def dcm_symm(countvec, alpha_symm, N=None, single=False):
"""Dirichlet-Compound Multinomial PMF (single path)"""
G = math.lgamma
K = len(countvec)
N = countvec.sum() if N is None else N
A = alpha_symm * K
assert single
log_numseq = 0
return log_numseq + \
-statutil.poch(A,N) + \
statutil.faster_lgamma_sum(countvec, alpha_symm) - K*G(alpha_symm)
def dcm_symm(countvec, alpha_symm, N=None, single=False):
"""Dirichlet-Compound Multinomial PMF (single path)"""
G = math.lgamma
K = len(countvec)
N = countvec.sum() if N is None else N
A = alpha_symm*K
assert single
log_numseq = 0
return log_numseq + \
-statutil.poch(A,N) + \
statutil.faster_lgamma_sum(countvec, alpha_symm) - K*G(alpha_symm)
def dcm(countvec, alpha, conc=None, N=None, single=False):
"""Dirichlet-Compound Multinomial PMF
Returns log-likelihood of counts, given dirchlet alpha vector
single=True ==> Return log-lik of just ONE sequence .. not really a DCM.
"""
G = math.lgamma
vG = sp.gammaln ## vectorized but slower
K = len(countvec); assert len(alpha)==K
N = countvec.sum() if N is None else N
A = alpha.sum() if conc is None else conc
log_numseq = 0 if single else G(N+1) - vG(countvec + 1).sum()
# G(A)-G(A+N) is nearly as fast as -pochhammer(A,N)... lame
return log_numseq + \
-statutil.poch(A,N) + \
vG(countvec+alpha).sum() - vG(alpha).sum()
def dcm(countvec, alpha, conc=None, N=None, single=False):
"""Dirichlet-Compound Multinomial PMF
Returns log-likelihood of counts, given dirchlet alpha vector
single=True ==> Return log-lik of just ONE sequence .. not really a DCM.
"""
G = math.lgamma
vG = sp.gammaln ## vectorized but slower
K = len(countvec)
assert len(alpha) == K
N = countvec.sum() if N is None else N
A = alpha.sum() if conc is None else conc
log_numseq = 0 if single else G(N + 1) - vG(countvec + 1).sum()
# G(A)-G(A+N) is nearly as fast as -pochhammer(A,N)... lame
return log_numseq + \
-statutil.poch(A,N) + \
vG(countvec+alpha).sum() - vG(alpha).sum()
def poch(N=700):
for i in range(N):
for j in range(N):
print "%d %d %.3f" % (i,j,statutil.poch(i,j))
def poch(N=700):
for i in range(N):
for j in range(N):
print "%d %d %.3f" % (i, j, statutil.poch(i, j))
