Merge branch 'params' of github.com:SheffieldML/GPy into params

This commit is contained in:
James Hensman 2014-02-24 08:22:12 +00:00
commit 712be15f6d

View file

@ -1,16 +1,34 @@
import numpy as np
import sympy as sp
from sympy.utilities.codegen import codegen
# Check Matthew Rocklin's blog post.
try:
import sympy as sp
sympy_available=True
except ImportError:
sympy_available=False
exit()
from sympy.core.cache import clear_cache
from scipy import weave
import re
from sympy.utilities.codegen import codegen
try:
from scipy import weave
weave_available = True
except ImportError:
weave_available = False
import os
import sys
current_dir = os.path.dirname(os.path.abspath(os.path.dirname(__file__)))
import sys
import numpy as np
import re
import tempfile
import pdb
import ast
from kernpart import Kernpart
from ...core.parameterization import Param
from ...core.parameterization.transformations import Logexp
# TODO have this set up in a set up file!
user_code_storage = tempfile.gettempdir()
class spkern(Kernpart):
"""
@ -28,96 +46,117 @@ class spkern(Kernpart):
- to handle multpile correlated outputs, you'll need to add parameters with an index, such as lengthscale_i and lengthscale_j.
"""
def __init__(self, input_dim, k=None, output_dim=1, name=None, param=None):
if name is None:
self.name='sympykern'
else:
self.name = name
name='sympykern'
if k is None:
raise ValueError, "You must provide an argument for the covariance function."
super(spkern, self).__init__(input_dim, name)
self._sp_k = k
# pull the variable names out of the symbolic covariance function.
sp_vars = [e for e in k.atoms() if e.is_Symbol]
self._sp_x= sorted([e for e in sp_vars if e.name[0:2]=='x_'],key=lambda x:int(x.name[2:]))
self._sp_z= sorted([e for e in sp_vars if e.name[0:2]=='z_'],key=lambda z:int(z.name[2:]))
# Check that variable names make sense.
assert all([x.name=='x_%i'%i for i,x in enumerate(self._sp_x)])
assert all([z.name=='z_%i'%i for i,z in enumerate(self._sp_z)])
assert len(self._sp_x)==len(self._sp_z)
self.input_dim = len(self._sp_x)
self._real_input_dim = self.input_dim
if output_dim > 1:
self.input_dim += 1
assert self.input_dim == input_dim
x_dim=len(self._sp_x)
# If it is a multi-output covariance, add an input for indexing the outputs.
self._real_input_dim = x_dim
# Check input dim is number of xs + 1 if output_dim is >1
assert self.input_dim == x_dim + int(output_dim > 1)
self.output_dim = output_dim
# extract parameter names
# extract parameter names from the covariance
thetas = sorted([e for e in sp_vars if not (e.name[0:2]=='x_' or e.name[0:2]=='z_')],key=lambda e:e.name)
# Look for parameters with index.
# Look for parameters with index (subscripts), they are associated with different outputs.
if self.output_dim>1:
self._sp_theta_i = sorted([e for e in thetas if (e.name[-2:]=='_i')], key=lambda e:e.name)
self._sp_theta_j = sorted([e for e in thetas if (e.name[-2:]=='_j')], key=lambda e:e.name)
# Make sure parameter appears with both indices!
assert len(self._sp_theta_i)==len(self._sp_theta_j)
assert all([theta_i.name[:-2]==theta_j.name[:-2] for theta_i, theta_j in zip(self._sp_theta_i, self._sp_theta_j)])
# Extract names of shared parameters
# Extract names of shared parameters (those without a subscript)
self._sp_theta = [theta for theta in thetas if theta not in self._sp_theta_i and theta not in self._sp_theta_j]
self.num_split_params = len(self._sp_theta_i)
self._split_theta_names = ["%s"%theta.name[:-2] for theta in self._sp_theta_i]
for theta in self._split_theta_names:
setattr(self, theta, np.ones(self.output_dim))
setattr(self, theta, Param(theta, np.ones(self.output_dim), None))
self.add_parameters(getattr(self, theta))
#setattr(self, theta, np.ones(self.output_dim))
self.num_shared_params = len(self._sp_theta)
self.num_params = self.num_shared_params+self.num_split_params*self.output_dim
#self.num_params = self.num_shared_params+self.num_split_params*self.output_dim
else:
self.num_split_params = 0
self._split_theta_names = []
self._sp_theta = thetas
self.num_shared_params = len(self._sp_theta)
