strategy.run(episodes=episodes, render_mode="chart") -> IndexError: index -1 is out of bounds for axis 0 with size 0

[tempsvps]

System information

• OS Platform and Distribution Windows 10
• TensorTrade version:
• TensorFlow version: 1.15.0
• Python version: 3.6

Describe the current behavior
Testing new chart render. Errror:
"C:\Users\Miner\Documents\GitHub!MyTensorTrader\tensortrade\environments\render\matplotlib_trading_chart.py", line 132, in render
net_worth = round(net_worths[-1], 2)
IndexError: index -1 is out of bounds for axis 0 with size 0

Describe the expected behavior

Code to reproduce the issue
episodes = 1
performance = strategy.run(episodes=episodes, render_mode="chart")


Other info / logs

Traceback (most recent call last):
File "C:/Users/Miner/Documents/GitHub/!MyTensorTrader/main.py", line 83, in
performance = strategy.run(episodes=episodes, render_mode="chart")
File "C:\Users\Miner\Documents\GitHub!MyTensorTrader\tensortrade\strategies\stable_baselines_strategy.py", line 116, in run
self._environment.render(mode=render_mode)
File "C:\ProgramData\Anaconda3\envs\PYTrade\lib\site-packages\stable_baselines\common\vec_env\dummy_vec_env.py", line 64, in render
return self.envs[0].render(*args, **kwargs)
File "C:\Users\Miner\Documents\GitHub!MyTensorTrader\tensortrade\environments\trading_environment.py", line 248, in render
self.exchange.trades)
File "C:\Users\Miner\Documents\GitHub!MyTensorTrader\tensortrade\environments\render\matplotlib_trading_chart.py", line 132, in render
net_worth = round(net_worths[-1], 2)
IndexError: index -1 is out of bounds for axis 0 with size 0

[kuaige99]

There was a bug: environment will be reset before render.
stable-baselines will reset env in the _environment.step when environments is done.

The solution: in render funtion modify code
if self.viewer is not None and self._current_step > 1:

[notadamking]

Fixed in #125