Example of use of Latent Class MNL
# Install necessary requirements
# If you run this notebook on Google Colab, or in standalone mode, you need to install the required packages.
# Uncomment the following lines:
# !pip install choice-learn
# If you run the notebook within the GitHub repository, you need to run the following lines, that can skipped otherwise:
import os
import sys
sys.path.append("../../")
import os
os.environ["CUDA_VISIBLE_DEVICES"] = ""
import matplotlib as mpl
import numpy as np
import pandas as pd
import tensorflow as tf
Let's use the Electricity Dataset used in this tutorial.
from choice_learn.models.simple_mnl import SimpleMNL
from choice_learn.models.latent_class_mnl import LatentClassSimpleMNL
lc_model = LatentClassSimpleMNL(n_latent_classes=3, fit_method="mle", optimizer="lbfgs", epochs=1000, lbfgs_tolerance=1e-20)
hist, results = lc_model.fit(elec_dataset, verbose=1)
print("Latent Class Model weights:")
print("Classes Logits:", lc_model.latent_logits)
for i in range(3):
print("\n")
print(f"Model Nb {i}, weights:", lc_model.models[i].weights)
nll = (lc_model.evaluate(elec_dataset) * len(elec_dataset)).numpy()
print(f"Negative Log-Likelihood: {nll}")
report = lc_model.compute_report(elec_dataset)
def format_color_groups(df):
cmap = mpl.cm.get_cmap("Set1")
colors = [mpl.colors.rgb2hex(cmap(i)) for i in range(cmap.N)]
x = df.copy()
factors = list(x['Latent Class'].unique())
i = 0
for factor in factors:
style = f'background-color: {colors[i]}'
x.loc[x['Latent Class'] == factor, :] = style
i += 1
return x
report.style.apply(format_color_groups, axis=None)
Using L-BFGS optimizer, setting up .fit() function
Using L-BFGS optimizer, setting up .fit() function
Using L-BFGS optimizer, setting up .fit() function
/var/folders/zz/r1py7zhj35q75v09h8_42nzh0000gp/T/ipykernel_67121/1263996749.py:4: MatplotlibDeprecationWarning: The get_cmap function was deprecated in Matplotlib 3.7 and will be removed two minor releases later. Use ``matplotlib.colormaps[name]`` or ``matplotlib.colormaps.get_cmap(obj)`` instead.
cmap = mpl.cm.get_cmap("Set1")
| Latent Class | Coefficient Name | Coefficient Estimation | Std. Err | z_value | P(.>z) | |
|---|---|---|---|---|---|---|
| 0 | 0 | Weights_items_features_0 | -0.675645 | 0.023987 | -28.167109 | 0.000000 |
| 1 | 0 | Weights_items_features_1 | -0.060604 | 0.008162 | -7.424849 | 0.000000 |
| 2 | 0 | Weights_items_features_2 | 1.851951 | 0.054914 | 33.724579 | 0.000000 |
| 3 | 0 | Weights_items_features_3 | 1.322549 | 0.048159 | 27.462420 | 0.000000 |
| 4 | 0 | Weights_items_features_4 | -5.857089 | 0.191162 | -30.639460 | 0.000000 |
| 5 | 0 | Weights_items_features_5 | -6.513206 | 0.195680 | -33.285046 | 0.000000 |
| 6 | 1 | Weights_items_features_0 | -1.817566 | 0.077771 | -23.370796 | 0.000000 |
| 7 | 1 | Weights_items_features_1 | -1.726365 | 0.058838 | -29.340986 | 0.000000 |
| 8 | 1 | Weights_items_features_2 | 3.696567 | 0.160258 | 23.066404 | 0.000000 |
| 9 | 1 | Weights_items_features_3 | 4.111840 | 0.157179 | 26.160225 | 0.000000 |
| 10 | 1 | Weights_items_features_4 | -26.693516 | 3.274723 | -8.151381 | 0.000000 |
| 11 | 1 | Weights_items_features_5 | -14.925840 | 0.634699 | -23.516403 | 0.000000 |
| 12 | 2 | Weights_items_features_0 | -2.104791 | 0.104296 | -20.181009 | 0.000000 |
| 13 | 2 | Weights_items_features_1 | -1.652622 | 0.073820 | -22.387188 | 0.000000 |
| 14 | 2 | Weights_items_features_2 | -5.554287 | 0.245318 | -22.641151 | 0.000000 |
| 15 | 2 | Weights_items_features_3 | -13.565555 | 0.544168 | -24.928965 | 0.000000 |
| 16 | 2 | Weights_items_features_4 | -9.794930 | 0.631004 | -15.522781 | 0.000000 |
| 17 | 2 | Weights_items_features_5 | -12.126673 | 0.681118 | -17.804060 | 0.000000 |
Latent Conditional Logit
We used a very simple MNL. Here we simulate the same MNL, by using the Conditional-Logit formulation.\ Don't hesitate to read the conditional-MNL tutorial to better understand how to use this formulation.
lc_model_2 = LatentClassConditionalLogit(n_latent_classes=3,
fit_method="mle",
optimizer="lbfgs",
epochs=1000,
lbfgs_tolerance=1e-12)
For each feature, let's add a coefficient that is shared by all items:
lc_model_2.add_shared_coefficient(coefficient_name="pf",
feature_name="pf",
items_indexes=[0, 1, 2, 3])
lc_model_2.add_shared_coefficient(coefficient_name="cl",
feature_name="cl",
items_indexes=[0, 1, 2, 3])
lc_model_2.add_shared_coefficient(coefficient_name="loc",
feature_name="loc",
items_indexes=[0, 1, 2, 3])
lc_model_2.add_shared_coefficient(coefficient_name="wk",
feature_name="wk",
items_indexes=[0, 1, 2, 3])
lc_model_2.add_shared_coefficient(coefficient_name="tod",
feature_name="tod",
items_indexes=[0, 1, 2, 3])
lc_model_2.add_shared_coefficient(coefficient_name="seas",
feature_name="seas",
items_indexes=[0, 1, 2, 3])
print("Latent Class Model weights:")
print("Classes Logits:", lc_model_2.latent_logits)
for i in range(3):
print("\n")
print(f"Model Nb {i}, weights:", lc_model_2.models[i].trainable_weights)
Just like any ChoiceModel you can get the probabilities:
If you want to use more complex formulations of Latent Class models, you can directly use the BaseLatentClassModel from choice_learn.models.base_model:
manual_lc = BaseLatentClassModel(
model_class=SimpleMNL,
model_parameters={"add_exit_choice": False},
n_latent_classes=3,
fit_method="mle",
epochs=1000,
optimizer="lbfgs",
lbfgs_tolerance=1e-12
)
manual_lc.instantiate(n_items=4,
n_shared_features=0,
n_items_features=6)
manual_hist = manual_lc.fit(elec_dataset, verbose=1)
If you need to go deeper, you can look here to see different implementations that could help you.