Uplift Tree Visualization¶

Introduction¶

This example notebooks illustrates how to visualize uplift trees for interpretation and diagnosis.

Supported Models¶

These visualization functions work only for tree-based algorithms:

Uplift tree/random forests on KL divergence, Euclidean Distance, and Chi-Square
Uplift tree/random forests on Contextual Treatment Selection

Currently, they are NOT supporting Meta-learner algorithms

S-learner
T-learner
X-learner
R-learner

Supported Usage¶

This notebook will show how to use visualization for:

Uplift Tree and Uplift Random Forest
- Visualize a trained uplift classification tree model
- Visualize an uplift tree in a trained uplift random forests
Training and Validation Data
- Visualize the validation tree: fill the trained uplift classification tree with validation (or testing) data, and show the statistics for both training data and validation data
One Treatment Group and Multiple Treatment Groups
- Visualize the case where there are one control group and one treatment group
- Visualize the case where there are one control group and multiple treatment groups

Step 1 Load Modules¶

Load CausalML modules¶

from causalml.dataset import make_uplift_classification
from causalml.inference.tree import UpliftTreeClassifier, UpliftRandomForestClassifier
from causalml.inference.tree import uplift_tree_string, uplift_tree_plot

Load standard modules¶

import numpy as np
import pandas as pd
from IPython.display import Image
from sklearn.model_selection import train_test_split

One Control + One Treatment for Uplift Classification Tree¶

# Data generation
df, x_names = make_uplift_classification()

# Rename features for easy interpretation of visualization
x_names_new = ['feature_%s'%(i) for i in range(len(x_names))]
rename_dict = {x_names[i]:x_names_new[i] for i in range(len(x_names))}
df = df.rename(columns=rename_dict)
x_names = x_names_new

df.head()

df = df[df['treatment_group_key'].isin(['control','treatment1'])]

# Look at the conversion rate and sample size in each group
df.pivot_table(values='conversion',
               index='treatment_group_key',
               aggfunc=[np.mean, np.size],
               margins=True)

# Split data to training and testing samples for model validation (next section)
df_train, df_test = train_test_split(df, test_size=0.2, random_state=111)

# Train uplift tree
uplift_model = UpliftTreeClassifier(max_depth = 4, min_samples_leaf = 200, min_samples_treatment = 50, n_reg = 100, evaluationFunction='KL', control_name='control')

uplift_model.fit(df_train[x_names].values,
                 treatment=df_train['treatment_group_key'].values,
                 y=df_train['conversion'].values)

<causalml.inference.tree.models.UpliftTreeClassifier at 0x7f211a8704a8>

# Print uplift tree as a string
result = uplift_tree_string(uplift_model.fitted_uplift_tree, x_names)

feature_17 >= -1.3785915096595742?
yes -> feature_0 >= -0.6364361308885705?
		yes -> feature_6 >= -0.7090765407021462?
				yes -> {'treatment1': 0.603448, 'control': 0.470297}
				no  -> {'treatment1': 0.449612, 'control': 0.495798}
		no  -> {'treatment1': 0.46988, 'control': 0.52381}
no  -> {'treatment1': 0.388489, 'control': 0.559055}

Read the tree¶

First line: node split condition
impurity: the value for the loss function
total_sample: total sample size in this node
group_sample: sample size by treatment group
uplift score: the treatment effect between treatment and control (when there are multiple treatment groups, this is the maximum of the treatment effects)
uplift p_value: the p_value for the treatment effect
validation uplift score: when validation data is filled in the tree, this reflects the uplift score based on the - validation data. It can be compared with the uplift score (for training data) to check if there are over-fitting issue.

# Plot uplift tree
graph = uplift_tree_plot(uplift_model.fitted_uplift_tree,x_names)
Image(graph.create_png())

Visualize Validation Tree: One Control + One Treatment for Uplift Classification Tree¶

Note the validation uplift score will update.

