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removed sinc

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James Hensman 2014-01-24 10:15:06 +00:00
parent 358cf71e01
commit d2e0b0eefd
1 changed files with 1 additions and 23 deletions
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24
GPy/kern/constructors.py
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@ -292,8 +292,7 @@ except ImportError:
if sympy_available: if sympy_available:
from parts.sympykern import spkern from parts.sympykern import spkern
from sympy.parsing.sympy_parser import parse_expr from sympy.parsing.sympy_parser import parse_expr
from GPy.util.symbolic import sinc
def rbf_sympy(input_dim, ARD=False, variance=1., lengthscale=1.): def rbf_sympy(input_dim, ARD=False, variance=1., lengthscale=1.):
""" """
Radial Basis Function covariance. Radial Basis Function covariance.
@ -337,27 +336,6 @@ if sympy_available:
f = scale_i*scale_j*sp.exp(-dist/(2*(shared_lengthscale**2 + lengthscale_i*lengthscale_j))) f = scale_i*scale_j*sp.exp(-dist/(2*(shared_lengthscale**2 + lengthscale_i*lengthscale_j)))
return kern(input_dim, [spkern(input_dim, f, output_dim=output_dim, name='eq_sympy')]) return kern(input_dim, [spkern(input_dim, f, output_dim=output_dim, name='eq_sympy')])
def sinc(input_dim, ARD=False, variance=1., lengthscale=1.):
"""
TODO: Not clear why this isn't working, suggests argument of sinc is not a number.
sinc covariance funciton
"""
X = sp.symbols('x_:' + str(input_dim))
Z = sp.symbols('z_:' + str(input_dim))
variance = sp.var('variance',positive=True)
if ARD:
lengthscales = [sp.var('lengthscale_%i' % i, positive=True) for i in range(input_dim)]
dist_string = ' + '.join(['(x_%i-z_%i)**2/lengthscale_%i**2' % (i, i, i) for i in range(input_dim)])
dist = parse_expr(dist_string)
f = variance*sinc(sp.pi*sp.sqrt(dist))
else:
lengthscale = sp.var('lengthscale',positive=True)
dist_string = ' + '.join(['(x_%i-z_%i)**2' % (i, i) for i in range(input_dim)])
dist = parse_expr(dist_string)
f = variance*sinc(sp.pi*sp.sqrt(dist)/lengthscale)
return kern(input_dim, [spkern(input_dim, f, name='sinc')])
def sympykern(input_dim, k=None, output_dim=1, name=None, param=None): def sympykern(input_dim, k=None, output_dim=1, name=None, param=None):
""" """
A base kernel object, where all the hard work in done by sympy. A base kernel object, where all the hard work in done by sympy.