Ejemplo n.º 1
0
def test_as_constraint():

    from mystic.math.measures import mean, spread

    def mean_constraint(x, target):
        return mean(x) - target

    def range_constraint(x, target):
        return spread(x) - target

    @quadratic_equality(condition=range_constraint, kwds={'target': 5.0})
    @quadratic_equality(condition=mean_constraint, kwds={'target': 5.0})
    def penalty(x):
        return 0.0

    ndim = 3
    constraints = as_constraint(penalty)  #, solver='fmin')
    #XXX: this is expensive to evaluate, as there are nested optimizations

    from numpy import arange
    x = arange(ndim)
    _x = constraints(x)

    assert round(mean(_x)) == 5.0
    assert round(spread(_x)) == 5.0
    assert round(penalty(_x)) == 0.0

    def cost(x):
        return abs(sum(x) - 5.0)

    npop = ndim * 3
    from mystic.solvers import diffev
    y = diffev(cost, x, npop, constraints=constraints, disp=False, gtol=10)

    assert round(mean(y)) == 5.0
    assert round(spread(y)) == 5.0
    assert round(cost(y)) == 5.0 * (ndim - 1)
Ejemplo n.º 2
0
def test_as_constraint():

  from mystic.math.measures import mean, spread
  def mean_constraint(x, target):
    return mean(x) - target

  def range_constraint(x, target):
    return spread(x) - target

  @quadratic_equality(condition=range_constraint, kwds={'target':5.0})
  @quadratic_equality(condition=mean_constraint, kwds={'target':5.0})
  def penalty(x):
    return 0.0

  ndim = 3
  constraints = as_constraint(penalty, solver='fmin')
  #XXX: this is expensive to evaluate, as there are nested optimizations

  from numpy import arange
  x = arange(ndim)
  _x = constraints(x)
  
  assert round(mean(_x)) == 5.0
  assert round(spread(_x)) == 5.0
  assert round(penalty(_x)) == 0.0

  def cost(x):
    return abs(sum(x) - 5.0)

  npop = ndim*3
  from mystic.solvers import diffev
  y = diffev(cost, x, npop, constraints=constraints, disp=False, gtol=10)

  assert round(mean(y)) == 5.0
  assert round(spread(y)) == 5.0
  assert round(cost(y)) == 5.0*(ndim-1)