self.num_params = self.num_shared_params
#self.num_params = self.num_shared_params
# Add parameters to the model.
for theta in self._sp_theta:
val = 1.0
if param is not None:
if param.has_key(theta):
val = param[theta]
setattr(self, theta.name, val)
#setattr(self, theta.name, val)
setattr(self, theta.name, Param(theta.name, val, None))
self.add_parameters(getattr(self, theta.name))
#deal with param
self._set_params(self._get_params())
#self._set_params(self._get_params())
#Differentiate!
# Differentiate with respect to parameters.
self._sp_dk_dtheta = [sp.diff(k,theta).simplify() for theta in self._sp_theta]
if self.output_dim > 1:
self._sp_dk_dtheta_i = [sp.diff(k,theta).simplify() for theta in self._sp_theta_i]
# differentiate with respect to input variables.
self._sp_dk_dx = [sp.diff(k,xi).simplify() for xi in self._sp_x]
# psi_stats aren't yet implemented.
if False:
self.compute_psi_stats()
self._code = {}
# generate the code for the covariance functions
self._gen_code()
if False:
extra_compile_args = ['-ftree-vectorize', '-mssse3', '-ftree-vectorizer-verbose=5']
else:
extra_compile_args = []
if weave_available:
if False:
extra_compile_args = ['-ftree-vectorize', '-mssse3', '-ftree-vectorizer-verbose=5']
else:
extra_compile_args = []
self.weave_kwargs = {
'support_code':self._function_code,
'include_dirs':[tempfile.gettempdir(), os.path.join(current_dir,'parts/')],
'headers':['"sympy_helpers.h"'],
'sources':[os.path.join(current_dir,"parts/sympy_helpers.cpp")],
'extra_compile_args':extra_compile_args,
'extra_link_args':['-lgomp'],
'verbose':True}
self.weave_kwargs = {
'support_code': None, #self._function_code,
'include_dirs':[user_code_storage, os.path.join(current_dir,'parts/')],
'headers':['"sympy_helpers.h"', '"'+self.name+'.h"'],
'sources':[os.path.join(current_dir,"parts/sympy_helpers.cpp"), os.path.join(user_code_storage, self.name+'.cpp')],
'extra_compile_args':extra_compile_args,
'extra_link_args':['-lgomp'],
'verbose':True}
self.parameters_changed() # initializes caches
def __add__(self,other):
return spkern(self._sp_k+other._sp_k)
def _gen_code(self):
#generate c functions from sympy objects
argument_sequence = self._sp_x+self._sp_z+self._sp_theta
code_list = [('k',self._sp_k)]
# gradients with respect to covariance input
@ -128,194 +167,268 @@ class spkern(Kernpart):
if self.output_dim > 1:
argument_sequence += self._sp_theta_i + self._sp_theta_j
code_list += [('dk_d%s'%theta.name,dtheta) for theta,dtheta in zip(self._sp_theta_i,self._sp_dk_dtheta_i)]
# generate c functions from sympy objects
if weave_available:
code_type = "C"
else:
code_type = "PYTHON"
# Need to add the sympy_helpers header in here.
(foo_c,self._function_code), (foo_h,self._function_header) = \
codegen(code_list, "C",'foobar',argument_sequence=argument_sequence)
#put the header file where we can find it
f = file(os.path.join(tempfile.gettempdir(),'foobar.h'),'w')
f.write(self._function_header)
codegen(code_list,
code_type,
self.name,
argument_sequence=argument_sequence)
