def handle_sum_or_prod(func, name):
val = convert_mp(func.mp())
iter_var = convert_expr(func.subeq().equality().expr(0))
start = convert_expr(func.subeq().equality().expr(1))
if func.supexpr().expr(): # ^{expr}
end = convert_expr(func.supexpr().expr())
else: # ^atom
end = convert_atom(func.supexpr().atom())
if name == "summation":
return sympy.Sum(val, (iter_var, start, end))
elif name == "product":
return sympy.Product(val, (iter_var, start, end))
def dtft(xn):
"""离散时间傅里叶变换
:Parameters:
- xn: 离散非周期序列，序列只能有1个自变量
:Returns: 频谱密度函数（周期连续信号），自变量为Omega(用W表示)
"""
raise Exception("Can't sum from -oo to oo")
n = tuple(xn.free_symbols)[0]
W = sy.symbols('W')
r = (n, -sy.oo, sy.oo)
xW = sy.Sum(xn * sy.exp(-sy.I * W * n), r)
return xW
def _initialize_functions(self):
"""
Build up the nDimensionssymbolic definitions
"""
# Parameters
nDimensions= self.constants[self.nDimensions]
self.position = sp.Matrix([sp.symbols("r_" + str(i)) for i in range(nDimensions)])
self.r_shift = sp.Matrix([sp.symbols("r_shift" + str(i)) for i in range(nDimensions)])
self.V_off = sp.Matrix([sp.symbols("V_off_" + str(i)) for i in range(nDimensions)])
self.k = sp.Matrix([sp.symbols("k_" + str(i)) for i in range(nDimensions)])
# Function
self.V_dim = 0.5 * sp.matrix_multiply_elementwise(self.k, (
(self.position - self.r_shift).applyfunc(lambda x: x ** 2))) # +self.Voff
self.V_functional = sp.Sum(self.V_dim[self.i, 0], (self.i, 0, self.nDimensions - 1))
def remove_images(expr, var, dt, m1=0, m2=0):
if m2 == 0 and isinstance(m1, tuple) and len(m1) == 2:
# Perhaps should warn that this might be deprecated?
m1, m2 = m1
remove_all = m1 == 0 and m2 == 0
const, expr1 = factor_const(expr, var)
result = sym.S.Zero
terms = expr1.as_ordered_terms()
if len(terms) > 1:
for term in expr1.as_ordered_terms():
result += remove_images(term, var, dt, m1, m2)
return const * result
if not isinstance(expr1, sym.Sum):
return expr
sumsym = expr1.args[1].args[0]
def query(expr):
return expr.is_Add and expr.has(var) and expr.has(sumsym)
def value(expr):
if not expr.is_Add:
return expr
if not expr.is_polynomial(var) and not expr.as_poly(var).is_linear:
return expr
expr = expr.expand()
a = expr.coeff(var, 1)
b = expr.coeff(var, 0)
if a == 0:
return expr
if b / a != -sumsym / dt:
return expr
return a * var
expr1 = expr1.replace(query, value)
if remove_all:
return const * expr1.args[0]
return const * sym.Sum(expr1.args[0], (sumsym, m1, m2))
def test_energy_weighted_leastnorm():
# Test energy model of weighted least norm.
omega = -5.
for order in range(0, 3):
# Test weighted model.
for weight in np.linspace(0.01, 1., 3):
n_elec = sp.symbols("n_elec")
_, dict_energy, _, expr, alpha, beta = make_symbolic_least_norm_model(
omega, order, weight)
alpha = sp.Sum(alpha, (n_elec, 2, 13)).doit()
beta = sp.Sum(beta, (n_elec, 2, 13)).doit()
weighted = LeastNormGlobalTool(dict_energy,
omega,
order,
weight,
eps=1e-9)
actual = [weighted.energy(n_elec) for n_elec in range(1, 20)]
desired = [
expr[0].subs([("n_elec", n_elec), ('alpha', alpha),
('beta', beta)]).evalf()
for n_elec in range(1, 20)
]
assert_almost_equal(actual, desired, decimal=4)
def generic_function(val, deriv=0):
"""
Returns specified derivative of a polynomial series. To be used in the place
of functions for specification of boundary conditions.
Parameters
----------
val : Sympy symbol
The variable of the function: x_b should be used.
deriv : int
The order of the derivative. Default is zero.
