specify the meaning of logits in documentation (#238)

change API of train_fn and test_fn (#229)

train_fn(epoch) -> train_fn(epoch, num_env_step)
test_fn(epoch) -> test_fn(epoch, num_env_step)

add PSRL policy (#202)

Add PSRL policy in tianshou/policy/modelbase/psrl.py.

Co-authored-by: n+e <trinkle23897@cmu.edu>

fix critical bugs in MAPolicy and docs update (#207)

- fix a bug in MAPolicy: `buffer.rew = Batch()` doesn't change `buffer.rew` (thanks mypy)
- polish examples/box2d/bipedal_hardcore_sac.py
- several docs update
- format setup.py and bump version to 0.2.7

code refactor for venv (#179)

- Refacor code to remove duplicate code

- Enable async simulation for all vector envs

- Remove `collector.close` and rename `VectorEnv` to `DummyVectorEnv`

The abstraction of vector env changed.

Prior to this pr, each vector env is almost independent.

After this pr, each env is wrapped into a worker, and vector envs differ with their worker type. In fact, users can just use `BaseVectorEnv` with different workers, I keep `SubprocVectorEnv`, `ShmemVectorEnv` for backward compatibility.

Co-authored-by: n+e <463003665@qq.com>
Co-authored-by: magicly <magicly007@gmail.com>

docs fix and v0.2.5 (#156)

* pre

* update docs

* update docs

* $ in bash

* size -> hidden_layer_size

* doctest

* doctest again

* filter a warning

* fix bug

* fix examples

* test fail

* test succ

Improve collector (#125)

* remove multibuf

* reward_metric

* make fileds with empty Batch rather than None after reset

* many fixes and refactor
Co-authored-by: Trinkle23897 <463003665@qq.com>

move atari wrapper to examples and publish v0.2.4 (#124)

* move atari wrapper to examples

* consistency

* change drqn seed since it is quite unstable in current seed

* minor fix

* 0.2.4

fix pdqn