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Evidently and DVCLive
Log Evidently metrics with DVC via DVCLive.
TL;DR: You can use Evidently to calculate metrics, and DVCLive to log and view the results.
Jupyter notebook with en example:
Evidently calculates a rich set of metrics and statistical tests. You can choose any of the pre-built reports or combine individual metrics to define what you want to measure. For example, you can evaluate prediction drift and feature drift together.
You can then generate the calculation output in a Python dictionary format. You should explicitly define which parts of the output to send to DVCLive Tracking.
Install DVCLive, Evidently, and pandas (to handle the data) in your Python environment:
$ pip install dvc dvclive evidently pandas
Load the data from UCI repository and save it locally. For demonstration purposes, we treat this data as the input data for a live model. To use with production models, you should make your prediction logs available.
$ wget https://archive.ics.uci.edu/static/public/275/bike+sharing+dataset.zip
$ unzip bike+sharing+dataset.zip
import pandas as pd
df = pd.read_csv("raw_data/day.csv", header=0, sep=',', parse_dates=['dteday'])
df.head()
This is how it looks: 
You should specify the categorical and numerical features so that Evidently performs the correct statistical test for each of them. While Evidently can parse the data structure automatically, manually specifying the column type can minimize errors.
from evidently.pipeline.column_mapping import ColumnMapping
data_columns = ColumnMapping()
data_columns.numerical_features = ['weathersit', 'temp', 'atemp', 'hum', 'windspeed']
data_columns.categorical_features = ['holiday', 'workingday']
Specify which metrics you want to calculate. In this case, you can generate the Data Drift report and log the drift score for each feature.
from evidently.report import Report
from evidently.metric_preset import DataDriftPreset
def eval_drift(reference, production, column_mapping):
data_drift_report = Report(metrics=[DataDriftPreset()])
data_drift_report.run(
reference_data=reference, current_data=production, column_mapping=column_mapping
)
report = data_drift_report.as_dict()
drifts = []
for feature in (
column_mapping.numerical_features + column_mapping.categorical_features
):
drifts.append(
(
feature,
report["metrics"][1]["result"]["drift_by_columns"][feature][
"drift_score"
],
)
)
return drifts
You can adapt what you want to calculate by selecting a different Preset or Metric from those available in Evidently.
Specify the period that is considered reference: Evidently will use it as the base for the comparison. Then, you should choose the periods to treat as experiments. This emulates the production model runs.
#set reference dates
reference_dates = ('2011-01-01 00:00:00','2011-01-28 23:00:00')
#set experiment batches dates
experiment_batches = [
('2011-01-01 00:00:00','2011-01-29 23:00:00'),
('2011-01-29 00:00:00','2011-02-07 23:00:00'),
('2011-02-07 00:00:00','2011-02-14 23:00:00'),
('2011-02-15 00:00:00','2011-02-21 23:00:00'),
]
There are two ways to track the results of Evidently with DVCLive:
- 1.you can save the results of each item in the batch in one single experiment (each experiment corresponds to a git commit), in separate steps
- 2.or you can save the result of each item in the batch as a separate experiment
We will demonstrate both, and show you how to inspect the results regardless of your IDE. However, if you are using VSCode, we recommend using the DVC extension for VS Code to inspect the results.
from dvclive import Live
with Live() as live:
for date in experiment_batches:
live.log_param("begin", date[0])
live.log_param("end", date[1])
metrics = eval_drift(
df.loc[df.dteday.between(reference_dates[0], reference_dates[1])],
df.loc[df.dteday.between(date[0], date[1])],
column_mapping=data_columns,
)
for feature in metrics:
live.log_metric(feature[0], round(feature[1], 3))
live.next_step()
You can then inspect the results using
$ dvc plots show
and inspecting the resulting 
dvc_plots/index.html, which should look like this: In a Jupyter notebook environment, you can show the plots as a cell output simply by using
Live(report="notebook").from dvclive import Live
for step, date in enumerate(experiment_batches):
with Live() as live:
live.log_param("begin", date[0])
live.log_param("end", date[1])
live.log_param("step", step)
metrics = eval_drift(
df.loc[df.dteday.between(reference_dates[0], reference_dates[1])],
df.loc[df.dteday.between(date[0], date[1])],
column_mapping=data_columns,
)
for feature in metrics:
live.log_metric(feature[0], round(feature[1], 3))
You can the inspect the results using
$ dvc exp show
────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
Experiment Created weathersit temp atemp hum windspeed holiday workingday step begin end
────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
workspace - 0.231 0 0 0.062 0.012 0.275 0.593 3 2011-02-15 00:00:00 2011-02-21 23:00:00
master 10:02 AM - - - - - - - - - -
├── a96b45c [muggy-rand] 10:02 AM 0.231 0 0 0.062 0.012 0.275 0.593 3 2011-02-15 00:00:00 2011-02-21 23:00:00
├── 78c6668 [pawky-arcs] 10:02 AM 0.155 0.399 0.537 0.684 0.611 0.588 0.699 2 2011-02-07 00:00:00 2011-02-14 23:00:00
├── c1dd720 [joint-wont] 10:02 AM 0.779 0.098 0.107 0.03 0.171 0.545 0.653 1 2011-01-29 00:00:00 2011-02-07 23:00:00
└── d0ddb8d [osmic-impi] 10:02 AM 0.985 1 1 1 1 0.98 0.851 0 2011-01-01 00:00:00 2011-01-29 23:00:00
────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
import dvc.api
dvc.api.exp_show()
Last modified 1mo ago