# Use weave to compute the underlying functions.
if weave_available:
# put the header file where we can find it
f = file(os.path.join(user_code_storage, self.name + '.h'),'w')
f.write(self._function_header)
f.close()
if weave_available:
# Substitute any known derivatives which sympy doesn't compute
self._function_code = re.sub('DiracDelta\(.+?,.+?\)','0.0',self._function_code)
# put the cpp file in user code storage (defaults to temp file location)
f = file(os.path.join(user_code_storage, self.name + '.cpp'),'w')
else:
# put the python file in user code storage
f = file(os.path.join(user_code_storage, self.name + '.py'),'w')
f.write(self._function_code)
f.close()
# Substitute any known derivatives which sympy doesn't compute
self._function_code = re.sub('DiracDelta\(.+?,.+?\)','0.0',self._function_code)
if weave_available:
# arg_list will store the arguments required for the C code.
input_arg_list = (["X2(i, %s)"%x.name[2:] for x in self._sp_x]
+ ["Z2(j, %s)"%z.name[2:] for z in self._sp_z])
# This is the basic argument construction for the C code.
#arg_list = (["X[i*input_dim+%s]"%x.name[2:] for x in self._sp_x]
# + ["Z[j*input_dim+%s]"%z.name[2:] for z in self._sp_z])
arg_list = (["X2(i, %s)"%x.name[2:] for x in self._sp_x]
+ ["Z2(j, %s)"%z.name[2:] for z in self._sp_z])
if self.output_dim>1:
reverse_arg_list = list(arg_list)
reverse_arg_list.reverse()
# for multiple outputs reverse argument list is also required
if self.output_dim>1:
reverse_input_arg_list = list(input_arg_list)
reverse_input_arg_list.reverse()
param_arg_list = [shared_params.name for shared_params in self._sp_theta]
arg_list += param_arg_list
# This gives the parameters for the arg list.
param_arg_list = [shared_params.name for shared_params in self._sp_theta]
arg_list = input_arg_list + param_arg_list
precompute_list=[]
if self.output_dim > 1:
reverse_arg_list+=list(param_arg_list)
split_param_arg_list = ["%s1(%s)"%(theta.name[:-2].upper(),index) for index in ['ii', 'jj'] for theta in self._sp_theta_i]
split_param_reverse_arg_list = ["%s1(%s)"%(theta.name[:-2].upper(),index) for index in ['jj', 'ii'] for theta in self._sp_theta_i]
arg_list += split_param_arg_list
reverse_arg_list += split_param_reverse_arg_list
# Extract the right output indices from the inputs.
c_define_output_indices = [' '*16 + "int %s=(int)%s(%s, %i);"%(index, var, index2, self.input_dim-1) for index, var, index2 in zip(['ii', 'jj'], ['X2', 'Z2'], ['i', 'j'])]
precompute_list += c_define_output_indices
reverse_arg_string = ", ".join(reverse_arg_list)
arg_string = ", ".join(arg_list)
precompute_string = "\n".join(precompute_list)
# Here's the code to do the looping for K
self._K_code =\
"""
// _K_code
// Code for computing the covariance function.
int i;
int j;
int N = target_array->dimensions[0];
int num_inducing = target_array->dimensions[1];
int input_dim = X_array->dimensions[1];
//#pragma omp parallel for private(j)
for (i=0;i<N;i++){
for (j=0;j<num_inducing;j++){
%s
//target[i*num_inducing+j] =
TARGET2(i, j) += k(%s);
precompute_list=[]
if self.output_dim > 1:
reverse_arg_list= reverse_input_arg_list + list(param_arg_list)
# For multiple outputs, also need the split parameters.
split_param_arg_list = ["%s1(%s)"%(theta.name[:-2].upper(),index) for index in ['ii', 'jj'] for theta in self._sp_theta_i]
split_param_reverse_arg_list = ["%s1(%s)"%(theta.name[:-2].upper(),index) for index in ['jj', 'ii'] for theta in self._sp_theta_i]
arg_list += split_param_arg_list
reverse_arg_list += split_param_reverse_arg_list
# Extract the right output indices from the inputs.
c_define_output_indices = [' '*16 + "int %s=(int)%s(%s, %i);"%(index, var, index2, self.input_dim-1) for index, var, index2 in zip(['ii', 'jj'], ['X2', 'Z2'], ['i', 'j'])]
precompute_list += c_define_output_indices
reverse_arg_string = ", ".join(reverse_arg_list)
arg_string = ", ".join(arg_list)
precompute_string = "\n".join(precompute_list)
# Now we use the arguments in code that computes the separate parts.
# Any precomputations will be done here eventually.
self._precompute = \
"""
// Precompute code would go here. It will be called when parameters are updated.
