ezr 0.9.2

Explainable multi-objective optimization

EZR(1) - Explainable Multi-Objective Optimization

NAME

ezr — explainable multi-objective optimization via decision trees, clustering, Naive Bayes, and active learning

SYNOPSIS

ezr [OPTIONS] COMMAND [FILE]
python ezeg.py [OPTIONS] COMMAND [FILE]
pytest ezeg.py [-v] [-k PATTERN]

DESCRIPTION

ezr is a lightweight toolkit for multi-objective optimization and explainable AI. It summarizes CSV data into Num/Sym columns, builds decision trees that minimize distance to ideal outcomes, clusters rows via k-means or recursive halving, and supports active learning with Naive Bayes or centroid-based acquisition.

ezr is an experiment in "how low can you go?". i.e. how little data do you need for effective AI. THe code using active learning to label a small number of (say) 50 informative examples. These are used to build a regression tree which, in turn, is used to sort the unlabelled test data. Repeated studies show that by labelling the first (say) 5 examples, then the selected row optimzies as well or better than the conclusions mae by state of the art optimizers SMAC (which runs two orders of magnitice slower than ezr).

Input is CSV. The header row defines column roles:

[A-Z]*    Numeric (e.g. "Age")
[a-z]*    Symbolic (e.g. "job")
[A-Z]*+   Maximize goal (e.g. "Pay+")
[A-Z]*-   Minimize goal (e.g. "Cost-")
[a-z]*!   Class label (e.g. "sick!")
*X        Ignored (e.g. "idX")
?         Missing value (in data rows, not header)

The codebase is two files:

• ezr.py — the library (columns, data, distance, trees, clustering, Bayes, active learning, stats)
• ezeg.py — the CLI driver and all test/demo functions

INSTALLATION

Option A: Install as a package

git clone http://github.com/timm/ezr
cd ezr
pip install -e .

This creates the global ezr command. Edits to ezr.py and ezeg.py take effect immediately.

ezr --h
ezr --see auto93.csv
ezr --seed=42 --test auto93.csv

To uninstall:

pip uninstall ezr

Option B: Run from the directory

git clone http://github.com/timm/ezr
cd ezr
python ezeg.py --h
python ezeg.py --see auto93.csv

No installation required. Just needs Python 3.12+.

Sample data

mkdir -p $HOME/gits
git clone http://github.com/timm/moot $HOME/gits/moot

COMMANDS

--h                 Show help text
--list              List all available demos and tests
--egs FILE          Run all demos sequentially on FILE
--see FILE          Show grown decision tree (Rung 1: association)
--funny FILE        Test rows against tree leaves, flag anomalies (Rung 2)
--plan FILE         Generate counterfactual plans (Rung 3: what-if)
--test FILE         Run full train/predict/score pipeline
--classify FILE     Run incremental Naive Bayes classification
--cluster FILE      Run clustering benchmark table
--acquire FILE      Compare active learning strategies

OPTIONS

Options update the global configuration. Use --key=value syntax.

Learning & Trees

--learn.leaf=3      Minimum examples per leaf
--learn.budget=50   Number of rows to evaluate
--learn.check=5     Number of guesses to check
--learn.start=4     Initial number of labels

Distance & Bayes

--p=2               Distance metric (1=Manhattan, 2=Euclidean)
--bayes.m=2         m-estimate for Naive Bayes
--bayes.k=1         k-estimate (Laplace smoothing)
--few=512           Max unlabelled rows in active learning

Statistics

--stats.cliffs=0.195  Cliff's Delta threshold
--stats.conf=1.36     KS test confidence coefficient
--stats.eps=0.35      Margin of error multiplier

Display

--seed=1            Random number seed
--show.show=30      Tree display width
--show.decimals=2   Decimal places for floats

Options and commands can be interleaved. Options apply to all subsequent commands:

ezr --seed=42 --learn.budget=30 --test auto93.csv --see auto93.csv

TESTING

Run all tests with pytest

pip install pytest
pytest ezeg.py -v

Run a single test

pytest ezeg.py -k test_num

Run all demos via the CLI

ezr --egs auto93.csv

Available test functions

test_o          String formatting
test_table      Tabular output
test_thing      Type coercion
test_nest       Nested namespace setting
test_csv        CSV reading
test_h          Help text
test_the        Config parsing
test_list       List all demos
test_egs        Run all demos
test_num        Num column statistics
test_sym        Sym column entropy
test_pick       Random sampling from distributions
test_cols       Column extraction logic
test_data       Data object population
test_addsub     Incremental add/subtract rows
test_classify   Naive Bayes classification
test_distx      Independent variable distance
test_disty      Dependent variable distance
test_tree       Decision tree (Rung 1)
test_funny      Anomaly detection (Rung 2)
test_plan       Counterfactual plans (Rung 3)
test_test       Train/predict/score pipeline
test_cluster    Clustering benchmarks
test_acquire    Active learning comparison

LIBRARY USAGE

ezr.py exports everything needed to use the toolkit programmatically:

from ezr import *

d = Data(csv("auto93.csv"))
win = wins(d)
t = treeGrow(d, d.rows)
treeShow(t)

for r in sorted(d.rows, key=lambda r: disty(d, r))[:5]:
    print(win(r), r)

This generates the following where D is distance to heaven (lower values are better), n is the number of examples in that branch, and goals shows the rows in that branch.

$ ezr --tree ~/gits/moot/optimize/misc/auto93.csv
                               D       N     Goals
                               ====  =====   =====
                              ,0.66 ,( 50), {Acc+=15.51, Lbs-=2888.64, Mpg+=24.60}
Clndrs <= 5                   ,0.61 ,( 26), {Acc+=16.43, Lbs-=2204.46, Mpg+=30.38}
|   Volume <= 98              ,0.59 ,( 14), {Acc+=17.15, Lbs-=2024.64, Mpg+=33.57}
|   |   Volume <= 91          ,0.59 ,(  9), {Acc+=17.09, Lbs-=1927.67, Mpg+=35.56}
|   |   |   origin != 3       ,0.58 ,(  4), {Acc+=17.35, Lbs-=1908.00, Mpg+=37.50}
|   |   |   origin == 3       ,0.59 ,(  5), {Acc+=16.88, Lbs-=1943.40, Mpg+=34.00}
|   |   Volume > 91           ,0.60 ,(  5), {Acc+=17.26, Lbs-=2199.20, Mpg+=30.00}
|   Volume > 98               ,0.64 ,( 12), {Acc+=15.58, Lbs-=2414.25, Mpg+=26.67}
|   |   origin != 2           ,0.61 ,(  5), {Acc+=15.64, Lbs-=2344.00, Mpg+=30.00}
|   |   origin == 2           ,0.66 ,(  7), {Acc+=15.54, Lbs-=2464.43, Mpg+=24.29}
Clndrs > 5                    ,0.72 ,( 24), {Acc+=14.52, Lbs-=3629.83, Mpg+=18.33}
|   origin != 1               ,0.63 ,(  3), {Acc+=14.93, Lbs-=3000.00, Mpg+=26.67}
|   origin == 1               ,0.73 ,( 21), {Acc+=14.46, Lbs-=3719.81, Mpg+=17.14}
|   |   Volume <= 302         ,0.71 ,( 12), {Acc+=15.88, Lbs-=3385.92, Mpg+=19.17}
|   |   |   Clndrs <= 6       ,0.71 ,(  8), {Acc+=16.94, Lbs-=3308.25, Mpg+=20.00}
|   |   |   |   Model <= 75   ,0.71 ,(  5), {Acc+=16.20, Lbs-=3219.40, Mpg+=20.00}
|   |   |   |   Model > 75    ,0.71 ,(  3), {Acc+=18.17, Lbs-=3456.33, Mpg+=20.00}
|   |   |   Clndrs > 6        ,0.73 ,(  4), {Acc+=13.77, Lbs-=3541.25, Mpg+=17.50}
|   |   Volume > 302          ,0.75 ,(  9), {Acc+=12.57, Lbs-=4165.00, Mpg+=14.44}
|   |   |   Model > 73        ,0.71 ,(  3), {Acc+=13.37, Lbs-=4171.33, Mpg+=20.00}
|   |   |   Model <= 73       ,0.76 ,(  6), {Acc+=12.17, Lbs-=4161.83, Mpg+=11.67}

Key exports: Data, Num, Sym, Cols, Tree, adds, clone, mid, spread, norm, disty, distx, treeGrow, treeLeaf, treeShow, treePlan, kmeans, kpp, rhalf, half, like, likes, classify, acquire, wins, ready, csv, o, table, the.

FILES

ezr.py          Library (columns, data, trees, clustering, Bayes, stats)
ezeg.py         CLI driver, demos, and test functions
pyproject.toml  Package configuration

AUTHOR

Tim Menzies [e-mail], 2026. MIT License.

SEE ALSO

• Repository: http://github.com/timm/ezr
• Sample data: http://github.com/timm/moot