"""
x_poly = sp.symbols('x_poly')
polynomial = sp.Sum(a[n] * x_poly**n, (n, 0, n_max))
return sp.diff(polynomial, x_poly, deriv).subs(x_poly, val)
def parametrization( # pylint: disable=too-many-arguments
i: int,
s: sp.Symbol,
pole_position: sp.IndexedBase,
pole_width: sp.IndexedBase,
residue_constant: sp.IndexedBase,
beta_constant: sp.IndexedBase,
n_poles: Union[int, sp.Symbol],
pole_id: Union[int, sp.Symbol],
) -> sp.Expr:
beta = beta_constant[pole_id]
gamma = residue_constant[pole_id, i]
mass = pole_position[pole_id]
width = pole_width[pole_id, i]
parametrization = beta * gamma * mass * width / (mass**2 - s)
return sp.Sum(parametrization, (pole_id, 1, n_poles))
def _initialize_functions(self):
"""
_initialize_functions
converts the symbolic mathematics of sympy to a matrix representation that is compatible
with multi-dimentionality.
"""
self.position = sp.Matrix([
sp.symbols("r_" + str(i))
for i in range(self.constants[self.nDimensions])
])
self.wave_potentials = sp.Matrix([
sp.symbols("V_" + str(i))
for i in range(self.constants[self.nWavePotentials])
])
# Function
self.V_functional = sp.Sum(self.wave_potentials[self.i, 0],
(self.i, 0, self.nWavePotentials - 1))
def process_var(self, subscripts, vars_, var):
subs_ = [subscripts[i] for i in self.subscripts.keys()
if f'_{i}' in var]
if var in self.totals.keys():
total_subs = [i for i in self.subscripts.keys()
if f'_{i}' in var]
other_subs = [i for i in self.subscripts.keys()
if f'_{i}' in var]
diff = [i for i in total_subs if i
not in other_subs]
for d in diff:
m = self.subscripts[d]['count']
var = sp.Sum(var, (d, 1, m))
var = vars_[var[0]]
return var
def idfs(xk, N:int, r:tuple=()):
"""离散傅里叶级数逆运算
:Parameters:
- xk: 离散周期频谱序列，序列只能有1个自变量
- N: 序列最小数字周期
- r: 序列一个周期的范围
:Returns: 原信号序列（离散周期序列），序列自变量为n
"""
k = tuple(xk.free_symbols)[0]
n = sy.symbols('n')
if not r:
r = (k, 0, N-1)
W = sy.exp(sy.I * 2 * sy.pi * k * n / N)
xn = sy.Sum(xk * W, r) / N
return xn
def _calculate_z_transform(self):
z = sympy.symbols('z')
n = sympy.symbols('n')
try:
f = sympy.parsing.sympy_parser.parse_expr(self.line_exp_sample.text())
F = sympy.Sum(f * z ** (-n), (n, 0, sympy.oo)).doit(noconds=True)
while isinstance(F, (sympy.Piecewise, sympy.functions.elementary.piecewise.ExprCondPair)):
F = F.args[0]
except (ValueError, TypeError, SyntaxError) as ex:
error_msg = f'ValueError: invalid expression'
print(ex, error_msg)
QtWidgets.QMessageBox.about(self, 'Error message', error_msg)
return -1
self.label_exp_state_val.setText(str(F))
def parametrization( # pylint: disable=too-many-arguments
i: int,
j: int,
s: sp.Symbol,
pole_position: sp.IndexedBase,
pole_width: sp.IndexedBase,
residue_constant: sp.IndexedBase,
n_poles: Union[int, sp.Symbol],
pole_id: Union[int, sp.Symbol],
) -> sp.Expr:
def residue_function(pole_id: int, i: int) -> sp.Expr:
return residue_constant[pole_id, i] * sp.sqrt(
pole_position[pole_id] * pole_width[pole_id, i])
g_i = residue_function(pole_id, i)
g_j = residue_function(pole_id, j)
parametrization = (g_i * g_j) / (pole_position[pole_id]**2 - s)
return sp.Sum(parametrization, (pole_id, 1, n_poles))
def test_piecewise_simplification():
d2d3_11 = (c * d * TP(x, sp.Piecewise(
(x, sp.Eq(k, 0)),
(0, True))) + c * d * TP(sp.Piecewise(
(x, sp.Eq(k, 0)),
(0, True)), x) + d * TP(1, sp.Piecewise(
(x, sp.Eq(k, 0)),
(0, True))) + d * TP(sp.Piecewise((x, sp.Eq(k, 0)),
(0, True)), 1))
assert texpand(d2d3_11) == 0
expr = sp.Sum(
sp.Piecewise(
(c * TP(xy**k,
y * xy**(k - q - 1) * y) + TP(y * xy**(k - 1),
y * xy**(k - q - 1) * y),
sp.Eq(q, 0)), (0, True)), (q, 0, k - 1))
assert texpand(expr) == 0
def manual_y_computation(weighting_seq, input_signal, T):
logging.info('ŷ(t) = ĝ(t) * u(t)')
g_ = sy.IndexedBase('ĝ')
u = sy.IndexedBase('u')
y_ = sy.Sum(g_[k] * u[T - k], (k, 0, T))
logging.info(f'ŷ({T}) = {y_}')
inter_step = lambda weighting_seq: (y_.doit().subs([
(u[i], u_value) for i, u_value in enumerate(input_signal)
]).subs([(g_[i], g_value) for i, g_value in enumerate(weighting_seq)]))
g_sym = inter_step(map(lambda x: sy.symbols(str(x)), weighting_seq))
logging.info(f'ŷ({T}) = {g_sym}')
g_val = inter_step(weighting_seq)
logging.info(f'ŷ({T}) = {g_val}')
return g_val
def state_forced_response_discrete(a, b, u, show_steps=True):
'''Computes the forced response of the state variables based on the input u.
x_homo = state_trans_matrix * initial_cond
Params:
a (list or sympy Matrix): A list of lists for the rows of the A matrix of the system
b (list or sympy Matrix): A list of lists for the b matrix
u (list,sympy Matrix, or a constant): the input to the system
show_steps (bool, True): Pretty prints the steps of the computation
Returns:
sympy Matrix: the forced response
'''
a = sy.Matrix(a)
b = sy.Matrix(b)
# T is for tau
k, i = sy.symbols('k i')
state_trans_neg = state_transition_matrix_discrete(a,
k - 1 - i,
show_steps=False)
state_trans = state_transition_matrix_discrete(a, k, show_steps=False)
# This is in case the u param is dependant on k, if it is we need to make it
# into an i for the summation below
try:
u = u.replace(k, i)
except:
pass
unevaluated_conv_sum = sy.Sum(state_trans_neg * b * u, (i, 0, k - 1))
forced_resp = unevaluated_conv_sum.doit()
# sympy returns None if the answer is zero
if not forced_resp:
forced_resp = sy.zeros(state_trans.shape[0])
if show_steps:
print("Finding the forced response")
display_steps(a, "A matrix")
display_steps(b, "B matrix")
display_steps(state_trans, "State transition matrix: ")
display_steps(state_trans_neg, "Negative state trans matrix")
display_steps(unevaluated_conv_sum, "The convolution summation")
display_steps(forced_resp, "Forced response is ")
return forced_resp
def __init__(self,
V_is: t.List[_potential1DCls],
s: float = 1.0,
Eoff_i: t.List[float] = None,
T: float = 298):
"""
:param V_is:
:param s:
:param Eoff_i:
"""
super().__init__(V_is=V_is, s=s, Eoff_i=Eoff_i)
#Sympy Implementation
Eoffis = {"Eoff_" + str(i): Eoff_i[i] for i in range(self.nStates)}
self.statePotentials = {
"state_" + str(j): V_is[j]
for j in range(self.nStates)
}
self.states = sp.Matrix([
sp.symbols(j) - sp.symbols(k)
for j, k in zip(self.statePotentials, Eoffis)
])
self.constants = {
**{
state: value.V
for state, value in self.statePotentials.items()
},
**Eoffis,
**{
"s": s,
self.T: T,
self.N: self.nStates
}
}
self.V_orig = -1 / (self.beta * self.s_s) * sp.log(
sp.Sum(sp.exp(-self.beta * self.s_s * (self.states[self.i, 0])),
(self.i, 0, self.N - 1)))
self.V = self.V_orig.subs(self.constants)
self.dVdpos = sp.diff(self.V, self.position)
def func(self, expr, n, z):
if not isinstance(expr, AppliedUndef):
self.error('Expecting function')
scale, shift = scale_shift(expr.args[0], n)
# Convert v(n) to V(z), etc.
name = expr.func.__name__
func = sym.Function(name[0].upper() + name[1:])
if not scale.is_constant():
self.error('Cannot determine if time-expansion or decimation')
if scale == 1:
result = func(z)
if shift != 0:
result = result * z ** shift
return result
if scale.is_integer:
# Down-sampling produces aliasing
# Sum(X(z**(1 / M) * exp(-j * 2 * pi * m / M), (m, 0, M - 1)) / M)
# Down-sampling is not shift invariant so z-transform
# is an approximation.
m = self.dummy_var(expr, 'm', level=0, real=True)
expr = func(z**(1 / scale) *
sym.exp(-sym.I * 2 * sym.pi * m / scale))
return sym.Sum(expr, (m, 0, scale - 1)) / scale
if not scale.is_rational:
self.error('Cannot handle arbitrary scaling')
if scale.p != 1:
self.error('Cannot handle non-integer time-expansion')
result = func(z ** scale.q)
if shift != 0:
result = result * z ** shift
return result
def _initialize_functions(self):
# Parameters
nDim = self.constants[self.nDim]
self.position = sp.Matrix(
[sp.symbols("pos_" + str(i)) for i in range(nDim)])
self.multiplicity = sp.Matrix(
[sp.symbols("mult_" + str(i)) for i in range(nDim)])
self.phase_shift = sp.Matrix(
[sp.symbols("phase_" + str(i)) for i in range(nDim)])
self.amplitude = sp.Matrix(
[sp.symbols("amp_" + str(i)) for i in range(nDim)])
self.yOffset = sp.Matrix(
[sp.symbols("yOff_" + str(i)) for i in range(nDim)])
#Function
self.V_dim = sp.matrix_multiply_elementwise(
self.amplitude, (sp.matrix_multiply_elementwise(
(self.position + self.phase_shift),
self.multiplicity)).applyfunc(sp.cos)) + self.yOffset
self.V_orig = sp.Sum(self.V_dim[self.i, 0], (self.i, 0, self.nDim - 1))
def duration(self) -> ExpressionScalar:
step_size = self._loop_range.step.sympified_expression
loop_index = sympy.symbols(self._loop_index)
sum_index = sympy.symbols(self._loop_index)
# replace loop_index with sum_index dependable expression
body_duration = self.body.duration.sympified_expression.subs({loop_index: self._loop_range.start.sympified_expression + sum_index*step_size})
# number of sum contributions
step_count = sympy.ceiling((self._loop_range.stop.sympified_expression-self._loop_range.start.sympified_expression) / step_size)
sum_start = 0
sum_stop = sum_start + (sympy.functions.Max(step_count, 1) - 1)
# expression used if step_count >= 0
finite_duration_expression = sympy.Sum(body_duration, (sum_index, sum_start, sum_stop))
duration_expression = sympy.Piecewise((0, step_count <= 0),
(finite_duration_expression, True))
return ExpressionScalar(duration_expression)
def match_transform(v):
if not isinstance(v, sp.Add):
return None
terms = v.args
coeffs_to_terms = split_coefficients_into_dict_keys(terms)
was_update = False
new_terms = []
for (coeff, terms) in coeffs_to_terms.items():
sums, not_sums = separate_sums(terms)
for i1 in range(len(sums)):
for i2 in range(len(sums)):
if i1 == i2:
continue
sum1 = sums[i1]
sum2 = sums[i2]
func1 = sum1.function
func2 = sum2.function
var1 = sum1.limits[0][0]
var2 = sum2.limits[0][0]
if func1.subs(var1, var2 + 1) == func2:
# match!
was_update = True
new_func = func1.subs(var1, var2)
new_limits = (var2, sum2.limits[0][1] + 1,
sum2.limits[0][2] + 1)
sums[i2] = sp.Sum(new_func, new_limits)
new_terms.extend([coeff * term for term in not_sums + sums])
if was_update:
return sp.Add(*new_terms)
else:
return None
def setWeierstrassFunction(self):
#Example of how to define and set a problem using the parameter class.
self.p_initialPopulation = 50
self.p_populationCap = 50
self.p_specimensPruned = 45
self.p_mutationRate = 0.001
self.p_basisFunction = (a * x)
self.p_targetFitness = 0
self.p_problemVars = [x1]
self.p_problemDomain = [(-2, 2)]
self.p_objectiveFunction = sp.Sum(0.9**n * sp.cos(7**n * np.pi * x1),
(n, self.p_problemDomain[0][0],
self.p_problemDomain[0][1])).doit()
self.p_constraints = []
self.p_fitnessSamples = 101
self.p_maxOrder = 3
self.p_maxStages = 4
self.p_fitnessFunc = fixedDomainCorrelationAndMeanSquareFitness
self.p_reproductionMethod = cellularMethodVariableTermMutation
def _initialize_functions(self):
# for sympy Sympy Updates - Check!:
self.statePotentials = {"state_" + str(j): self.V_is[j] for j in range(self.constants[self.nStates])}
Eoffis = {"Eoff_" + str(i): self.Eoff_i[i] for i in range(self.constants[self.nStates])}
sis = {"s_" + str(i): self.s_i[i] for i in range(self.constants[self.nStates])}
lamis = {"lam_" + str(i): self.lam_i[i] for i in range(self.constants[self.nStates])}
keys = zip(sorted(self.statePotentials.keys()), sorted(Eoffis.keys()), sorted(sis.keys()))
self.states = sp.Matrix([sp.symbols(l) * (sp.symbols(j) - sp.symbols(k)) for j, k, l in keys])
self.constants.update(
{**{state: value.V for state, value in self.statePotentials.items()}, **Eoffis, **sis, **lamis})
inner_log = sp.Sum(sp.Matrix(list(lamis.keys()))[self.i, 0] * sp.exp(-self.beta * self.states[self.i, 0]),
(self.i, 0, self.nStates - 1))
self.V_functional = -1 / (self.beta * self.sis[0, 0]) * sp.log(inner_log)
self._update_functions()
# also make sure that states are up to work:
[V._update_functions() for V in self.V_is]
self.ene = self._calculate_energies_singlePos_overwrite
self.force = self._calculate_dvdpos_singlePos_overwrite
def _initialize_functions(self):
"""
_initialize_functions
converts the symbolic mathematics of sympy to a matrix representation that is compatible
with multi-dimentionality.
"""
# Parameters
nDimensions = self.constants[self.nDimensions]
self.position = sp.Matrix(
[sp.symbols("r_" + str(i)) for i in range(nDimensions)])
self.r_shift = sp.Matrix(
[sp.symbols("r_shift" + str(i)) for i in range(nDimensions)])
self.V_off = sp.Matrix(
[sp.symbols("V_off_" + str(i)) for i in range(nDimensions)])
self.k = sp.Matrix(
[sp.symbols("k_" + str(i)) for i in range(nDimensions)])
# Function
self.V_dim = 0.5 * sp.matrix_multiply_elementwise(
self.k, ((self.position -
self.r_shift).applyfunc(lambda x: x**2))) # +self.Voff
self.V_functional = sp.Sum(self.V_dim[self.i, 0],
(self.i, 0, self.nDimensions - 1))
def __init__(self, wavePotentials):
'''
initializes torsions Potential
'''
self.constants = {
**{
"wave_" + str(key): wave.V
for key, wave in enumerate(wavePotentials)
},
**{
self.N: len(wavePotentials) - 1
}
}
self.wavePotentials = sp.Matrix(
[sp.symbols("wave_" + str(i)) for i in range(len(wavePotentials))])
self.V_orig = sp.Sum(self.wavePotentials[self.i, 0],
(self.i, 0, self.N))
self.V = self.V_orig.subs(self.constants).subs(self.N,
len(wavePotentials))
super().__init__()
def handle_sum_or_prod(func, name):
val = convert_mp(func.mp())
iter_var = None
start = None
if func.subeq(): # e.g. _{i=0}
iter_var = convert_expr(func.subeq().equality().expr(0))
start = convert_expr(func.subeq().equality().expr(1))
elif func.subexpr().expr(): # _{expr}
iter_var = convert_expr(func.subexpr().expr())
else: # _atom
iter_var = convert_atom(func.subexpr().atom())
if func.supexpr():
if func.supexpr().expr(): # ^{expr}
end = convert_expr(func.supexpr().expr())
else: # ^atom
end = convert_atom(func.supexpr().atom())
if name == "summation":
if start is not None:
return sympy.Sum(val, (iter_var, start, end))
else:
return sympy.Function('sum_{' + str(iter_var) + '}')(val)
elif name == "product":
return sympy.Product(val, (iter_var, start, end))
def calculator(pool, var_node):
"""
Symbolically sums the expression of the node.
:return: a lambda expression that substitutes the given lower- and upper bound in the sum
"""
variable, node_id = var_node
expression = pool.get_node(node_id).expression
variables = {str(v): v for v in expression.free_symbols}
if len(variables) == 0:
return lambda lb, ub: (ub - lb + 1) * float(expression)
v = variables[variable] if variable in variables else sympy.S(variable)
# TODO add caching again
try:
# expression = sympy.expand(expression)
# print("Value at r=10 is {}".format(expression.subs({"r": 10})))
result = sympy.Sum(expression, (v, self.lb, self.ub)).doit()
# print("Symbolic sum of {} = {}".format(expression, result))
return lambda lb, ub: result.subs({self.lb: lb, self.ub: ub})
except sympy.BasePolynomialError as e:
print("Problem trying to sum the expression {} for variable {}"
.format(expression, v))
raise e
def integral(self) -> Dict[ChannelID, ExpressionScalar]:
step_size = self._loop_range.step.sympified_expression
loop_index = sympy.symbols(self._loop_index)
sum_index = sympy.symbols(self._loop_index)
body_integrals = self.body.integral
body_integrals = {
c: body_integrals[c].sympified_expression.subs(
{loop_index: self._loop_range.start.sympified_expression + sum_index*step_size}
)
for c in body_integrals
}
# number of sum contributions
step_count = sympy.ceiling((self._loop_range.stop.sympified_expression-self._loop_range.start.sympified_expression) / step_size)
sum_start = 0
sum_stop = sum_start + (sympy.functions.Max(step_count, 1) - 1)
for c in body_integrals:
channel_integral_expr = sympy.Sum(body_integrals[c], (sum_index, sum_start, sum_stop))
body_integrals[c] = ExpressionScalar(channel_integral_expr)
return body_integrals
def test_sum():
sum = sympy.Sum(k, (k, 1, 100))
expanded_sum = sum.doit()
print(sum)
print(expanded_sum)
x = pystencils.fields('x: float32[1d]')
assignments = pystencils.AssignmentCollection({x.center(): sum})
ast = pystencils.create_kernel(assignments)
code = str(pystencils.show_code(ast))
kernel = ast.compile()
print(code)
assert 'double sum' in code
array = np.zeros((10, ), np.float32)
kernel(x=array)
assert np.allclose(array, int(expanded_sum) * np.ones_like(array))
class envelopedPotential(_potentialNDCls):
"""
This implementation of exponential Coupling for EDS is a more numeric robust and variable implementation, it allows N states.
