I am learning the pymc package from the book "Bayesian Methods for Hackers: Probabilistic Programming and Bayesian Inference". While executing some codes shown in the picture, I got errors. Does anybody know where is the problem? Is it because of the package installation or version?

For installation of pymc package, I followed the instruction of https://www.pymc.io/projects/docs/en/stable/installation.html

The python code:

import pymc as pm

with pm.Model() as model:

lambda_1 = pm.Exponential("lambda_1", 1)

lambda_2 = pm.Exponential("lambda_2", 1)

tau = pm.DiscreteUniform("tau", lower=0, upper=10)

lambda_1.value

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AttributeError Traceback (most recent call last)

Cell In[4], line 6

3 lambda_2 = pm.Exponential("lambda_2", 1)

4 tau = pm.DiscreteUniform("tau", lower=0, upper=10)

----> 6 lambda_1.value

AttributeError: 'TensorVariable' object has no attribute 'value'

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@pm.Deterministic

def lambda_(tau=tau, lambda_1=lambda_1, lambda_2=lambda_2):

out = np.zeros(n_data_points)

out[:tau] = lambda_1 # lambda before tau is lambda 1

out[tau:] = lambda_2 # lambda after tau is lambda 2

return out

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TypeError Traceback (most recent call last)

Cell In[5], line 1

----> 1 @pm.Deterministic

2 def lambda_(tau=tau, lambda_1=lambda_1, lambda_2=lambda_2):

3 out = np.zeros(n_data_points)

4 out[:tau] = lambda_1 # lambda before tau is lambda 1

TypeError: Deterministic() missing 1 required positional argument: 'var'