Add code of conduct + update doc (#373)

* Add code of conduct

* Fix DQN doc example

* Update doc (channel-last/first)

* Apply suggestions from code review

Co-authored-by: Anssi <kaneran21@hotmail.com>

* Apply suggestions from code review

Co-authored-by: Adam Gleave <adam@gleave.me>

Co-authored-by: Anssi <kaneran21@hotmail.com>
Co-authored-by: Adam Gleave <adam@gleave.me>

CODE_OF_CONDUCT.md

@@ -0,0 +1,128 @@
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+We as members, contributors, and leaders pledge to make participation in our
+community a harassment-free experience for everyone, regardless of age, body
+size, visible or invisible disability, ethnicity, sex characteristics, gender
+identity and expression, level of experience, education, socio-economic status,
+nationality, personal appearance, race, religion, or sexual identity
+and orientation.
+
+We pledge to act and interact in ways that contribute to an open, welcoming,
+diverse, inclusive, and healthy community.
+
+## Our Standards
+
+Examples of behavior that contributes to a positive environment for our
+community include:
+
+* Demonstrating empathy and kindness toward other people
+* Being respectful of differing opinions, viewpoints, and experiences
+* Giving and gracefully accepting constructive feedback
+* Accepting responsibility and apologizing to those affected by our mistakes,
+  and learning from the experience
+* Focusing on what is best not just for us as individuals, but for the
+  overall community
+
+Examples of unacceptable behavior include:
+
+* The use of sexualized language or imagery, and sexual attention or
+  advances of any kind
+* Trolling, insulting or derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or email
+  address, without their explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+  professional setting
+
+## Enforcement Responsibilities
+
+Community leaders are responsible for clarifying and enforcing our standards of
+acceptable behavior and will take appropriate and fair corrective action in
+response to any behavior that they deem inappropriate, threatening, offensive,
+or harmful.
+
+Community leaders have the right and responsibility to remove, edit, or reject
+comments, commits, code, wiki edits, issues, and other contributions that are
+not aligned to this Code of Conduct, and will communicate reasons for moderation
+decisions when appropriate.
+
+## Scope
+
+This Code of Conduct applies within all community spaces, and also applies when
+an individual is officially representing the community in public spaces.
+Examples of representing our community include using an official e-mail address,
+posting via an official social media account, or acting as an appointed
+representative at an online or offline event.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported to the community leaders responsible for enforcement at
+antonin [dot] raffin [at] dlr [dot] de.
+All complaints will be reviewed and investigated promptly and fairly.
+
+All community leaders are obligated to respect the privacy and security of the
+reporter of any incident.
+
+## Enforcement Guidelines
+
+Community leaders will follow these Community Impact Guidelines in determining
+the consequences for any action they deem in violation of this Code of Conduct:
+
+### 1. Correction
+
+**Community Impact**: Use of inappropriate language or other behavior deemed
+unprofessional or unwelcome in the community.
+
+**Consequence**: A private, written warning from community leaders, providing
+clarity around the nature of the violation and an explanation of why the
+behavior was inappropriate. A public apology may be requested.
+
+### 2. Warning
+
+**Community Impact**: A violation through a single incident or series
+of actions.
+
+**Consequence**: A warning with consequences for continued behavior. No
+interaction with the people involved, including unsolicited interaction with
+those enforcing the Code of Conduct, for a specified period of time. This
+includes avoiding interactions in community spaces as well as external channels
+like social media. Violating these terms may lead to a temporary or
+permanent ban.
+
+### 3. Temporary Ban
+
+**Community Impact**: A serious violation of community standards, including
+sustained inappropriate behavior.
+
+**Consequence**: A temporary ban from any sort of interaction or public
+communication with the community for a specified period of time. No public or
+private interaction with the people involved, including unsolicited interaction
+with those enforcing the Code of Conduct, is allowed during this period.
+Violating these terms may lead to a permanent ban.
+
+### 4. Permanent Ban
+
+**Community Impact**: Demonstrating a pattern of violation of community
+standards, including sustained inappropriate behavior,  harassment of an
+individual, or aggression toward or disparagement of classes of individuals.
+
+**Consequence**: A permanent ban from any sort of public interaction within
+the community.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage],
+version 2.0, available at
+https://www.contributor-covenant.org/version/2/0/code_of_conduct.html.
+
+Community Impact Guidelines were inspired by [Mozilla's code of conduct
+enforcement ladder](https://github.com/mozilla/diversity).
+
+[homepage]: https://www.contributor-covenant.org
+
+For answers to common questions about this code of conduct, see the FAQ at
+https://www.contributor-covenant.org/faq. Translations are available at
+https://www.contributor-covenant.org/translations.