Therefore the computation of energies and the deviation is not symbolic.
Here N-states are coupled by the log-sum-exp resulting in a new reference state $V_R$,
$V_R = -1/{\beta} * \ln(\sum_i^Ne^(-\beta*s*(V_i-E^R_i)))$
This potential coupling is for example used in EDS.
"""
name = "Enveloping Potential"
T, kb, position = sp.symbols("T kb r")
beta = 1 / (kb * T)
Vis = sp.Matrix(["V_i"])
Eoffis = sp.Matrix(["Eoff_i"])
sis = sp.Matrix(["s_i"])
i, nStates = sp.symbols("i N")
V_functional = -1 / (beta * sis[0, 0]) * sp.log(
sp.Sum(sp.exp(-beta * sis[i, 0] * (Vis[i, 0] - Eoffis[i, 0])), (i, 0, nStates)))
def __init__(self, V_is: t.List[_potentialNDCls] = (
harmonicOscillatorPotential(nDimensions=2), harmonicOscillatorPotential(r_shift=[3,3], nDimensions=2)),
s: float = 1.0, eoff: t.List[float] = None, T: float = 1, kb: float = 1):
"""
__init__
This function constructs a enveloped potential, enveloping all given states.
Parameters
----------
V_is: List[_potential1DCls], optional
The states(potential classes) to be enveloped (default: [harmonicOscillatorPotential(), harmonicOscillatorPotential(x_shift=3)])
s: float, optional
the smoothing parameter, lowering the barriers between the states
eoff: List[float], optional
the energy offsets of the individual states in the reference potential. These can be used to allow a more uniform sampling. (default: seta ll to 0)
T: float, optional
the temperature of the reference state (default: 1 = T)
kb: float, optional
the boltzman constant (default: 1 = kb)
"""
self.constants = {self.T: T, self.kb: kb}
nStates = len(V_is)
self._Eoff_i = [0 for x in range(nStates)]
self._s = [0 for x in range(nStates)]
self._V_is = [0 for x in range(nStates)]
# for calculate implementations
self.V_is = V_is
self.s_i = s
self.Eoff_i = eoff
super().__init__(nDimensions=V_is[0].constants[V_is[0].nDimensions], nStates=len(V_is))
def _initialize_functions(self):
"""
build the symbolic functionality.
"""
# for sympy Sympy Updates - Check!:
self.statePotentials = {"state_" + str(j): self.V_is[j] for j in range(self.constants[self.nStates])}
Eoffis = {"Eoff_" + str(i): self.Eoff_i[i] for i in range(self.constants[self.nStates])}
sis = {"s_" + str(i): self.s_i[i] for i in range(self.constants[self.nStates])}
keys = zip(sorted(self.statePotentials.keys()), sorted(Eoffis.keys()), sorted(sis.keys()))
self.states = sp.Matrix([sp.symbols(l) * (sp.symbols(j) - sp.symbols(k)) for j, k, l in keys])
self.constants.update({**{state: value.V for state, value in self.statePotentials.items()}, **Eoffis, **sis})
self.V_functional = -1 / (self.beta * self.sis[0, 0]) * sp.log(
sp.Sum(sp.exp(-self.beta * self.states[self.i, 0]), (self.i, 0, self.nStates - 1)))
self._update_functions()
# also make sure that states are up to work:
[V._update_functions() for V in self.V_is]
if (all([self.s_i[0] == s for s in self.s_i[1:]])):
self.ene = self._calculate_energies_singlePos_overwrite_oneS
else:
self.ene = self._calculate_energies_singlePos_overwrite_multiS
self.force = self._calculate_dvdpos_singlePos_overwrite
@property
def V_is(self) -> t.List[_potentialNDCls]:
"""
V_is are the state potential classes enveloped by the reference state.
Returns
-------
V_is: t.List[_potential1DCls]
"""
return self._V_is
@V_is.setter
def V_is(self, V_is: t.List[_potentialNDCls]):
if (isinstance(V_is, Iterable) and all([isinstance(Vi, _potentialNDCls) for Vi in V_is])):
self._V_is = V_is
self.constants.update({self.nStates: len(V_is)})
else:
raise IOError("Please give the enveloped potential for V_is only 1D-Potential classes in a list.")
def set_Eoff(self, Eoff: Union[Number, Iterable[Number]]):
"""
This function is setting the Energy offsets of the states enveloped by the reference state.
Parameters
----------
Eoff: Union[Number, Iterable[Number]]
"""
self.Eoff_i = Eoff
@property
def Eoff(self) -> t.List[Number]:
"""
The Energy offsets are used to bias the single states in the reference potential by a constant offset.
Therefore each state of the enveloping potential has its own energy offset.
Returns
-------
Eoff:t.List[Number]
"""
return self.Eoff_i
@Eoff.setter
def Eoff(self, Eoff: Union[Number, Iterable[Number], None]):
self.Eoff_i = Eoff
@property
def Eoff_i(self) -> t.List[Number]:
"""
The Energy offsets are used to bias the single states in the reference potential by a constant offset.
Therefore each state of the enveloping potential has its own energy offset.
Returns
-------
Eoff:t.List[Number]
"""
return self._Eoff_i
@Eoff_i.setter
def Eoff_i(self, Eoff: Union[Number, Iterable[Number], None]):
if (isinstance(Eoff, type(None))):
self._Eoff_i = [0.0 for state in range(self.constants[self.nStates])]
Eoffis = {"Eoff_" + str(i): self.Eoff_i[i] for i in range(self.constants[self.nStates])}
self.constants.update({**Eoffis})
elif (len(Eoff) == self.constants[self.nStates]):
self._Eoff_i = Eoff
Eoffis = {"Eoff_" + str(i): self.Eoff_i[i] for i in range(self.constants[self.nStates])}
self.constants.update({**Eoffis})
else:
raise IOError(
"Energy offset Vector and state potentials don't have the same length!\n states in Eoff " + str(
len(Eoff)) + "\t states in Vi" + str(len(self.V_is)))
def set_s(self, s: Union[Number, Iterable[Number]]):
"""
set_s
is a function used to set an smoothing parameter.
Parameters
----------
s:Union[Number, Iterable[Number]]
Returns
-------
"""
self.s_i = s
@property
def s(self) -> t.List[Number]:
return self.s_i
@s.setter
def s(self, s: Union[Number, Iterable[Number]]):
self.s_i = s
@property
def s_i(self) -> t.List[Number]:
return self._s
@s_i.setter
def s_i(self, s: Union[Number, Iterable[Number]]):
if (isinstance(s, Number)):
self._s = [s for x in range(self.constants[self.nStates])]
sis = {"s_" + str(i): self.s_i[i] for i in range(self.constants[self.nStates])}
self.constants.update({**sis})
elif (len(s) == self.constants[self.nStates]):
self._s = s
sis = {"s_" + str(i): self.s_i[i] for i in range(self.constants[self.nStates])}
self.constants.update({**sis})
else:
raise IOError("s Vector/Number and state potentials don't have the same length!\n states in s " + str(
len(s)) + "\t states in Vi" + str(len(self.V_is)))
self._update_functions()
def _calculate_energies_singlePos_overwrite_multiS(self, positions) -> np.array:
sum_prefactors, _ = self._logsumexp_calc_gromos(positions)
beta = self.constants[self.T] * self.constants[self.kb] # kT - *self.constants[self.T]
Vr = (-1 / (beta)) * sum_prefactors
return np.squeeze(Vr)
def _calculate_energies_singlePos_overwrite_oneS(self, positions) -> np.array:
sum_prefactors, _ = self._logsumexp_calc(positions)
beta = self.constants[self.T] * self.constants[self.kb]
Vr = (-1 / (beta * self.s_i[0])) * sum_prefactors
return np.squeeze(Vr)
def _calculate_dvdpos_singlePos_overwrite(self, positions: (t.Iterable[float])) -> np.array:
"""
Parameters
----------
positions
Returns
-------
"""
positions = np.array(positions, ndmin=2)
# print("Pos: ", position)
V_R_part, V_Is_ene = self._logsumexp_calc_gromos(positions)
V_R_part = np.array(V_R_part, ndmin=2).T
# print("V_R_part: ", V_R_part.shape, V_R_part)
# print("V_I_ene: ",V_Is_ene.shape, V_Is_ene)
V_Is_dhdpos = np.array([-statePot.force(positions) for statePot in self.V_is], ndmin=1).T
# print("V_I_force: ",V_Is_dhdpos.shape, V_Is_dhdpos)
adapt = np.concatenate([V_R_part for s in range(self.constants[self.nStates])], axis=1)
# print("ADAPT: ",adapt.shape, adapt)
scaling = np.exp(V_Is_ene - adapt)
# print("scaling: ", scaling.shape, scaling)
dVdpos_state = np.multiply(scaling,
V_Is_dhdpos) # np.array([(ene/V_R_part) * force for ene, force in zip(V_Is_ene, V_Is_dhdpos)])
# print("state_contributions: ",dVdpos_state.shape, dVdpos_state)
dVdpos = np.sum(dVdpos_state, axis=1)
# print("forces: ",dVdpos.shape, dVdpos)
return np.squeeze(dVdpos)
def _logsumexp_calc(self, position):
prefactors = []
beta = self.constants[self.T] * self.constants[self.kb]
for state in range(self.constants[self.nStates]):
prefactor = np.array(-beta * self.s_i[state] * (self.V_is[state].ene(position) - self.Eoff_i[state]),
ndmin=1).T
prefactors.append(prefactor)
prefactors = np.array(prefactors, ndmin=2).T
from scipy.special import logsumexp
# print("Prefactors", prefactors)
sum_prefactors = logsumexp(prefactors, axis=1)
# print("logexpsum: ", np.squeeze(sum_prefactors))
return np.squeeze(sum_prefactors), np.array(prefactors, ndmin=2).T
def _logsumexp_calc_gromos(self, position):
"""
code from gromos:
Parameters
----------
position
Returns
-------
"""
prefactors = []
beta = self.constants[self.T] * self.constants[self.kb] # kT - *self.constants[self.T]
partA = np.array(-beta * self.s_i[0] * (self.V_is[0].ene(position) - self.Eoff_i[0]), ndmin=1)
partB = np.array(-beta * self.s_i[1] * (self.V_is[1].ene(position) - self.Eoff_i[1]), ndmin=1)
partAB = np.array([partA, partB]).T
log_prefac = 1 + np.exp(np.min(partAB, axis=1) - np.max(partAB, axis=1))
sum_prefactors = np.max(partAB, axis=1) + np.log(log_prefac)
prefactors.append(partA)
prefactors.append(partB)
