.. 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 <https://github.com/twitter/dict_minimize>`_, `PyPI <https://pypi.org/project/dict-minimize/>`_, and `Read the Docs <https://dict-minimize.readthedocs.io/en/latest/>`_.
Example Usage
=============
In these examples we optimize a modified `Rosenbrock <https://en.wikipedia.org/wiki/Rosenbrock_function>`_ 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 <https://github.com/twitter/dict_minimize>`_ is hosted on GitHub.
The `documentation <https://dict-minimize.readthedocs.io/en/latest/>`_ is hosted at Read the Docs.
Installable from `PyPI <https://pypi.org/project/dict-minimize/>`_.
License
=======
This project is licensed under the Apache 2 License - see the LICENSE file for details.