Python Tensorflow概率错误:运算符NOTALLOWEDINGRAPHERROR:不允许在'tf.Tensor'上迭代
我试图通过提供一个似然函数,用NUTS来估计tensorflow中的一个模型。我已经检查过似然函数是否返回了合理的值。我将按照此处的设置设置螺母: 这里有一些设置优先级的示例,等等: 我的代码在这里的colab笔记本中: 我得到了错误:Python Tensorflow概率错误:运算符NOTALLOWEDINGRAPHERROR:不允许在'tf.Tensor'上迭代,python,tensorflow,tensorflow-probability,Python,Tensorflow,Tensorflow Probability,我试图通过提供一个似然函数,用NUTS来估计tensorflow中的一个模型。我已经检查过似然函数是否返回了合理的值。我将按照此处的设置设置螺母: 这里有一些设置优先级的示例,等等: 我的代码在这里的colab笔记本中: 我得到了错误:运算符或不允许的Ingraph错误:在tf上迭代。不允许使用张量:AutoGraph未转换此函数。尝试直接用@tf.function来装饰它。这是我第一次使用tensorflow,我对解释这个错误感到非常迷茫。如果我可以将起始参数值作为单个输入进行传递,这也
运算符或不允许的Ingraph错误:在
tf上迭代。不允许使用张量:AutoGraph未转换此函数。尝试直接用@tf.function来装饰它。
这是我第一次使用tensorflow,我对解释这个错误感到非常迷茫。如果我可以将起始参数值作为单个输入进行传递,这也将非常理想(我正在处理的示例没有这样做,但我假设这是可能的)
更新
看起来我必须改变@tf.function decorator的位置。采样器现在运行,但它为每个参数的所有样本提供相同的值。是否需要通过log_prob()函数传递联合分发?我显然错过了什么。我可以通过bfgs优化运行似然,并得到合理的结果(我在其他软件中通过固定参数的最大似然估计模型)。看起来我需要定义函数来返回联合分发并调用log_prob()。我可以这样做,如果我把它设置为逻辑回归(逻辑选择模型是逻辑分布的差异)。但是,我丢失了标准的封闭形式
我的职能如下:
@tf.function
def mmnl_log_prob(init_mu_b_time,init_sigma_b_time,init_a_car,init_a_train,init_b_cost,init_scale):
# Create priors for hyperparameters
mu_b_time = tfd.Sample(tfd.Normal(loc=init_mu_b_time, scale=init_scale),sample_shape=1).sample()
# HalfCauchy distributions are too wide for logit discrete choice
sigma_b_time = tfd.Sample(tfd.Normal(loc=init_sigma_b_time, scale=init_scale),sample_shape=1).sample()
# Create priors for parameters
a_car = tfd.Sample(tfd.Normal(loc=init_a_car, scale=init_scale),sample_shape=1).sample()
a_train = tfd.Sample(tfd.Normal(loc=init_a_train, scale=init_scale),sample_shape=1).sample()
# a_sm = tfd.Sample(tfd.Normal(loc=init_a_sm, scale=init_scale),sample_shape=1).sample()
b_cost = tfd.Sample(tfd.Normal(loc=init_b_cost, scale=init_scale),sample_shape=1).sample()
# Define a heterogeneous random parameter model with MultivariateNormalDiag()
# Use MultivariateNormalDiagPlusLowRank() to define nests, etc.
b_time = tfd.Sample(tfd.MultivariateNormalDiag( # b_time
loc=mu_b_time,
scale_diag=sigma_b_time),sample_shape=num_idx).sample()
# Definition of the utility functions
V1 = a_train + tfm.multiply(b_time,TRAIN_TT_SCALED) + b_cost * TRAIN_COST_SCALED
V2 = tfm.multiply(b_time,SM_TT_SCALED) + b_cost * SM_COST_SCALED
V3 = a_car + tfm.multiply(b_time,CAR_TT_SCALED) + b_cost * CAR_CO_SCALED
print("Vs",V1,V2,V3)
# Definition of loglikelihood
eV1 = tfm.multiply(tfm.exp(V1),TRAIN_AV_SP)
eV2 = tfm.multiply(tfm.exp(V2),SM_AV_SP)
eV3 = tfm.multiply(tfm.exp(V3),CAR_AV_SP)
eVD = eV1 + eV2 +
eV3
print("eVs",eV1,eV2,eV3,eVD)
l1 = tfm.multiply(tfm.truediv(eV1,eVD),tf.cast(tfm.equal(CHOICE,1),tf.float32))
l2 = tfm.multiply(tfm.truediv(eV2,eVD),tf.cast(tfm.equal(CHOICE,2),tf.float32))
l3 = tfm.multiply(tfm.truediv(eV3,eVD),tf.cast(tfm.equal(CHOICE,3),tf.float32))
ll = tfm.reduce_sum(tfm.log(l1+l2+l3))
print("ll",ll)
return ll
nuts_samples = 1000
nuts_burnin = 500
chains = 4
## Initial step size
init_step_size=.3
init = [0.,0.,0.,0.,0.,.5]
##
## NUTS (using inner step size averaging step)
##
@tf.function
def nuts_sampler(init):
nuts_kernel = tfp.mcmc.NoUTurnSampler(
target_log_prob_fn=mmnl_log_prob,
step_size=init_step_size,
)
adapt_nuts_kernel = tfp.mcmc.DualAveragingStepSizeAdaptation(
inner_kernel=nuts_kernel,
num_adaptation_steps=nuts_burnin,
step_size_getter_fn=lambda pkr: pkr.step_size,
