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https://github.com/jeremiegince/automlpy

This package is an automatic machine learning module whose function is to optimize the hyper-parameters of an automatic learning model.
https://github.com/jeremiegince/automlpy

automl deep-learning gaussian-processes grid-search-hyperparameters machine-learning multiprocessing python3 pytorch random-search sklearn tensorflow

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This package is an automatic machine learning module whose function is to optimize the hyper-parameters of an automatic learning model.

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README

        

---------------------------------------------------------------------------

This package is an automatic machine learning module whose function is to optimize the hyper-parameters
of an automatic learning model.

In this package you can find: a grid search method, a random search algorithm and a Gaussian process search method.
Everything is implemented to be compatible with the _Tensorflow_, _pyTorch_ and _sklearn_ libraries.

# Installation

## Latest stable version:
```
pip install AutoMLpy
```

## Latest unstable version:
0. Download the .whl file [here](https://github.com/JeremieGince/AutoMLpy/blob/main/dist/AutoMLpy-0.0.3-py3-none-any.whl);
1. Copy the path of this file on your computer;
2. pip install it with ``` pip install [path].whl ```

## With pip+git:
```
pip install git+https://github.com/JeremieGince/AutoMLpy
```

---------------------------------------------------------------------------
# Example - MNIST optimization with Tensorflow & Keras

Here you can see an example on how to optimize a model made with Tensorflow and Keras on the popular dataset MNIST.

## Imports

We start by importing some useful stuff.

```python
# Some useful packages
from typing import Union, Tuple
import time
import numpy as np
import pandas as pd
import pprint

# Tensorflow
import tensorflow as tf
import tensorflow_datasets as tfds

# Importing the HPOptimizer and the RandomHpSearch from the AutoMLpy package.
from AutoMLpy import HpOptimizer, RandomHpSearch

```

## Dataset

Now we load the MNIST dataset in the tensorflow way.

```python
def normalize_img(image, label):
"""Normalizes images: `uint8` -> `float32`."""
return tf.cast(image, tf.float32) / 255., label

def get_tf_mnist_dataset(**kwargs):
# https://www.tensorflow.org/datasets/keras_example
(ds_train, ds_test), ds_info = tfds.load(
'mnist',
split=['train', 'test'],
shuffle_files=True,
as_supervised=True,
with_info=True,
)

# Build training pipeline
ds_train = ds_train.map(normalize_img, num_parallel_calls=tf.data.experimental.AUTOTUNE)
ds_train = ds_train.cache()
ds_train = ds_train.shuffle(ds_info.splits['train'].num_examples)
ds_train = ds_train.batch(128)
ds_train = ds_train.prefetch(tf.data.experimental.AUTOTUNE)

# Build evaluation pipeline
ds_test = ds_test.map(normalize_img, num_parallel_calls=tf.data.experimental.AUTOTUNE)
ds_test = ds_test.batch(128)
ds_test = ds_test.cache()
ds_test = ds_test.prefetch(tf.data.experimental.AUTOTUNE)

return ds_train, ds_test
```

## Keras Model

Now we make a function that return a keras model given a set of hyper-parameters (hp).

```python
def get_tf_mnist_model(**hp):

if hp.get("use_conv", False):
model = tf.keras.models.Sequential([
# Convolution layers
tf.keras.layers.Conv2D(10, 3, padding="same", input_shape=(28, 28, 1)),
tf.keras.layers.MaxPool2D((2, 2)),
tf.keras.layers.Conv2D(50, 3, padding="same"),
tf.keras.layers.MaxPool2D((2, 2)),

# Dense layers
tf.keras.layers.Flatten(),
tf.keras.layers.Dense(120, activation='relu'),
tf.keras.layers.Dense(84, activation='relu'),
tf.keras.layers.Dense(10)
])
else:
model = tf.keras.models.Sequential([
tf.keras.layers.Flatten(input_shape=(28, 28)),
tf.keras.layers.Dense(120, activation='relu'),
tf.keras.layers.Dense(84, activation='relu'),
tf.keras.layers.Dense(10)
])

return model

```

## The Optimizer Model

It's time to implement the optimizer model. You just have to implement the following methods: "build_model",
"fit_dataset_model_" and "score_on_dataset". Those methods must respect their signature and output type. The objective
here is to make the building, the training and the score phase depend on some hyper-parameters. So the optimizer can
use those to find the best set of hp.

```python
class KerasMNISTHpOptimizer(HpOptimizer):
def build_model(self, **hp) -> tf.keras.Model:
model = get_tf_mnist_model(**hp)

model.compile(
optimizer=tf.keras.optimizers.SGD(
learning_rate=hp.get("learning_rate", 1e-3),
nesterov=hp.get("nesterov", True),
momentum=hp.get("momentum", 0.99),
),
loss=tf.keras.losses.SparseCategoricalCrossentropy(from_logits=True),
metrics=[tf.keras.metrics.SparseCategoricalAccuracy()],
)
return model

def fit_dataset_model_(
self,
model: tf.keras.Model,
dataset,
**hp
) -> tf.keras.Model:
history = model.fit(
dataset,
epochs=hp.get("epochs", 1),
verbose=False,
)
return model

def score_on_dataset(
self,
model: tf.keras.Model,
dataset,
**hp
) -> float:
test_loss, test_acc = model.evaluate(dataset, verbose=0)
return test_acc

```

## Execution & Optimization

First thing after creating our classes is to load the dataset in memory.

```python
mnist_train, mnist_test = get_tf_mnist_dataset()
mnist_hp_optimizer = KerasMNISTHpOptimizer()
```

After you will define your hyper-parameters space with a dictionary like this.

```python
hp_space = dict(
epochs=list(range(1, 16)),
learning_rate=np.linspace(1e-4, 1e-1, 50),
nesterov=[True, False],
momentum=np.linspace(0.01, 0.99, 50),
use_conv=[True, False],
)
```

It's time to define your hp search algorithm and give it your budget in time and iteration. Here we will test for
10 minutes and 100 iterations maximum.

```python
param_gen = RandomHpSearch(hp_space, max_seconds=60*10, max_itr=100)
```

Finally, you start the optimization by giving your parameter generator to the optimize method. Note that the
"stop_criterion" argument is to stop the optimization when the given score is reached. It's really useful to save some
time.

```python
save_kwargs = dict(
save_name=f"tf_mnist_hp_opt",
title="Random search: MNIST",
)

param_gen = mnist_hp_optimizer.optimize_on_dataset(
param_gen, mnist_train, save_kwargs=save_kwargs,
stop_criterion=1.0,
)
```

## Testing

Now, you can test the optimized hyper-parameters by fitting again with the full train dataset. Yes with the full
dataset, because in the optimization phase a cross-validation is made which crop your train dataset by half. Plus,
it's time to test the fitted model on the test dataset.

```python
opt_hp = param_gen.get_best_param()

model = mnist_hp_optimizer.build_model(**opt_hp)
mnist_hp_optimizer.fit_dataset_model_(
model, mnist_train, **opt_hp
)

test_acc = mnist_hp_optimizer.score_on_dataset(
model, mnist_test, **opt_hp
)

print(f"test_acc: {test_acc*100:.3f}%")
```

The optimized hyper-parameters:

```python
pp = pprint.PrettyPrinter(indent=4)
pp.pprint(opt_hp)
```

## Visualization

You can visualize the optimization with an interactive html file.

```python
fig = param_gen.write_optimization_to_html(show=True, dark_mode=True, **save_kwargs)
```

## Optimisation table
```python
opt_table = param_gen.get_optimization_table()
```

## Saving ParameterGenerator
```python
param_gen.save_history(**save_kwargs)
save_path = param_gen.save_obj(**save_kwargs)
```

## Loading ParameterGenerator
```python
param_gen = RandomHpSearch.load_obj(save_path)
```

## Re-lunch optimisation with loaded ParameterGenerator
```python
# Change the budget to be able to optimize again
param_gen.max_itr = param_gen.max_seconds + 100
param_gen.max_seconds = param_gen.max_seconds + 60

param_gen = mnist_hp_optimizer.optimize_on_dataset(
param_gen, mnist_train, save_kwargs=save_kwargs,
stop_criterion=1.0, reset_gen=False,
)

opt_hp = param_gen.get_best_param()

print(param_gen.get_optimization_table())
pp.pprint(param_gen.history)
pp.pprint(opt_hp)
```

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# Other examples
Examples on how to use this package are in the folder [./examples](https://github.com/JeremieGince/AutoMLpy/blob/main/examples).
There you can find the previous example with [_Tensorflow_](https://github.com/JeremieGince/AutoMLpy/blob/main/examples/tensorflow_example.ipynb)
and an example with [_pyTorch_](https://github.com/JeremieGince/AutoMLpy/blob/main/examples/pytorch_example.ipynb).

# License
[Apache License 2.0](LICENSE.md)

# Citation
```
@article{Gince,
title={Implémentation du module AutoMLpy, un outil d’apprentissage machine automatique},
author={Jérémie Gince},
year={2021},
publisher={ULaval},
url={https://github.com/JeremieGince/AutoMLpy},
}
```