GPy/GPy/mappings/symbolic.py
2014-04-23 12:19:46 +01:00

57 lines
1.6 KiB
Python

# Copyright (c) 2014 GPy Authors
# Licensed under the BSD 3-clause license (see LICENSE.txt)
import sympy as sym
from ..core.mapping import Mapping, Bijective_mapping
from ..core.symbolic import Symbolic_core
import numpy as np
class Symbolic(Mapping, Symbolic_core):
"""
Symbolic mapping
Mapping where the form of the mapping is provided by a sympy expression.
"""
def __init__(self, input_dim, output_dim, f=None, name='symbolic', parameters=None, func_modules=[]):
if f is None:
raise ValueError, "You must provide an argument for the function."
Mapping.__init__(self, input_dim, output_dim, name=name)
Symbolic_core.__init__(self, {'f': f}, ['X'], derivatives = ['X', 'theta'], parameters=parameters, func_modules=func_modules)
self._initialize_cache()
self.parameters_changed()
def _initialize_cache(self):
self._set_attribute('x_0', np.random.normal(size=(3, self.input_dim)))
def parameters_changed(self):
self.eval_parameters_changed()
def update_cache(self, X=None):
self.eval_update_cache(X=X)
def update_gradients(self, partial, X=None):
for name, val in self.eval_update_gradients('f', partial, X=X).iteritems():
setattr(getattr(self, name), 'gradient', val)
def gradients_X(self, partial, X=None):
return self.eval_gradients_X('f', partial, X=X)
def f(self, X=None):
"""
"""
return self.eval_function('f', X=X)
def df_dX(self, X):
"""
"""
pass
def df_dtheta(self, X):
pass