoadSolver(tmpfile)
    #os.remove(tmpfile)
    # obligatory check that state is the same
    assert all(x == solver.bestSolution)
    assert y == solver.bestEnergy
    # modify the termination condition
    term = VTR(0.0001)
    solver.SetTermination(term)
    # run the optimizer
    solver.Solve(rosen)
    os.remove(tmpfile)
    # check the solver serializes
    _s = dill.dumps(solver)
    return dill.loads(_s)
예제 #2
0
ndim = len(lb)
maxiter = 10
maxfun = 1e+6


def cost(x):
    ax, bx, c = x
    return (ax)**2 - bx + c


monitor = Monitor()
solver = NelderMeadSimplexSolver(ndim)
solver.SetRandomInitialPoints(min=lb, max=ub)
solver.SetStrictRanges(min=lb, max=ub)
solver.SetEvaluationLimits(maxiter, maxfun)
solver.SetGenerationMonitor(monitor)
solver.Solve(cost)

solved = solver.bestSolution
monitor.info("solved: %s" % solved)

lmon = len(monitor)
assert solver.bestEnergy == monitor.y[-1]
for xs, x in zip(solved, monitor.x[-1]):
    assert xs == x

solver.SetEvaluationLimits(maxiter * 2, maxfun)
solver.SetGenerationMonitor(monitor)
solver.Solve(cost)

assert len(monitor) > lmon
예제 #3
0
    # select parameter bounds constraints
    from numpy import inf
    min_bounds = [0, -1, -300, -1, 0, -1, -100, -inf, -inf]
    max_bounds = [200, 1, 0, 1, 200, 1, 0, inf, inf]

    # configure monitors
    stepmon = VerboseMonitor(100)
    evalmon = Monitor()

    # use Nelder-Mead to solve 8th-order Chebyshev coefficients
    solver = NelderMeadSimplexSolver(ndim)
    solver.SetInitialPoints(x0)
    solver.SetEvaluationLimits(generations=999)
    solver.SetEvaluationMonitor(evalmon)
    solver.SetGenerationMonitor(stepmon)
    solver.SetStrictRanges(min_bounds, max_bounds)
    solver.enable_signal_handler()
    solver.Solve(chebyshev8cost, termination=CRT(1e-4,1e-4), \
                 sigint_callback=plot_solution)
    solution = solver.bestSolution

    # get solved coefficients and Chi-Squared (from solver members)
    iterations = solver.generations
    cost = solver.bestEnergy
    print "Generation %d has best Chi-Squared: %f" % (iterations, cost)
    print "Solved Coefficients:\n %s\n" % poly1d(solver.bestSolution)

    # compare solution with actual 8th-order Chebyshev coefficients
    print "Actual Coefficients:\n %s\n" % poly1d(chebyshev8coeffs)