import numpy as np
[docs]def get_default_keyf(digits=12):
"""
Get the default key function
Parameters
----------
digits : int
The number of digits for floats
Returns
-------
Function :
The default key function
"""
def default_key(vars_int, vars_float):
"""
Default key function
Parameters
----------
vars_int : np.array
The integer variable values, shape: (n_vars_int,)
vars_float : np.array
The float variable values, shape: (n_vars_float,)
Returns
-------
Object :
The key
"""
li = vars_int.tolist() if len(vars_int) else []
tf = tuple(tuple(v.tolist()) for v in np.round(vars_float, digits))
return (tuple(li), tf)
return default_key
[docs]class Memory:
"""
Storage for function results.
Parameters
----------
size : int
The number of maximally stored results
keyf : Function, optional
The memory key function. Parameters:
(vars_int, vars_float), returns key Object
Attributes
----------
max_size : int
The number of maximally stored results
data : dict
The stored data. Key: keyf return type,
Values: tuples (objs, cons)
keyf : Function
The memory key function. Parameters:
(vars_int, vars_float), returns key Object
"""
[docs] def __init__(self, size, keyf=None):
self.max_size = size
self.keyf = keyf if keyf is not None else get_default_keyf()
self.data = {}
[docs] def clear(self):
"""
Clears the memory
"""
self.data = {}
@property
def size(self):
"""
The number of elements currently stored
in memory
Returns
-------
int :
The number of elements currently stored
in memory
"""
return len(self.data)
[docs] def found_individual(self, vars_int, vars_float):
"""
Check if entry is found in memory.
Parameters
----------
vars_int : np.array
The integer variable values, shape: (n_vars_int,)
vars_float : np.array
The float variable values, shape: (n_vars_float,)
Returns
-------
found : bool
True if data is available
"""
key = self.keyf(vars_int, vars_float)
return key in self.data
[docs] def found_population(self, vars_int, vars_float):
"""
Check if entry is found in memory.
Parameters
----------
vars_int : np.array
The integer variable values, shape: (n_pop, n_vars_int)
vars_float : np.array
The float variable values, shape: (n_pop, n_vars_float)
Returns
-------
found : numpy.ndarray of bool
True if data is available, shape: (n_pop,)
"""
n_pop = len(vars_float)
found = np.zeros(n_pop, dtype=bool)
for pi in range(n_pop):
found[pi] = self.found_individual(vars_int[pi], vars_float[pi])
return found
[docs] def store_individual(self, vars_int, vars_float, objs, cons):
"""
Store objs and cons data.
Parameters
----------
vars_int : np.array
The integer variable values, shape: (n_vars_int,)
vars_float : np.array
The float variable values, shape: (n_vars_float,)
objs : np.array
The objective function values, shape: (n_objectives,)
con : np.array
The constraints values, shape: (n_constraints,)
"""
key = self.keyf(vars_int, vars_float)
if key in self.data and self.size == self.max_size:
delk = next(iter(self.dict.keys()))
del self.dict[delk]
self.data[key] = (objs.copy(), cons.copy())
[docs] def store_population(self, vars_int, vars_float, objs, cons):
"""
Store objs and cons data of a population.
Parameters
----------
vars_int : np.array
The integer variable values, shape: (n_pop, n_vars_int)
vars_float : np.array
The float variable values, shape: (n_pop, n_vars_float)
objs : np.array
The objective function values, shape: (n_pop, n_objectives)
con : np.array
The constraints values, shape: (n_pop, n_constraints)
"""
for pi in range(len(objs)):
self.store_individual(vars_int[pi], vars_float[pi], objs[pi], cons[pi])
[docs] def lookup_individual(self, vars_int, vars_float):
"""
Lookup results from memory.
Parameters
----------
vars_int : np.array
The integer variable values, shape: (n_vars_int,)
vars_float : np.array
The float variable values, shape: (n_vars_float,)
Returns
-------
results : tuple or None
The results (objs, cons) if found, None otherwise
"""
key = self.keyf(vars_int, vars_float)
if key not in self.data:
return None
objs, cons = self.data[key]
return objs.copy(), cons.copy()
[docs] def lookup_population(self, vars_int, vars_float, target=None):
"""
Lookup results from memory.
Parameters
----------
vars_int : np.array
The integer variable values, shape: (n_pop, n_vars_int)
vars_float : np.array
The float variable values, shape: (n_pop, n_vars_float)
target : numpy.ndarray, optional
The results array to write to, shape:
(n_pop, n_objs_cmpnts + n_cons_cmpnts)
Returns
-------
results : numpy.ndarray or None
None if no results at all found, otherwise array
with shape: (n_pop, n_objs_cmpnts + n_cons_cmpnts)
"""
results = target
n_pop = len(vars_float)
for pi in range(n_pop):
key = self.keyf(vars_int[pi], vars_float[pi])
if key in self.data:
objs, cons = self.data[key]
if results is None:
n_o = len(objs)
n_c = len(cons)
results = np.full((n_pop, n_o + n_c), np.nan, dtype=objs.dtype)
results[pi] = np.r_[objs, cons]
return results