### Fill the trained tree with testing data set 
# The uplift score based on testing dataset is shown as validation uplift score in the tree nodes
uplift_model.fill(X=df_test[x_names].values, treatment=df_test['treatment_group_key'].values, y=df_test['conversion'].values)

# Plot uplift tree
graph = uplift_tree_plot(uplift_model.fitted_uplift_tree,x_names)
Image(graph.create_png())

Visualize a Tree in Random Forest¶

# Split data to training and testing samples for model validation (next section)
df_train, df_test = train_test_split(df, test_size=0.2, random_state=111)

# Train uplift tree
uplift_model = UpliftRandomForestClassifier(n_estimators=5, max_depth = 5, min_samples_leaf = 200, min_samples_treatment = 50, n_reg = 100, evaluationFunction='KL', control_name='control')

uplift_model.fit(df_train[x_names].values,
                 treatment=df_train['treatment_group_key'].values,
                 y=df_train['conversion'].values)

# Specify a tree in the random forest (the index can be any integer from 0 to n_estimators-1)
uplift_tree = uplift_model.uplift_forest[0]
# Print uplift tree as a string
result = uplift_tree_string(uplift_tree.fitted_uplift_tree, x_names)

feature_17 >= -1.4802946520331732?
yes -> feature_15 >= 1.028652295155747?
		yes -> feature_4 >= 1.1517351173273966?
				yes -> {'treatment1': 0.646018, 'control': 0.25}
				no  -> {'treatment1': 0.525547, 'control': 0.411765}
		no  -> feature_16 >= -0.9531241143484912?
				yes -> {'treatment1': 0.513661, 'control': 0.397959}
				no  -> feature_14 >= -0.2021677782274923?
						yes -> {'treatment1': 0.417323, 'control': 0.611511}
						no  -> {'treatment1': 0.546154, 'control': 0.575342}
no  -> {'treatment1': 0.407767, 'control': 0.529412}

# Plot uplift tree
graph = uplift_tree_plot(uplift_tree.fitted_uplift_tree,x_names)
Image(graph.create_png())

Fill the tree with validation data¶

### Fill the trained tree with testing data set 
# The uplift score based on testing dataset is shown as validation uplift score in the tree nodes
uplift_tree.fill(X=df_test[x_names].values, treatment=df_test['treatment_group_key'].values, y=df_test['conversion'].values)

# Plot uplift tree
graph = uplift_tree_plot(uplift_tree.fitted_uplift_tree,x_names)
Image(graph.create_png())

One Control + Multiple Treatments¶

# Data generation
df, x_names = make_uplift_classification()
# Look at the conversion rate and sample size in each group
df.pivot_table(values='conversion',
               index='treatment_group_key',
               aggfunc=[np.mean, np.size],
               margins=True)

# Split data to training and testing samples for model validation (next section)
df_train, df_test = train_test_split(df, test_size=0.2, random_state=111)

# Train uplift tree
uplift_model = UpliftTreeClassifier(max_depth = 3, min_samples_leaf = 200, min_samples_treatment = 50, n_reg = 100, evaluationFunction='KL', control_name='control')

uplift_model.fit(df_train[x_names].values,
                 treatment=df_train['treatment_group_key'].values,
                 y=df_train['conversion'].values)

<causalml.inference.tree.models.UpliftTreeClassifier at 0x7f211a6b5f98>

# Plot uplift tree
# The uplift score represents the best uplift score among all treatment effects
graph = uplift_tree_plot(uplift_model.fitted_uplift_tree,x_names)
Image(graph.create_png())

Save the Plot¶

# Save the graph as pdf
graph.write_pdf("tbc.pdf")
# Save the graph as png
graph.write_png("tbc.png")

True

	mean	size
	conversion	conversion
treatment_group_key
control	0.511	1000
treatment1	0.514	1000
treatment2	0.559	1000
treatment3	0.600	1000
All	0.546	4000