# more than two states!
for state in range(2, self.constants[self.nStates]):
partN = np.array(-beta * self.s_i[state] * (self.V_is[state].ene(position) - self.Eoff_i[state]), ndmin=1)
prefactors.append(partN)
sum_prefactors = np.max([sum_prefactors, partN], axis=1) + np.log(1 + np.exp(
np.min([sum_prefactors, partN], axis=1) - np.max([sum_prefactors, partN], axis=1)))
# print("prefactors: ", sum_prefactors)
return sum_prefactors, np.array(prefactors, ndmin=2).T
class sumPotentials(_potentialNDCls):
"""
Adds n different potentials.
For adding up wavepotentials, we recommend using the addedwavePotential class.
"""
name: str = "Summed Potential"
position = sp.symbols("r")
potentials: sp.Matrix = sp.Matrix([sp.symbols("V_x")])
nPotentials = sp.symbols("N")
i = sp.symbols("i", cls=sp.Idx)
V_functional = sp.Sum(potentials[i, 0], (i, 0, nPotentials))
def __init__(self, potentials: t.List[_potentialNDCls] = (harmonicOscillatorPotential(), harmonicOscillatorPotential(r_shift=[1,1,1], nDimensions=3))):
"""
__init__
This is the Constructor of an summed Potentials
Parameters
----------
potentials: List[_potential2DCls], optional
it uses the 2D potential class to generate its potential,
default to (wavePotential(), wavePotential(multiplicity=[3, 3]))
"""
if(all([potentials[0].constants[V.nDimensions] == V.constants[V.nDimensions] for V in potentials])):
nDim = potentials[0].constants[potentials[0].nDimensions]
else:
raise ValueError("The potentials don't share the same dimensionality!\n\t"+str([V.constants[V.nDimensions] for V in potentials]))
self.constants = {self.nPotentials: len(potentials)}
self.constants.update({"V_" + str(i): potentials[i].V for i in range(len(potentials))})
super().__init__(nDimensions=nDim)
def _initialize_functions(self):
"""
_initialize_functions
converts the symbolic mathematics of sympy to a matrix representation that is compatible
with multi-dimentionality.
"""
self.position = sp.Matrix([sp.symbols("r_" + str(i)) for i in range(self.constants[self.nDimensions])])
self.potentials = sp.Matrix(
[sp.symbols("V_" + str(i)) for i in range(self.constants[self.nPotentials])])
# Function
self.V_functional = sp.Sum(self.potentials[self.i, 0], (self.i, 0, self.nPotentials - 1))
def __str__(self) -> str:
msg = self.__name__() + "\n"
msg += "\tStates: " + str(self.constants[self.nStates]) + "\n"
msg += "\tDimensions: " + str(self.nDimensions) + "\n"
msg += "\n\tFunctional:\n "
msg += "\t\tV:\t" + str(self.V_functional) + "\n"
msg += "\t\tdVdpos:\t" + str(self.dVdpos_functional) + "\n"
msg += "\n\tSimplified Function\n"
msg += "\t\tV:\t" + str(self.V) + "\n"
msg += "\t\tdVdpos:\t" + str(self.dVdpos) + "\n"
msg += "\n"
return msg
# OVERRIDE
def _update_functions(self):
"""
_update_functions
calculates the current energy and derivative of the energy
"""
super()._update_functions()
self.tmp_Vfunc = self._calculate_energies
self.tmp_dVdpfunc = self._calculate_dVdpos
