Add stl_plot

[Mr-Geekman]

IMPORTANT: Please do not create a Pull Request without creating an issue first.

Before submitting (must do checklist)

• Did you read the contribution guide?
• Did you update the docs? We use Numpy format for all the methods and classes.
• Did you write any new necessary tests?
• Did you update the CHANGELOG?

Type of Change

• Examples / docs / tutorials / contributors update
• Bug fix (non-breaking change which fixes an issue)
• Improvement (non-breaking change which improves an existing feature)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Proposed Changes

Look #550.

Related Issue

#550.

Closing issues

Closes #550.

[Mr-Geekman]

Example of plot

import pandas as pd
import matplotlib.pyplot as plt

from etna.datasets import TSDataset
from etna.analysis import stl_plot


df = pd.read_csv("examples/data/example_dataset.csv")
df = TSDataset.to_dataset(df)
ts = TSDataset(df, freq="D")

stl_plot(ts=ts, in_column="target", period=7)
plt.savefig("plot.png")

The result:

[codecov-commenter]

Codecov Report

Merging #575 (b04c801) into master (1920257) will decrease coverage by 32.87%.
The diff coverage is 20.00%.

@@             Coverage Diff             @@
##           master     #575       +/-   ##
===========================================
- Coverage   87.21%   54.34%   -32.88%     
===========================================
  Files         119      119               
  Lines        5704     5739       +35     
===========================================
- Hits         4975     3119     -1856     
- Misses        729     2620     +1891     

Impacted Files	Coverage Δ
etna/analysis/eda_utils.py	19.11% <17.64%> (-0.50%)	⬇️
etna/analysis/__init__.py	100.00% <100.00%> (ø)
etna/commands/__init__.py	0.00% <0.00%> (-100.00%)	⬇️
etna/commands/backtest_command.py	0.00% <0.00%> (-96.43%)	⬇️
etna/commands/forecast_command.py	0.00% <0.00%> (-92.00%)	⬇️
etna/commands/__main__.py	0.00% <0.00%> (-87.50%)	⬇️
etna/commands/resolvers.py	0.00% <0.00%> (-80.00%)	⬇️
etna/analysis/outliers/density_outliers.py	22.44% <0.00%> (-75.52%)	⬇️
etna/datasets/datasets_generation.py	26.47% <0.00%> (-73.53%)	⬇️
etna/transforms/timestamp/time_flags.py	27.02% <0.00%> (-72.98%)	⬇️
... and 70 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 1920257...b04c801. Read the comment docs.

[martins0n]

👍