def mnl_simulate(data, coeff, numalts, GPU=False, returnprobs=False):
logger.debug(
'start: MNL simulation with len(data)={} and numalts={}'.format(
len(data), numalts))
atype = 'numpy' if not GPU else 'cuda'
data = np.transpose(data)
coeff = np.reshape(np.array(coeff), (1, len(coeff)))
data, coeff = PMAT(data, atype), PMAT(coeff, atype)
probs = mnl_probs(data, coeff, numalts)
if returnprobs:
return np.transpose(probs.get_mat())
# convert to cpu from here on - gpu doesn't currently support these ops
if probs.typ == 'cuda':
probs = PMAT(probs.get_mat())
probs = probs.cumsum(axis=0)
r = pmat.random(probs.size() / numalts)
choices = probs.subtract(r, inplace=True).firstpositive(axis=0)
logger.debug('finish: MNL simulation')
return choices.get_mat()
def mnl_simulate(data, coeff, numalts, GPU=False, returnprobs=False):
logger.debug(
'start: MNL simulation with len(data)={} and numalts={}'.format(
len(data), numalts))
atype = 'numpy' if not GPU else 'cuda'
data = np.transpose(data)
coeff = np.reshape(np.array(coeff), (1, len(coeff)))
data, coeff = PMAT(data, atype), PMAT(coeff, atype)
probs = mnl_probs(data, coeff, numalts)
if returnprobs:
return np.transpose(probs.get_mat())
# convert to cpu from here on - gpu doesn't currently support these ops
if probs.typ == 'cuda':
probs = PMAT(probs.get_mat())
probs = probs.cumsum(axis=0)
r = pmat.random(probs.size() / numalts)
choices = probs.subtract(r, inplace=True).firstpositive(axis=0)
logger.debug('finish: MNL simulation')
return choices.get_mat()
def mnl_simulate(data, coeff, numalts, GPU=False, returnprobs=True):
"""
Get the probabilities for each chooser choosing between `numalts`
alternatives.
Parameters
----------
data : 2D array
The data are expected to be in "long" form where each row is for
one alternative. Alternatives are in groups of `numalts` rows per
choosers. Alternatives must be in the same order for each chooser.
coeff : 1D array
The model coefficients corresponding to each column in `data`.
numalts : int
The number of alternatives available to each chooser.
GPU : bool, optional
returnprobs : bool, optional
If True, return the probabilities for each chooser/alternative instead
of actual choices.
Returns
-------
probs or choices: 2D array
If `returnprobs` is True the probabilities are a 2D array with a
row for each chooser and columns for each alternative.
"""
logger.debug(
'start: MNL simulation with len(data)={} and numalts={}'.format(
len(data), numalts))
atype = 'numpy' if not GPU else 'cuda'
data = np.transpose(data)
coeff = np.reshape(np.array(coeff), (1, len(coeff)))
data, coeff = PMAT(data, atype), PMAT(coeff, atype)
probs = mnl_probs(data, coeff, numalts)
if returnprobs:
return np.transpose(probs.get_mat())
# convert to cpu from here on - gpu doesn't currently support these ops
if probs.typ == 'cuda':
probs = PMAT(probs.get_mat())
probs = probs.cumsum(axis=0)
r = pmat.random(probs.size() / numalts)
choices = probs.subtract(r, inplace=True).firstpositive(axis=0)
logger.debug('finish: MNL simulation')
return choices.get_mat()
def mnl_simulate(data, coeff, numalts, GPU=False, returnprobs=True):
"""
Get the probabilities for each chooser choosing between `numalts`
alternatives.
Parameters
----------
data : 2D array
The data are expected to be in "long" form where each row is for
one alternative. Alternatives are in groups of `numalts` rows per
choosers. Alternatives must be in the same order for each chooser.
coeff : 1D array
The model coefficients corresponding to each column in `data`.
numalts : int
The number of alternatives available to each chooser.
GPU : bool, optional
returnprobs : bool, optional
If True, return the probabilities for each chooser/alternative instead
of actual choices.
Returns
-------
probs or choices: 2D array
If `returnprobs` is True the probabilities are a 2D array with a
row for each chooser and columns for each alternative.