docs/guide/callbacks.rst

@@ -185,6 +185,11 @@ It will save the best model if ``best_model_save_path`` folder is specified and
 	You can pass a child callback via the ``callback_on_new_best`` argument. It will be triggered each time there is a new best model.
 
 
+.. warning::
+
+  You need to make sure that ``eval_env`` is wrapped the same way as the training environment, for instance using the ``VecTransposeImage`` wrapper if you have a channel-last image as input.
+  The ``EvalCallback`` class outputs a warning if it is not the case.
+
 
 .. code-block:: python
 

docs/guide/custom_env.rst

@@ -13,6 +13,12 @@ That is to say, your environment must implement the following methods (and inher
 	channel-first or channel-last.
 
 
+.. note::
+
+  Although SB3 supports both channel-last and channel-first images as input, we recommend using the channel-first convention when possible.
+  Under the hood, when a channel-last image is passed, SB3 uses a ``VecTransposeImage`` wrapper to re-order the channels.
+
+
 
 .. code-block:: python
 
@@ -29,9 +35,9 @@ That is to say, your environment must implement the following methods (and inher
       # They must be gym.spaces objects
       # Example when using discrete actions:
       self.action_space = spaces.Discrete(N_DISCRETE_ACTIONS)
-      # Example for using image as input (can be channel-first or channel-last):
+      # Example for using image as input (channel-first; channel-last also works):
       self.observation_space = spaces.Box(low=0, high=255,
-                                          shape=(HEIGHT, WIDTH, N_CHANNELS), dtype=np.uint8)
+                                          shape=(N_CHANNELS, HEIGHT, WIDTH), dtype=np.uint8)
 
     def step(self, action):
       ...

docs/misc/changelog.rst

@@ -23,11 +23,14 @@ Deprecations:
 Others:
 ^^^^^^^
 - Added ``flake8-bugbear`` to tests dependencies to find likely bugs
+- Added Code of Conduct
 
 Documentation:
 ^^^^^^^^^^^^^^
 - Added gym pybullet drones project (@JacopoPan)
 - Added link to SuperSuit in projects (@justinkterry)
+- Fixed DQN example (thanks @ltbd78)
+- Clarify channel-first/channel-last recommendation
 
 
 Release 1.0 (2021-03-15)
@@ -637,4 +640,4 @@ And all the contributors:
 @tirafesi @blurLake @koulakis @joeljosephjin @shwang @rk37 @andyshih12 @RaphaelWag @xicocaio
 @diditforlulz273 @liorcohen5 @ManifoldFR @mloo3 @SwamyDev @wmmc88 @megan-klaiber @thisray
 @tfederico @hn2 @LucasAlegre @AptX395 @zampanteymedio @decodyng @ardabbour @lorenz-h @mschweizer @lorepieri8
-@ShangqunYu @PierreExeter @JacopoPan
+@ShangqunYu @PierreExeter @JacopoPan @ltbd78

docs/modules/dqn.rst

@@ -61,11 +61,11 @@ Example
 
   model = DQN("MlpPolicy", env, verbose=1)
   model.learn(total_timesteps=10000, log_interval=4)
-  model.save("dqn_pendulum")
+  model.save("dqn_cartpole")
 
   del model # remove to demonstrate saving and loading
 
-  model = DQN.load("dqn_pendulum")
+  model = DQN.load("dqn_cartpole")
 
   obs = env.reset()
   while True: