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https://github.com/twitter/dict_minimize

Access scipy optimizers from your favorite deep learning framework.
https://github.com/twitter/dict_minimize

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Access scipy optimizers from your favorite deep learning framework.

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README

        

.. figure:: https://user-images.githubusercontent.com/28273671/90945755-c2935580-e3db-11ea-9ba9-dbb054834b02.png
:alt: Rosenbrock

*************************
The Dict Minimize Package
*************************

Access ``scipy`` optimizers from your favorite deep learning framework.

Installation
============

Only ``Python>=3.6`` is officially supported, but older versions of Python likely work as well.

The core package itself can be installed with:

.. code-block:: bash

pip install dict_minimize

To also get the dependencies for all the supported frameworks (torch, JAX, tensorflow) in the README install with

.. code-block:: bash

pip install dict_minimize[framework]

See the `GitHub `_, `PyPI `_, and `Read the Docs `_.

Example Usage
=============

In these examples we optimize a modified `Rosenbrock `_ function.
However, the arguments have been split into two chunks and stored as two entries in a dictionary.
This is to illustrate how this package optimizes *dictionaries* of (tensor) parameters rather then vectors.
We also pass in an extra ``shift`` argument to demonstrate how ``minimize`` allows extra constant arguments to be passed into the objective.

PyTorch
-------

.. code-block:: python

import torch
from dict_minimize.torch_api import minimize

def rosen_obj(params, shift):
"""Based on augmented Rosenbrock from botorch."""
X, Y = params["x_half_a"], params["x_half_b"]
X = X - shift
Y = Y - shift
obj = 100 * (X[1] - X[0] ** 2) ** 2 + 100 * (Y[1] - Y[0] ** 2) ** 2
return obj

def d_rosen_obj(params, shift):
obj = rosen_obj(params, shift=shift)
da, db = torch.autograd.grad(obj, [params["x_half_a"], params["x_half_b"]])
d_obj = OrderedDict([("x_half_a", da), ("x_half_b", db)])
return obj, d_obj

torch.manual_seed(123)

n_a = 2
n_b = 2
shift = -1.0

params = OrderedDict([("x_half_a", torch.randn((n_a,))), ("x_half_b", torch.randn((n_b,)))])

params = minimize(d_rosen_obj, params, args=(shift,), method="L-BFGS-B", options={"disp": True})

TensorFlow
----------

.. code-block:: python

import tensorflow as tf
from dict_minimize.tensorflow_api import minimize

def rosen_obj(params, shift):
"""Based on augmented Rosenbrock from botorch."""
X, Y = params["x_half_a"], params["x_half_b"]
X = X - shift
Y = Y - shift
obj = 100 * (X[1] - X[0] ** 2) ** 2 + 100 * (Y[1] - Y[0] ** 2) ** 2
return obj

def d_rosen_obj(params, shift):
with tf.GradientTape(persistent=True) as t:
t.watch(params["x_half_a"])
t.watch(params["x_half_b"])

obj = rosen_obj(params, shift=shift)

da = t.gradient(obj, params["x_half_a"])
db = t.gradient(obj, params["x_half_b"])
d_obj = OrderedDict([("x_half_a", da), ("x_half_b", db)])
del t # Explicitly drop the reference to the tape
return obj, d_obj

tf.random.set_seed(123)

n_a = 2
n_b = 2
shift = -1.0

params = OrderedDict([("x_half_a", tf.random.normal((n_a,))), ("x_half_b", tf.random.normal((n_b,)))])

params = minimize(d_rosen_obj, params, args=(shift,), method="L-BFGS-B", options={"disp": True})

NumPy
-----

.. code-block:: python

import numpy as np
from scipy.optimize import rosen, rosen_der
from dict_minimize.numpy_api import minimize

def rosen_obj(params, shift):
val = rosen(params["x_half_a"] - shift) + rosen(params["x_half_b"] - shift)

dval = OrderedDict(
[
("x_half_a", rosen_der(params["x_half_a"] - shift)),
("x_half_b", rosen_der(params["x_half_b"] - shift)),
]
)
return val, dval

np.random.seed(0)

n_a = 3
n_b = 5
shift = -1.0

params = OrderedDict([("x_half_a", np.random.randn(n_a)), ("x_half_b", np.random.randn(n_b))])

params = minimize(rosen_obj, params, args=(shift,), method="L-BFGS-B", options={"disp": True})