"""
# Here's the code to do the looping for K
self._code['K'] =\
"""
// _K_code
// Code for computing the covariance function.
int i;
int j;
int n = target_array->dimensions[0];
int num_inducing = target_array->dimensions[1];
int input_dim = X_array->dimensions[1];
//#pragma omp parallel for private(j)
for (i=0;i<n;i++){
for (j=0;j<num_inducing;j++){
%s
//target[i*num_inducing+j] =
TARGET2(i, j) += k(%s);
}
}
}
%s
"""%(precompute_string,arg_string,"/*"+str(self._sp_k)+"*/") #adding a string representation forces recompile when needed
%s
"""%(precompute_string,arg_string,"/*"+str(self._sp_k)+"*/")
# adding a string representation of the function in the
# comment forces recompile when needed
self._code['K_X'] = self._code['K'].replace('Z2(', 'X2(')
# Code to compute diagonal of covariance.
diag_arg_string = re.sub('Z','X',arg_string)
diag_arg_string = re.sub('int jj','//int jj',diag_arg_string)
diag_arg_string = re.sub('j','i',diag_arg_string)
diag_precompute_string = re.sub('int jj','//int jj',precompute_string)
diag_precompute_string = re.sub('Z','X',diag_precompute_string)
diag_precompute_string = re.sub('j','i',diag_precompute_string)
# Code to do the looping for Kdiag
self._Kdiag_code =\
"""
// _Kdiag_code
// Code for computing diagonal of covariance function.
int i;
int N = target_array->dimensions[0];
int input_dim = X_array->dimensions[1];
//#pragma omp parallel for
for (i=0;i<N;i++){
%s
//target[i] =
TARGET1(i)=k(%s);
}
%s
"""%(diag_precompute_string,diag_arg_string,"/*"+str(self._sp_k)+"*/") #adding a string representation forces recompile when needed
# Code to compute gradients
grad_func_list = []
if self.output_dim>1:
grad_func_list += c_define_output_indices
grad_func_list += [' '*16 + 'TARGET1(%i+ii) += partial[i*num_inducing+j]*dk_d%s(%s);'%(self.num_shared_params+i*self.output_dim, theta.name, arg_string) for i, theta in enumerate(self._sp_theta_i)]
grad_func_list += [' '*16 + 'TARGET1(%i+jj) += partial[i*num_inducing+j]*dk_d%s(%s);'%(self.num_shared_params+i*self.output_dim, theta.name, reverse_arg_string) for i, theta in enumerate(self._sp_theta_i)]
grad_func_list += ([' '*16 + 'TARGET1(%i) += partial[i*num_inducing+j]*dk_d%s(%s);'%(i,theta.name,arg_string) for i,theta in enumerate(self._sp_theta)])
grad_func_string = '\n'.join(grad_func_list)
self._dK_dtheta_code =\
"""
// _dK_dtheta_code
// Code for computing gradient of covariance with respect to parameters.
int i;
int j;
int N = partial_array->dimensions[0];
int num_inducing = partial_array->dimensions[1];
int input_dim = X_array->dimensions[1];
//#pragma omp parallel for private(j)
for (i=0;i<N;i++){
for (j=0;j<num_inducing;j++){
%s
# Code to compute diagonal of covariance.
diag_arg_string = re.sub('Z','X',arg_string)
diag_arg_string = re.sub('int jj','//int jj',diag_arg_string)
diag_arg_string = re.sub('j','i',diag_arg_string)
diag_precompute_string = re.sub('int jj','//int jj',precompute_string)
diag_precompute_string = re.sub('Z','X',diag_precompute_string)
diag_precompute_string = re.sub('j','i',diag_precompute_string)
# Code to do the looping for Kdiag
self._code['Kdiag'] =\
"""
// _code['Kdiag']
// Code for computing diagonal of covariance function.
int i;
int n = target_array->dimensions[0];
int input_dim = X_array->dimensions[1];
//#pragma omp parallel for
for (i=0;i<n;i++){
%s
//target[i] =
TARGET1(i)=k(%s);
}
}
%s
"""%(grad_func_string,"/*"+str(self._sp_k)+"*/") # adding a string representation forces recompile when needed
%s
"""%(diag_precompute_string,diag_arg_string,"/*"+str(self._sp_k)+"*/") #adding a string representation forces recompile when needed
# Code to compute gradients
if self.output_dim>1:
for i, theta in enumerate(self._sp_theta_i):
grad_func_list = [' '*26 + 'TARGET1(ii) += PARTIAL2(i, j)*dk_d%s(%s);'%(theta.name, arg_string)]
grad_func_list += [' '*26 + 'TARGET1(jj) += PARTIAL2(i, j)*dk_d%s(%s);'%(theta.name, reverse_arg_string)]
grad_func_list = c_define_output_indices+grad_func_list
grad_func_string = '\n'.join(grad_func_list)
self._code['dK_d' + theta.name] =\
"""
int i;
int j;
int n = partial_array->dimensions[0];
int num_inducing = partial_array->dimensions[1];
int input_dim = X_array->dimensions[1];
//#pragma omp parallel for private(j)
for (i=0;i<n;i++){
for (j=0;j<num_inducing;j++){
%s
}
}
%s
"""%(grad_func_string,"/*"+str(self._sp_k)+"*/") # adding a string representation forces recompile when needed
self._code['dK_d' +theta.name + '_X'] = self._code['dK_d' + theta.name].replace('Z2(', 'X2(')
# Code to compute gradients for Kdiag TODO: needs clean up
diag_grad_func_string = re.sub('Z','X',grad_func_string,count=0)
diag_grad_func_string = re.sub('int jj','//int jj',diag_grad_func_string)
diag_grad_func_string = re.sub('j','i',diag_grad_func_string)
diag_grad_func_string = re.sub('PARTIAL2\(i, i\)','PARTIAL(i)',diag_grad_func_string)
self._code['dKdiag_d' + theta.name] =\
"""
// _dKdiag_dtheta_code
// Code for computing gradient of diagonal with respect to parameters.
int i;
int n = partial_array->dimensions[0];
int input_dim = X_array->dimensions[1];
for (i=0;i<n;i++){
%s
}
%s
"""%(diag_grad_func_string,"/*"+str(self._sp_k)+"*/") #adding a string representation forces recompile when needed
for i, theta in enumerate(self._sp_theta):
grad_func_list = [' '*26 + 'TARGET1(%i) += PARTIAL2(i, j)*dk_d%s(%s);'%(i,theta.name,arg_string)]
grad_func_string = '\n'.join(grad_func_list)
self._code['dK_d' + theta.name] =\
"""
// _dK_dtheta_code
// Code for computing gradient of covariance with respect to parameters.
int i;
int j;
int n = partial_array->dimensions[0];
int num_inducing = partial_array->dimensions[1];
int input_dim = X_array->dimensions[1];
//#pragma omp parallel for private(j)
for (i=0;i<n;i++){
for (j=0;j<num_inducing;j++){
%s
}
}
%s
"""%(grad_func_string,"/*"+str(self._sp_k)+"*/") # adding a string representation forces recompile when needed
self._code['dK_d' + theta.name +'_X'] = self._code['dK_d' + theta.name].replace('Z2(', 'X2(')
# Code to compute gradients for Kdiag TODO: needs clean up
diag_grad_func_string = re.sub('Z','X',grad_func_string,count=0)
diag_grad_func_string = re.sub('int jj','//int jj',diag_grad_func_string)
diag_grad_func_string = re.sub('j','i',diag_grad_func_string)
diag_grad_func_string = re.sub('PARTIAL2\(i, i\)','PARTIAL(i)',diag_grad_func_string)
self._code['dKdiag_d' + theta.name] =\
"""
// _dKdiag_dtheta_code
// Code for computing gradient of diagonal with respect to parameters.
int i;
int n = partial_array->dimensions[0];
int input_dim = X_array->dimensions[1];
for (i=0;i<n;i++){
%s
}
%s
"""%(diag_grad_func_string,"/*"+str(self._sp_k)+"*/") #adding a string representation forces recompile when needed
# Code to compute gradients for Kdiag TODO: needs clean up
diag_grad_func_string = re.sub('Z','X',grad_func_string,count=0)
diag_grad_func_string = re.sub('int jj','//int jj',diag_grad_func_string)
diag_grad_func_string = re.sub('j','i',diag_grad_func_string)
diag_grad_func_string = re.sub('partial\[i\*num_inducing\+i\]','partial[i]',diag_grad_func_string)
self._dKdiag_dtheta_code =\
"""
// _dKdiag_dtheta_code
// Code for computing gradient of diagonal with respect to parameters.
int i;
int N = partial_array->dimensions[0];
int input_dim = X_array->dimensions[1];
for (i=0;i<N;i++){
# Code for gradients wrt X, TODO: may need to deal with special case where one input is actually an output.
gradX_func_list = []
if self.output_dim>1:
gradX_func_list += c_define_output_indices
gradX_func_list += ["TARGET2(i, %i) += partial[i*num_inducing+j]*dk_dx_%i(%s);"%(q,q,arg_string) for q in range(self._real_input_dim)]
gradX_func_string = "\n".join(gradX_func_list)
self._code['dK_dX'] = \
"""
// _dK_dX_code
// Code for computing gradient of covariance with respect to inputs.
int i;
int j;
int n = partial_array->dimensions[0];
int num_inducing = partial_array->dimensions[1];
int input_dim = X_array->dimensions[1];
//#pragma omp parallel for private(j)
for (i=0;i<n; i++){
for (j=0; j<num_inducing; j++){
%s
}
%s
"""%(diag_grad_func_string,"/*"+str(self._sp_k)+"*/") #adding a string representation forces recompile when needed
# Code for gradients wrt X, TODO: may need to deal with special case where one input is actually an output.
gradX_func_list = []
if self.output_dim>1:
gradX_func_list += c_define_output_indices
gradX_func_list += ["TARGET2(i, %i) += partial[i*num_inducing+j]*dk_dx_%i(%s);"%(q,q,arg_string) for q in range(self._real_input_dim)]
gradX_func_string = "\n".join(gradX_func_list)
self._dK_dX_code = \
"""
// _dK_dX_code
// Code for computing gradient of covariance with respect to inputs.
int i;
int j;
int N = partial_array->dimensions[0];
int num_inducing = partial_array->dimensions[1];
int input_dim = X_array->dimensions[1];
//#pragma omp parallel for private(j)
for (i=0;i<N; i++){
for (j=0; j<num_inducing; j++){
}
}
%s
}
}
%s
"""%(gradX_func_string,"/*"+str(self._sp_k)+"*/") #adding a string representation forces recompile when needed
"""%(gradX_func_string,"/*"+str(self._sp_k)+"*/") #adding a string representation forces recompile when needed
self._code['dK_dX_X'] = self._code['dK_dX'].replace('Z2(', 'X2(')
diag_gradX_func_string = re.sub('Z','X',gradX_func_string,count=0)
diag_gradX_func_string = re.sub('int jj','//int jj',diag_gradX_func_string)
diag_gradX_func_string = re.sub('j','i',diag_gradX_func_string)
diag_gradX_func_string = re.sub('partial\[i\*num_inducing\+i\]','2*partial[i]',diag_gradX_func_string)
# Code for gradients of Kdiag wrt X
self._dKdiag_dX_code= \
"""
// _dKdiag_dX_code
// Code for computing gradient of diagonal with respect to inputs.
int N = partial_array->dimensions[0];
int input_dim = X_array->dimensions[1];
for (int i=0;i<N; i++){
diag_gradX_func_string = re.sub('Z','X',gradX_func_string,count=0)
diag_gradX_func_string = re.sub('int jj','//int jj',diag_gradX_func_string)
diag_gradX_func_string = re.sub('j','i',diag_gradX_func_string)
diag_gradX_func_string = re.sub('PARTIAL2\(i\, i\)','2*PARTIAL(i)',diag_gradX_func_string)
# Code for gradients of Kdiag wrt X
self._code['dKdiag_dX'] = \
"""
// _dKdiag_dX_code
// Code for computing gradient of diagonal with respect to inputs.
int n = partial_array->dimensions[0];
int input_dim = X_array->dimensions[1];
for (int i=0;i<n; i++){
%s
}
%s
}
%s
"""%(diag_gradX_func_string,"/*"+str(self._sp_k)+"*/") #adding a
# string representation forces recompile when needed Get rid
# of Zs in argument for diagonal. TODO: Why wasn't
# diag_func_string called here? Need to check that.
#self._dKdiag_dX_code = self._dKdiag_dX_code.replace('Z[j', 'X[i')
"""%(diag_gradX_func_string,"/*"+str(self._sp_k)+"*/") #adding a
# string representation forces recompile when needed Get rid
# of Zs in argument for diagonal. TODO: Why wasn't
# diag_func_string called here? Need to check that.
# Code to use when only X is provided.
self._K_code_X = self._K_code.replace('Z[', 'X[')
self._dK_dtheta_code_X = self._dK_dtheta_code.replace('Z[', 'X[')
self._dK_dX_code_X = self._dK_dX_code.replace('Z[', 'X[').replace('+= partial[', '+= 2*partial[')
self._K_code_X = self._K_code.replace('Z2(', 'X2(')
self._dK_dtheta_code_X = self._dK_dtheta_code.replace('Z2(', 'X2(')
self._dK_dX_code_X = self._dK_dX_code.replace('Z2(', 'X2(')
#TODO: insert multiple functions here via string manipulation
#TODO: similar functions for psi_stats
def _get_arg_names(self, Z=None, partial=None):
arg_names = ['target','X']
#TODO: insert multiple functions here via string manipulation
#TODO: similar functions for psi_stats
#TODO: similar functions when cython available.
#TODO: similar functions when only python available.
def _get_arg_names(self, target=None, Z=None, partial=None):
arg_names = ['X']
if target is not None:
arg_names += ['target']
for shared_params in self._sp_theta:
arg_names += [shared_params.name]
if Z is not None:
@ -326,45 +439,49 @@ class spkern(Kernpart):
arg_names += self._split_theta_names
arg_names += ['output_dim']
return arg_names
def _weave_inline(self, code, X, target, Z=None, partial=None):
def _generate_inline(self, code, X, target=None, Z=None, partial=None):
output_dim = self.output_dim
# Need to extract parameters to local variables first
for shared_params in self._sp_theta:
locals()[shared_params.name] = getattr(self, shared_params.name)
# Need to extract parameters first
for split_params in self._split_theta_names:
locals()[split_params] = getattr(self, split_params)
arg_names = self._get_arg_names(Z, partial)
weave.inline(code=code, arg_names=arg_names,**self.weave_kwargs)
locals()[split_params] = np.asarray(getattr(self, split_params))
arg_names = self._get_arg_names(target, Z, partial)
if weave_available:
return weave.inline(code=code, arg_names=arg_names,**self.weave_kwargs)
else:
raise RuntimeError('Weave not available and other variants of sympy covariance not yet implemented')
def K(self,X,Z,target):
if Z is None:
self._weave_inline(self._K_code_X, X, target)
self._generate_inline(self._code['K_X'], X, target)
else:
self._weave_inline(self._K_code, X, target, Z)
self._generate_inline(self._code['K'], X, target, Z)
def Kdiag(self,X,target):
self._weave_inline(self._Kdiag_code, X, target)
self._generate_inline(self._code['Kdiag'], X, target)
def _param_grad_helper(self,partial,X,Z,target):
if Z is None:
self._weave_inline(self._dK_dtheta_code_X, X, target, Z, partial)
self._generate_inline(self._code['dK_dtheta_X'], X, target, Z, partial)
else:
self._weave_inline(self._dK_dtheta_code, X, target, Z, partial)
self._generate_inline(self._code['dK_dtheta'], X, target, Z, partial)
def dKdiag_dtheta(self,partial,X,target):
self._weave_inline(self._dKdiag_dtheta_code, X, target, Z=None, partial=partial)