"""
logger.debug(
'start: MNL simulation with len(data)={} and numalts={}'.format(
len(data), numalts))
atype = 'numpy' if not GPU else 'cuda'
data = np.transpose(data)
coeff = np.reshape(np.array(coeff), (1, len(coeff)))
data, coeff = PMAT(data, atype), PMAT(coeff, atype)
probs = mnl_probs(data, coeff, numalts)
if returnprobs:
return np.transpose(probs.get_mat())
# convert to cpu from here on - gpu doesn't currently support these ops
if probs.typ == 'cuda':
probs = PMAT(probs.get_mat())
probs = probs.cumsum(axis=0)
r = pmat.random(probs.size() / numalts)
choices = probs.subtract(r, inplace=True).firstpositive(axis=0)
logger.debug('finish: MNL simulation')
return choices.get_mat()
def mnl_loglik(beta,data,chosen,numalts,weights=None,lcgrad=False,stderr=0):
numvars = beta.size
numobs = data.size()/numvars/numalts
beta = np.reshape(beta,(1,beta.size))
beta = PMAT(beta,data.typ)
probs = mnl_probs(data,beta,numalts)
if lcgrad:
assert weights
gradmat = weights.subtract(probs).reshape(1,probs.size())
else:
gradmat = chosen.subtract(probs).reshape(1,probs.size())
gradmat = data.multiply_by_row(gradmat)
# this line is a bit hackish - you can't do the whole sum at once on a gpu
# need to shorten the length of the axis over which to sum
gradarr = gradmat.reshape(numvars*numalts,numobs)
if weights is not None and not lcgrad: gradarr = gradarr.element_multiply(weights,inplace=True)
gradarr = gradarr.sum(axis=1).reshape(numvars,numalts).sum(axis=1)
gradmat.reshape(numvars,numalts*numobs)
if stderr:
if not lcgrad: return get_standard_error(get_hessian(gradmat.get_mat()))
else: return np.zeros(beta.size())
chosen.reshape(numalts,numobs)
if weights is not None:
loglik = (probs.log(inplace=True).element_multiply(weights,inplace=True) \
.element_multiply(chosen,inplace=True)).sum(axis=1).sum(axis=0)
else:
loglik = (probs.log(inplace=True).element_multiply(chosen,inplace=True)).sum(axis=1).sum(axis=0)
if loglik.typ == 'numpy':
loglik, gradarr = loglik.get_mat(), gradarr.get_mat()
else:
loglik = loglik.get_mat()[0,0]
gradarr = np.reshape(gradarr.get_mat(),(1,gradarr.size()))[0]
return -1*loglik, -1*gradarr
def mnl_simulate(data, coeff, numalts, GPU=0, returnprobs=0):
atype = 'numpy' if not GPU else 'cuda'
data = np.transpose(data)
coeff = np.reshape(np.array(coeff),(1,len(coeff)))
data, coeff = PMAT(data,atype), PMAT(coeff,atype)
probs = mnl_probs(data,coeff,numalts)
if returnprobs: return np.transpose(probs.get_mat())
# convert to cpu from here on - gpu doesn't currently support these ops
if probs.typ == 'cuda': probs = PMAT(probs.get_mat())
probs = probs.cumsum(axis=0)
r = pmat.random(probs.size()/numalts)
choices = probs.subtract(r,inplace=True).firstpositive(axis=0)
return choices.get_mat()
def mnl_simulate(data, coeff, numalts, GPU=0, returnprobs=0):
atype = 'numpy' if not GPU else 'cuda'
data = np.transpose(data)
coeff = np.reshape(np.array(coeff), (1, len(coeff)))
data, coeff = PMAT(data, atype), PMAT(coeff, atype)
probs = mnl_probs(data, coeff, numalts)
if returnprobs: return np.transpose(probs.get_mat())
# convert to cpu from here on - gpu doesn't currently support these ops
if probs.typ == 'cuda': probs = PMAT(probs.get_mat())
probs = probs.cumsum(axis=0)
r = pmat.random(probs.size() / numalts)
choices = probs.subtract(r, inplace=True).firstpositive(axis=0)
return choices.get_mat()