log_accept_prob_getter_fn=lambda pkr: pkr.log_accept_ratio,
step_size_setter_fn=lambda pkr, new_step_size: pkr._replace(step_size=new_step_size)
)
samples_nuts_, stats_nuts_ = tfp.mcmc.sample_chain(
num_results=nuts_samples,
current_state=init,
kernel=adapt_nuts_kernel,
num_burnin_steps=100,
parallel_iterations=5)
return samples_nuts_, stats_nuts_
samples_nuts, stats_nuts = nuts_sampler(init)
函数的调用如下所示:
@tf.function
def mmnl_log_prob(init_mu_b_time,init_sigma_b_time,init_a_car,init_a_train,init_b_cost,init_scale):
# Create priors for hyperparameters
mu_b_time = tfd.Sample(tfd.Normal(loc=init_mu_b_time, scale=init_scale),sample_shape=1).sample()
# HalfCauchy distributions are too wide for logit discrete choice
sigma_b_time = tfd.Sample(tfd.Normal(loc=init_sigma_b_time, scale=init_scale),sample_shape=1).sample()
# Create priors for parameters
a_car = tfd.Sample(tfd.Normal(loc=init_a_car, scale=init_scale),sample_shape=1).sample()
a_train = tfd.Sample(tfd.Normal(loc=init_a_train, scale=init_scale),sample_shape=1).sample()
# a_sm = tfd.Sample(tfd.Normal(loc=init_a_sm, scale=init_scale),sample_shape=1).sample()
b_cost = tfd.Sample(tfd.Normal(loc=init_b_cost, scale=init_scale),sample_shape=1).sample()
# Define a heterogeneous random parameter model with MultivariateNormalDiag()
# Use MultivariateNormalDiagPlusLowRank() to define nests, etc.
b_time = tfd.Sample(tfd.MultivariateNormalDiag( # b_time
loc=mu_b_time,
scale_diag=sigma_b_time),sample_shape=num_idx).sample()
# Definition of the utility functions
V1 = a_train + tfm.multiply(b_time,TRAIN_TT_SCALED) + b_cost * TRAIN_COST_SCALED
V2 = tfm.multiply(b_time,SM_TT_SCALED) + b_cost * SM_COST_SCALED
V3 = a_car + tfm.multiply(b_time,CAR_TT_SCALED) + b_cost * CAR_CO_SCALED
print("Vs",V1,V2,V3)
# Definition of loglikelihood
eV1 = tfm.multiply(tfm.exp(V1),TRAIN_AV_SP)
eV2 = tfm.multiply(tfm.exp(V2),SM_AV_SP)
eV3 = tfm.multiply(tfm.exp(V3),CAR_AV_SP)
eVD = eV1 + eV2 +
eV3
print("eVs",eV1,eV2,eV3,eVD)
l1 = tfm.multiply(tfm.truediv(eV1,eVD),tf.cast(tfm.equal(CHOICE,1),tf.float32))
l2 = tfm.multiply(tfm.truediv(eV2,eVD),tf.cast(tfm.equal(CHOICE,2),tf.float32))
l3 = tfm.multiply(tfm.truediv(eV3,eVD),tf.cast(tfm.equal(CHOICE,3),tf.float32))
ll = tfm.reduce_sum(tfm.log(l1+l2+l3))
print("ll",ll)
return ll
nuts_samples = 1000
nuts_burnin = 500
chains = 4
## Initial step size
init_step_size=.3
init = [0.,0.,0.,0.,0.,.5]
##
## NUTS (using inner step size averaging step)
##
@tf.function
def nuts_sampler(init):
nuts_kernel = tfp.mcmc.NoUTurnSampler(
target_log_prob_fn=mmnl_log_prob,
step_size=init_step_size,
)
adapt_nuts_kernel = tfp.mcmc.DualAveragingStepSizeAdaptation(
inner_kernel=nuts_kernel,
num_adaptation_steps=nuts_burnin,
step_size_getter_fn=lambda pkr: pkr.step_size,
log_accept_prob_getter_fn=lambda pkr: pkr.log_accept_ratio,
step_size_setter_fn=lambda pkr, new_step_size: pkr._replace(step_size=new_step_size)
)
samples_nuts_, stats_nuts_ = tfp.mcmc.sample_chain(
num_results=nuts_samples,
current_state=init,
kernel=adapt_nuts_kernel,
num_burnin_steps=100,
parallel_iterations=5)
return samples_nuts_, stats_nuts_
samples_nuts, stats_nuts = nuts_sampler(init)
我的问题有答案了!这只是一个不同命名法的问题。我需要将我的模型定义为一个softmax函数,我知道这就是我所说的“logit模型”,但它并没有为我点击。下面的博文让我顿悟:
我的问题有答案了!这只是一个不同命名法的问题。我需要将我的模型定义为一个softmax函数,我知道这就是我所说的“logit模型”,但它并没有为我点击。下面的博文让我顿悟: 此处交叉张贴:此处交叉张贴:查看我的更新问题:查看我的更新问题: