Beispiel #1
0
def demslv07():
    """Linear complementarity problem methods    """

    # Generate problem test data
    n = 8
    z = np.random.randn(n, 2) - 1
    a = np.min(z, 1)
    b = np.max(z, 1)
    q = np.random.randn(n)
    M = np.random.randn(n, n)
    M = -np.dot(M.T, M)
    x0 = np.random.randn(n)

    # Define the problem by creating an MCP object
    L = MCP(M, a, b, q, showiters=True)

    # Solve my applying Newton method to semi-smooth formulation
    t1 = tic()
    x1, z1 = L.zero(x0)
    t1 = toc(t1)

    # Solve my applying Newton method to minmax formulation
    t2 = tic()
    x2, z2 = L.zero(x0, transform='minmax')
    t2 = toc(t2)

    # Print results
    G = lambda x, z: norm(minmax(x, a, b, z))

    print('Hundreds of seconds required to solve randomly generated linear \n',
          'complementarity problem on R^8 using Newton and Lemke methods')
    print('\nAlgorithm           Time      Norm \n{}'.format('-' * 40))
    print('Newton semismooth {:6.2f}  {:8.0e}'.format(100 * t1, G(x1, z1)))
    print('Newton minmax     {:6.2f}  {:8.0e}'.format(100 * t2, G(x2, z2)))
Beispiel #2
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def demslv08():
    """Nonlinear complementarity problem methods

    Solve nonlinear complementarity problem on R^2 using semismooth and minmax methods
    """

    ''' function to be solved'''
    def f(z):
        x, y = z
        fval = np.array([200 * x * (y - x ** 2) + 1 - x,
                         100 * (x ** 2 - y)])
        fjac = np.array([[200 * (y - x ** 2) - 400 * x ** 2 - 1, 200 * x],
                         [200 * x, -100]])

        return fval, fjac

    # Generate problem test data
    z = 2 * np.random.randn(2, 2)
    a = 1 + np.min(z, 0)
    b = 1 + np.max(z, 0)
    x0 = np.random.randn(2)

    hdr = 'Hundreds of seconds required to solve nonlinear complementarity \n' \
          'problem on R^2 using minmax and semismooth formulations, with \n' \
          'randomly generated bounds \n\ta = [{:4.2f}, {:4.2f}] \n\tb = [{:4.2f}, {:4.2f}]'
    print(hdr.format(a[0], a[1], b[0], b[1]))
    print('\nAlgorithm           Time      Norm        x1     x2\n{}'.format('-' * 56));

    # Define the problem
    P = MCP(f, a, b, maxit=1500)

    '''Solve my applying Newton method to minmax formulation '''
    t1 = tic()
    x, z = P.zero(x0, transform='minmax')
    print('Newton minmax     {:6.2f}  {:8.0e}     {:5.2f}  {:5.2f}'.format(100*toc(t1), norm(minmax(x, a, b, z)), *x))



    '''Solve my applying Newton method to semismooth formulation '''
    t2 = tic()
    x, z = P.zero(x0)
    print('Newton semismooth {:6.2f}  {:8.0e}     {:5.2f}  {:5.2f}'.format(100*toc(t2), norm(minmax(x, a, b, z)), *x))
Beispiel #3
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def demslv08():
    """Nonlinear complementarity problem methods

    Solve nonlinear complementarity problem on R^2 using semismooth and minmax methods
    """
    ''' function to be solved'''
    def f(z):
        x, y = z
        fval = np.array([200 * x * (y - x**2) + 1 - x, 100 * (x**2 - y)])
        fjac = np.array([[200 * (y - x**2) - 400 * x**2 - 1, 200 * x],
                         [200 * x, -100]])

        return fval, fjac

    # Generate problem test data
    z = 2 * np.random.randn(2, 2)
    a = 1 + np.min(z, 0)
    b = 1 + np.max(z, 0)
    x0 = np.random.randn(2)

    hdr = 'Hundreds of seconds required to solve nonlinear complementarity \n' \
          'problem on R^2 using minmax and semismooth formulations, with \n' \
          'randomly generated bounds \n\ta = [{:4.2f}, {:4.2f}] \n\tb = [{:4.2f}, {:4.2f}]'
    print(hdr.format(a[0], a[1], b[0], b[1]))
    print('\nAlgorithm           Time      Norm        x1     x2\n{}'.format(
        '-' * 56))

