xgboost/demo/aft_survival/aft_survival_demo.py
Avinash Barnwal dcf439932a
Add Accelerated Failure Time loss for survival analysis task (#4763)
* [WIP] Add lower and upper bounds on the label for survival analysis

* Update test MetaInfo.SaveLoadBinary to account for extra two fields

* Don't clear qids_ for version 2 of MetaInfo

* Add SetInfo() and GetInfo() method for lower and upper bounds

* changes to aft

* Add parameter class for AFT; use enum's to represent distribution and event type

* Add AFT metric

* changes to neg grad to grad

* changes to binomial loss

* changes to overflow

* changes to eps

* changes to code refactoring

* changes to code refactoring

* changes to code refactoring

* Re-factor survival analysis

* Remove aft namespace

* Move function bodies out of AFTNormal and AFTLogistic, to reduce clutter

* Move function bodies out of AFTLoss, to reduce clutter

* Use smart pointer to store AFTDistribution and AFTLoss

* Rename AFTNoiseDistribution enum to AFTDistributionType for clarity

The enum class was not a distribution itself but a distribution type

* Add AFTDistribution::Create() method for convenience

* changes to extreme distribution

* changes to extreme distribution

* changes to extreme

* changes to extreme distribution

* changes to left censored

* deleted cout

* changes to x,mu and sd and code refactoring

* changes to print

* changes to hessian formula in censored and uncensored

* changes to variable names and pow

* changes to Logistic Pdf

* changes to parameter

* Expose lower and upper bound labels to R package

* Use example weights; normalize log likelihood metric

* changes to CHECK

* changes to logistic hessian to standard formula

* changes to logistic formula

* Comply with coding style guideline

* Revert back Rabit submodule

* Revert dmlc-core submodule

* Comply with coding style guideline (clang-tidy)

* Fix an error in AFTLoss::Gradient()

* Add missing files to amalgamation

* Address @RAMitchell's comment: minimize future change in MetaInfo interface

* Fix lint

* Fix compilation error on 32-bit target, when size_t == bst_uint

* Allocate sufficient memory to hold extra label info

* Use OpenMP to speed up

* Fix compilation on Windows

* Address reviewer's feedback

* Add unit tests for probability distributions

* Make Metric subclass of Configurable

* Address reviewer's feedback: Configure() AFT metric

* Add a dummy test for AFT metric configuration

* Complete AFT configuration test; remove debugging print

* Rename AFT parameters

* Clarify test comment

* Add a dummy test for AFT loss for uncensored case

* Fix a bug in AFT loss for uncensored labels

* Complete unit test for AFT loss metric

* Simplify unit tests for AFT metric

* Add unit test to verify aggregate output from AFT metric

* Use EXPECT_* instead of ASSERT_*, so that we run all unit tests

* Use aft_loss_param when serializing AFTObj

This is to be consistent with AFT metric

* Add unit tests for AFT Objective

* Fix OpenMP bug; clarify semantics for shared variables used in OpenMP loops

* Add comments

* Remove AFT prefix from probability distribution; put probability distribution in separate source file

* Add comments

* Define kPI and kEulerMascheroni in probability_distribution.h

* Add probability_distribution.cc to amalgamation

* Remove unnecessary diff

* Address reviewer's feedback: define variables where they're used

* Eliminate all INFs and NANs from AFT loss and gradient

* Add demo

* Add tutorial

* Fix lint

* Use 'survival:aft' to be consistent with 'survival:cox'

* Move sample data to demo/data

* Add visual demo with 1D toy data

* Add Python tests

Co-authored-by: Philip Cho <chohyu01@cs.washington.edu>
2020-03-25 13:52:51 -07:00

54 lines
2.1 KiB
Python

"""
Demo for survival analysis (regression) using Accelerated Failure Time (AFT) model
"""
from sklearn.model_selection import ShuffleSplit
import pandas as pd
import numpy as np
import xgboost as xgb
# The Veterans' Administration Lung Cancer Trial
# The Statistical Analysis of Failure Time Data by Kalbfleisch J. and Prentice R (1980)
df = pd.read_csv('../data/veterans_lung_cancer.csv')
print('Training data:')
print(df)
# Split features and labels
y_lower_bound = df['Survival_label_lower_bound']
y_upper_bound = df['Survival_label_upper_bound']
X = df.drop(['Survival_label_lower_bound', 'Survival_label_upper_bound'], axis=1)
# Split data into training and validation sets
rs = ShuffleSplit(n_splits=2, test_size=.7, random_state=0)
train_index, valid_index = next(rs.split(X))
dtrain = xgb.DMatrix(X.values[train_index, :])
dtrain.set_float_info('label_lower_bound', y_lower_bound[train_index])
dtrain.set_float_info('label_upper_bound', y_upper_bound[train_index])
dvalid = xgb.DMatrix(X.values[valid_index, :])
dvalid.set_float_info('label_lower_bound', y_lower_bound[valid_index])
dvalid.set_float_info('label_upper_bound', y_upper_bound[valid_index])
# Train gradient boosted trees using AFT loss and metric
params = {'verbosity': 0,
'objective': 'survival:aft',
'eval_metric': 'aft-nloglik',
'tree_method': 'hist',
'learning_rate': 0.05,
'aft_loss_distribution': 'normal',
'aft_loss_distribution_scale': 1.20,
'max_depth': 6,
'lambda': 0.01,
'alpha': 0.02}
bst = xgb.train(params, dtrain, num_boost_round=10000,
evals=[(dtrain, 'train'), (dvalid, 'valid')],
early_stopping_rounds=50)
# Run prediction on the validation set
df = pd.DataFrame({'Label (lower bound)': y_lower_bound[valid_index],
'Label (upper bound)': y_upper_bound[valid_index],
'Predicted label': bst.predict(dvalid)})
print(df)
# Show only data points with right-censored labels
print(df[np.isinf(df['Label (upper bound)'])])
# Save trained model
bst.save_model('aft_model.json')