self._generate_inline(self._code['dKdiag_dtheta'], X, target, Z=None, partial=partial).namelocals()[shared_params.name] = getattr(self, shared_params.name)
def gradients_X(self,partial,X,Z,target):
if Z is None:
self._weave_inline(self._dK_dX_code_X, X, target, Z, partial)
self._generate_inline(self._code['dK_dX_X'], X, target, Z, partial)
else:
self._weave_inline(self._dK_dX_code, X, target, Z, partial)
self._generate_inline(self._code['dK_dX'], X, target, Z, partial)
def dKdiag_dX(self,partial,X,target):
self._weave.inline(self._dKdiag_dX_code, X, target, Z, partial)
self._generate_inline(self._code['dKdiag_dX'], X, target, Z, partial)
def compute_psi_stats(self):
#define some normal distributions
@ -394,30 +511,53 @@ class spkern(Kernpart):
clear_cache()
self._sp_psi2 = self._sp_psi2.simplify()
def parameters_changed(self):
# Reset the caches
self._cache, self._cache2 = np.empty(shape=(2, 1))
self._cache3, self._cache4, self._cache5 = np.empty(shape=(3, 1))
def _set_params(self,param):
assert param.size == (self.num_params)
for i, shared_params in enumerate(self._sp_theta):
setattr(self, shared_params.name, param[i])
if self.output_dim>1:
for i, split_params in enumerate(self._split_theta_names):
start = self.num_shared_params + i*self.output_dim
end = self.num_shared_params + (i+1)*self.output_dim
setattr(self, split_params, param[start:end])
def _get_params(self):
params = np.zeros(0)
def update_gradients_full(self, dL_dK, X):
# Need to extract parameters to local variables first
self._K_computations(X, None)
for shared_params in self._sp_theta:
params = np.hstack((params, getattr(self, shared_params.name)))
if self.output_dim>1:
for split_params in self._split_theta_names:
params = np.hstack((params, getattr(self, split_params).flatten()))
return params
parameter = getattr(self, shared_params.name)
code = self._code['dK_d' + shared_params.name]
setattr(parameter, 'gradient', self._generate_inline(code, X, target=None, Z=None, partial=dL_dK))
for split_params in self._split_theta_names:
parameter = getattr(self, split_params.name)
code = self._code['dK_d' + split_params.name]
setattr(parameter, 'gradient', self._generate_inline(code, X, target=None, Z=None, partial=dL_dK))
def _get_param_names(self):
if self.output_dim>1:
return [x.name for x in self._sp_theta] + [x.name[:-2] + str(i) for x in self._sp_theta_i for i in range(self.output_dim)]
# def update_gradients_sparse(self, dL_dKmm, dL_dKnm, dL_dKdiag, X, Z):
# #contributions from Kdiag
# self.variance.gradient = np.sum(dL_dKdiag)
# #from Knm
# self._K_computations(X, Z)
# self.variance.gradient += np.sum(dL_dKnm * self._K_dvar)
# if self.ARD:
# self.lengthscale.gradient = self._dL_dlengthscales_via_K(dL_dKnm, X, Z)
# else:
# self.lengthscale.gradient = (self.variance / self.lengthscale) * np.sum(self._K_dvar * self._K_dist2 * dL_dKnm)
# #from Kmm
# self._K_computations(Z, None)
# self.variance.gradient += np.sum(dL_dKmm * self._K_dvar)
# if self.ARD:
# self.lengthscale.gradient += self._dL_dlengthscales_via_K(dL_dKmm, Z, None)
# else:
# self.lengthscale.gradient += (self.variance / self.lengthscale) * np.sum(self._K_dvar * self._K_dist2 * dL_dKmm)
#---------------------------------------#
# Precomputations #
#---------------------------------------#
def _K_computations(self, X, Z):
if Z is None:
self._generate_inline(self._precompute, X)
else:
return [x.name for x in self._sp_theta]
self._generate_inline(self._precompute, X, Z=Z)