    # Define the problem
    P = MCP(f, a, b, maxit=1500)
    '''Solve my applying Newton method to minmax formulation '''
    t1 = tic()
    x, z = P.zero(x0, transform='minmax')
    print('Newton minmax     {:6.2f}  {:8.0e}     {:5.2f}  {:5.2f}'.format(
        100 * toc(t1), norm(minmax(x, a, b, z)), *x))
    '''Solve my applying Newton method to semismooth formulation '''
    t2 = tic()
    x, z = P.zero(x0)
    print('Newton semismooth {:6.2f}  {:8.0e}     {:5.2f}  {:5.2f}'.format(
        100 * toc(t2), norm(minmax(x, a, b, z)), *x))
Beispiel #4
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def demslv07():
    """Linear complementarity problem methods    """

    # Generate problem test data
    n = 8
    z = np.random.randn(n, 2) - 1
    a = np.min(z, 1)
    b = np.max(z, 1)
    q = np.random.randn(n)
    M = np.random.randn(n, n)
    M = - np.dot(M.T, M)
    x0 = np.random.randn(n)


    # Define the problem by creating an MCP object
    L = MCP(M, a, b, q, showiters=True)

    # Solve my applying Newton method to semi-smooth formulation
    t1 = tic()
    x1, z1 = L.zero(x0)
    t1 = toc(t1)

    # Solve my applying Newton method to minmax formulation
    t2 = tic()
    x2, z2 = L.zero(x0, transform='minmax')
    t2 = toc(t2)


    # Print results
    G = lambda x, z: norm(minmax(x, a, b, z))

    print('Hundreds of seconds required to solve randomly generated linear \n',
          'complementarity problem on R^8 using Newton and Lemke methods')
    print('\nAlgorithm           Time      Norm \n{}'.format('-' * 40))
    print('Newton semismooth {:6.2f}  {:8.0e}'.format(100 * t1, G(x1, z1)))
    print('Newton minmax     {:6.2f}  {:8.0e}'.format(100 * t2, G(x2, z2)))
# ### Set up the problem
# The class **MCP** is used to represent mixed-complementarity problems. To create one instance, we define the objective function and the boundaries $a$ and $b$ such that for $a \leq x \leq b$

# In[3]:

def billups(x):
    fval = 1.01 - (1 - x) ** 2
    fjac = 2 * (1 - x )
    return fval, fjac


a = 0
b = np.inf

Billups = MCP(billups, a, b)


# ### Solve by applying Newton method
# * Using minmax formulation
# Initial guess is $x=0$
Billups.x0 = 0.0


# In[4]:

t1 = tic()
x1 =  Billups.zero(transform='minmax')
t1 = 100*toc(t1)
n1 = Billups.fnorm
Beispiel #6
0
    numB = 2 * egt
    den = (gamma + k) * egt + 2 * gamma
    expA = 2 * k * a / (s**2)
    A = (numA / den)**expA
    B = numB / den
    Z = A * exp(-B * r)
    return Z


def ss(x, r, tau):
    k, a, s = x
    resid = r + 100 * log(Z(r / 100, tau, k, a, s)) / tau
    return -(resid**2).sum()


def ss2(x, r, tau):
    tmp = lambda x: ss(x, r, tau)
    return jacobian(tmp, x)[0]


x0 = np.array([0.51, 0.05, 0.12])

hola = MCP(ss2, np.zeros(3), np.ones(3), x0, treasury_r[0], treasury_tau)
x = hola.zero(print=True)
print(x)

objective = OP(ss, x0, treasury_r[0], treasury_tau)
objective.qnewton(print=True, all_x=True)
print(objective.x)
print(objective.fnorm)
Beispiel #7
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def demslv09():
    """ Hard nonlinear complementarity problem with Billup's function

     Solve hard nonlinear complementarity problem on R using semismooth and minmax methods.  Problem involves Billup's
     function.  Minmax formulation fails semismooth formulation suceeds.
    """

    warnings.simplefilter("ignore")
    ''' Billups' function'''
    def billups(x):
        fval = 1.01 - (1 - x)**2
        fjac = 2 * (1 - x)
        return fval, fjac

    ''' Set up the problem '''
    # Generate problem test data
    x0 = 0.0
    a = 0
    b = np.inf

    Billups = MCP(billups, a, b)

    # Print table header
    print(
        'Hundreds of seconds required to solve hard nonlinear complementarity')
    print('problem using Newton semismooth and minmax formulations')
    print('Algorithm           Time      Norm         x')

    # Solve by applying Newton method to minmax formulation
    t1 = tic()
    x, z = Billups.zero(x0, transform='minmax')
    t1 = 100 * toc(t1)
    print('Newton minmax     {:6.2f}  {:8.0e}     {:5.2f}'.format(
        t1, norm(minmax(x, a, b, z)), x[0]))

    # Solve by applying Newton method to semismooth formulation
    t2 = tic()
    x, z = Billups.zero(x0)
    t2 = 100 * toc(t2)
    print('Newton semismooth {:6.2f}  {:8.0e}     {:5.2f}'.format(
        t2, norm(minmax(x, a, b, z)), x[0]))
    ''' Make figure '''
    # Minmax reformulation of Billups' function
    billupsm = lambda x: minmax(x, 0, np.inf, billups(x)[0])

    # Semismooth reformulation of Billups' function
    billupss = lambda x: ssmooth(x, 0, np.inf, billups(x)[0])

    fig = plt.figure()

    x = np.linspace(-0.5, 2.5, 500)
    y = Billups.ssmooth(x)
    ax1 = fig.add_subplot(121,
                          title='Difficult NCP',
                          aspect=1,
                          xlabel='x',
                          xlim=[-0.5, 2.5],
                          ylim=[-1, 1.5])
    ax1.axhline(ls='--', color='gray')
    ax1.plot(x, billupss(x), label='Semismooth')
    ax1.plot(x, billupsm(x), label='Minmax')
    ax1.legend(loc='bottom')

    x = np.linspace(-0.03, 0.03, 500)
    ax2 = fig.add_subplot(122,
                          title='Difficult NCP Magnified',
                          aspect=1,
                          xlabel='x',
                          xlim=[-.035, .035],
                          ylim=[-.01, .06])
    ax2.axhline(ls='--', color='gray')
    ax2.plot(x, billupss(x), label='Semismooth')
    ax2.plot(x, billupsm(x), label='Minmax')
    ax2.legend(loc='best')
    plt.show()
Beispiel #8
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x = market.broyden([0.2, 0.2])
print('q1 = ', x[0], '\nq2 = ', x[1])
''' Example page 43 '''
# numbers don't match those of Table 3.1, but CompEcon2014' broyden gives same answer as this code
example(43)
opts = {'maxit': 30, 'all_x': True, 'print': True}

g = NLP(lambda x: sqrt(x), 0.5)
f = NLP(lambda x: (x - sqrt(x), 1 - 0.5 / sqrt(x)), 0.5)

x_fp = g.fixpoint(**opts)
x_br = f.broyden(**opts)
x_nw = f.newton(**opts)
''' Example page 51 '''
example(51)
f = MCP(lambda x: (1.01 - (1 - x)**2, 2 * (1 - x)), 0, np.inf)
x = f.zero(0.0)  # ssmooth transform by default
print('Using', f.opts.transform, 'transformation,  x = ', x)
x = f.zero(0.0, transform='minmax')
print('Using', f.opts.transform, 'transformation, x = ', x,
      'FAILED TO CONVERGE')

# ==============================================================
''' Exercise 3.1 '''
exercise('3.1')


def newtroot(c):
    x = c / 2
    for it in range(150):
        fx = x**2 - c
    A = (numA / den) ** expA
    B = numB / den
    Z = A * exp(-B * r)
    return Z

def ss(x, r, tau):
    k, a, s = x
    resid = r + 100 * log(Z(r / 100, tau, k, a, s)) / tau
    return -(resid ** 2).sum()


def ss2(x, r, tau):
    tmp = lambda x: ss(x, r, tau)
    return jacobian(tmp, x)[0]





x0 = np.array([0.51, 0.05, 0.12])

hola = MCP(ss2, np.zeros(3), np.ones(3), x0, treasury_r[0], treasury_tau)
x = hola.zero(print=True)
print(x)

objective = OP(ss, x0, treasury_r[0], treasury_tau)
objective.qnewton(print=True, all_x=True)
print(objective.x)
print(objective.fnorm)

def f(z):
    x, y = z
    fval = np.array([200 * x * (y - x ** 2) + 1 - x,
                     100 * (x ** 2 - y)])
    fjac = np.array([[200 * (y - x ** 2) - 400 * x ** 2 - 1, 200 * x],
                         [200 * x, -100]])

    return fval, fjac


# * Generate problem test data
z = 2 * np.random.randn(2, 2)
a = 1 + np.min(z, 0)
b = 1 + np.max(z, 0)

F = MCP(f, a, b, maxit=1500)


# ### Solve by applying Newton method
# We'll use a random initial guess $x$

# In[4]:

F.x0 = np.random.randn(2)


''' Check the Jacobian '''
F.check_jacobian()


Beispiel #11
0
def demslv09():
    """ Hard nonlinear complementarity problem with Billup's function

     Solve hard nonlinear complementarity problem on R using semismooth and minmax methods.  Problem involves Billup's
     function.  Minmax formulation fails semismooth formulation suceeds.
    """

    warnings.simplefilter("ignore")

    ''' Billups' function'''
    def billups(x):
        fval = 1.01 - (1 - x) ** 2
        fjac = 2 * (1 - x)
        return fval, fjac

    ''' Set up the problem '''
    # Generate problem test data
    x0 = 0.0
    a = 0
    b = np.inf

    Billups = MCP(billups, a, b)

    # Print table header
    print('Hundreds of seconds required to solve hard nonlinear complementarity')
    print('problem using Newton semismooth and minmax formulations')
    print('Algorithm           Time      Norm         x')


    # Solve by applying Newton method to minmax formulation
    t1 = tic()
    x, z = Billups.zero(x0, transform='minmax')
    t1 = 100 * toc(t1)
    print('Newton minmax     {:6.2f}  {:8.0e}     {:5.2f}'.format(t1, norm(minmax(x, a, b, z)), x[0]))

    # Solve by applying Newton method to semismooth formulation
    t2 = tic()
    x, z = Billups.zero(x0)
    t2 = 100 * toc(t2)
    print('Newton semismooth {:6.2f}  {:8.0e}     {:5.2f}'.format(t2, norm(minmax(x, a, b, z)), x[0]))

    ''' Make figure '''
    # Minmax reformulation of Billups' function
    billupsm = lambda x: minmax(x, 0, np.inf, billups(x)[0])

    # Semismooth reformulation of Billups' function
    billupss = lambda x: ssmooth(x, 0, np.inf, billups(x)[0])




    fig = plt.figure()

    x = np.linspace(-0.5, 2.5, 500)
    y = Billups.ssmooth(x)
    ax1 = fig.add_subplot(121, title='Difficult NCP', aspect=1,
                         xlabel='x', xlim=[-0.5, 2.5], ylim=[-1, 1.5])
    ax1.axhline(ls='--', color='gray')
    ax1.plot(x, billupss(x), label='Semismooth')
    ax1.plot(x, billupsm(x), label='Minmax')
    ax1.legend(loc='bottom')

    x = np.linspace(-0.03, 0.03, 500)
    ax2 = fig.add_subplot(122, title='Difficult NCP Magnified', aspect=1,
                          xlabel='x', xlim = [-.035, .035], ylim=[ -.01, .06])
    ax2.axhline(ls='--', color='gray')
    ax2.plot(x, billupss(x), label='Semismooth')
    ax2.plot(x, billupsm(x), label='Minmax')
    ax2.legend(loc='best')
    plt.show()
def market(x, jac=False):
    quantities = x.reshape((3,3))
    ps = as_ + bs * quantities.sum(0)
    pd = ad - bd * quantities.sum(1)
    ps, pd = np.meshgrid(ps, pd)
    fval = (pd - ps - c).flatten()
    return (fval, None) if jac else fval


# In[4]:


a = np.zeros(9)
b = np.full(9, np.inf)
Market = MCP(market, a, b)


# In[5]:


x0 = np.zeros(9)
x = Market.zero(x0, transform='minmax')


# In[6]:


quantities = x.reshape(3,3)
prices = as_ + bs * quantities.sum(0)
print('Quantities = \n', quantities)
# ### Set up the problem
# The class **MCP** is used to represent mixed-complementarity problems. To create one instance, we define the objective function and the boundaries $a$ and $b$ such that for $a \leq x \leq b$

# In[3]:


def billups(x):
    fval = 1.01 - (1 - x)**2
    fjac = 2 * (1 - x)
    return fval, fjac


a = 0
b = np.inf

Billups = MCP(billups, a, b)

# ### Solve by applying Newton method
# * Using minmax formulation
# Initial guess is $x=0$
Billups.x0 = 0.0

# In[4]:

t1 = tic()
x1 = Billups.zero(transform='minmax')
t1 = 100 * toc(t1)
n1 = Billups.fnorm

# * Using semismooth formulation
Beispiel #14
0
# In[3]:

A = np.array
as_ = A([9, 3, 18])
bs = A([1, 2, 1])
ad = A([42, 54, 51])
bd = A([3, 2, 1])
c = A([[0, 3, 9], [3, 0, 3], [6, 3, 0]])
params = (as_, bs, ad, bd, c)

# In[4]:

a = np.zeros(9)
b = np.full(9, np.inf)
x0 = np.zeros(9)
Market = MCP(market, a, b, x0, *params)

# In[5]:

x = Market.zero(print=True)

print('Function value at solution\n\t', Market.original(x))
print('Lower bound is binding\n\t', Market.a_is_binding)
print('Upper bound is binding\n\t', Market.b_is_binding)
# print(Market.ssmooth(x))
# print(Market.minmax(x))

# In[6]:

quantities = x.reshape(3, 3)
prices = as_ + bs * quantities.sum(0)
Beispiel #15
0
def f(z):
    x, y = z
    fval = np.array([200 * x * (y - x**2) + 1 - x, 100 * (x**2 - y)])
    fjac = np.array([[200 * (y - x**2) - 400 * x**2 - 1, 200 * x],
                     [200 * x, -100]])

    return fval, fjac


# * Generate problem test data
z = 2 * np.random.randn(2, 2)
a = 1 + np.min(z, 0)
b = 1 + np.max(z, 0)

F = MCP(f, a, b, maxit=1500)

# ### Solve by applying Newton method
# We'll use a random initial guess $x$

# In[4]:

F.x0 = np.random.randn(2)
''' Check the Jacobian '''
F.check_jacobian()

# * Using minmax formulation

# In[5]:

t0 = tic()
Beispiel #16
0

def market(x, jac=False):
    quantities = x.reshape((3, 3))
    ps = as_ + bs * quantities.sum(0)
    pd = ad - bd * quantities.sum(1)
    ps, pd = np.meshgrid(ps, pd)
    fval = (pd - ps - c).flatten()
    return (fval, None) if jac else fval


# In[4]:

a = np.zeros(9)
b = np.full(9, np.inf)
Market = MCP(market, a, b)

# In[5]:

x0 = np.zeros(9)
x = Market.zero(x0, transform='minmax')

# In[6]:

quantities = x.reshape(3, 3)
prices = as_ + bs * quantities.sum(0)
print('Quantities = \n', quantities)
print('Prices = \n', prices)
print('Net exports =\n', quantities.sum(0) - quantities.sum(1))

# * In autarky