JAX
---

.. code-block:: python

from jax import random, value_and_grad
import jax.numpy as np
from dict_minimize.jax_api import minimize

def rosen(x):
r = np.sum(100.0 * (x[1:] - x[:-1] ** 2.0) ** 2.0 + (1 - x[:-1]) ** 2.0, axis=0)
return r

def rosen_obj(params, shift):
val = rosen(params["x_half_a"] - shift) + rosen(params["x_half_b"] - shift)
return val

n_a = 3
n_b = 5
shift = -1.0

# Jax makes it this simple:
d_rosen_obj = value_and_grad(rosen_obj, argnums=0)

# Setup randomness in JAX
key = random.PRNGKey(0)
key, subkey_a = random.split(key)
key, subkey_b = random.split(key)

params = OrderedDict(
[("x_half_a", random.normal(subkey_a, shape=(n_a,))), ("x_half_b", random.normal(subkey_b, shape=(n_b,)))]
)

params = minimize(d_rosen_obj, params, args=(shift,), method="L-BFGS-B", options={"disp": True})

Contributing
============

The following instructions have been tested with Python 3.7.4 on Mac OS (10.14.6).

Install in editable mode
------------------------

First, define the variables for the paths we will use:

.. code-block:: bash

GIT=/path/to/where/you/put/repos
ENVS=/path/to/where/you/put/virtualenvs

Then clone the repo in your git directory ``$GIT``:

.. code-block:: bash

cd $GIT
git clone https://github.com/twitter/dict_minimize.git

Inside your virtual environments folder ``$ENVS``, make the environment:

.. code-block:: bash

cd $ENVS
virtualenv dict_minimize --python=python3.7
source $ENVS/dict_minimize/bin/activate

Now we can install the pip dependencies. Move back into your git directory and run

.. code-block:: bash

cd $GIT/dict_minimize
pip install -r requirements/base.txt
pip install -e . # Install the package itself

Contributor tools
-----------------

First, we need to setup some needed tools:

.. code-block:: bash

cd $ENVS
virtualenv dict_minimize_tools --python=python3.7
source $ENVS/dict_minimize_tools/bin/activate
pip install -r $GIT/dict_minimize/requirements/tools.txt

To install the pre-commit hooks for contributing run (in the ``dict_minimize_tools`` environment):

.. code-block:: bash

cd $GIT/dict_minimize
pre-commit install

To rebuild the requirements, we can run:

.. code-block:: bash

cd $GIT/dict_minimize

# Check if there any discrepancies in the .in files
pipreqs dict_minimize/core/ --diff requirements/base.in
pipreqs dict_minimize/ --diff requirements/frameworks.in
pipreqs tests/ --diff requirements/tests.in
pipreqs docs/ --diff requirements/docs.in

# Regenerate the .txt files from .in files
pip-compile-multi --no-upgrade

Generating the documentation
----------------------------

First setup the environment for building with ``Sphinx``:

.. code-block:: bash

cd $ENVS
virtualenv dict_minimize_docs --python=python3.7
source $ENVS/dict_minimize_docs/bin/activate
pip install -r $GIT/dict_minimize/requirements/docs.txt

Then we can do the build:

.. code-block:: bash

cd $GIT/dict_minimize/docs
make all
open _build/html/index.html

Documentation will be available in all formats in ``Makefile``. Use ``make html`` to only generate the HTML documentation.

Running the tests
-----------------

The tests for this package can be run with:

.. code-block:: bash

cd $GIT/dict_minimize
./local_test.sh

The script creates an environment using the requirements found in ``requirements/test.txt``.
A code coverage report will also be produced in ``$GIT/dict_minimize/htmlcov/index.html``.

Deployment
----------

The wheel (tar ball) for deployment as a pip installable package can be built using the script:

.. code-block:: bash

cd $GIT/dict_minimize/
./build_wheel.sh

This script will only run if the git repo is clean, i.e., first run ``git clean -x -ff -d``.

Links
=====

The `source `_ is hosted on GitHub.

The `documentation `_ is hosted at Read the Docs.

Installable from `PyPI `_.

License
=======

This project is licensed under the Apache 2 License - see the LICENSE file for details.