How to use Neptune with Altair#

Altair is a declarative statistical visualization library for Python. With Neptune, you can log and display Altair charts as interactive HTML.

Altair chart in Neptune

See in Neptune Example script

Before you start#

Sign up at neptune.ai/register.
Create a project for storing your metadata.
Have Altair and Neptune installed:
```
pip install -U altair neptune
```

Tip

To follow the guide without any setup, run the example notebook in Colab

Altair logging example#

Import Neptune and start a run:

import neptune

run = neptune.init_run() # (1)!

If you haven't set up your credentials, you can log anonymously:

neptune.init_run(
    api_token=neptune.ANONYMOUS_API_TOKEN,
    project="common/plotting",
)

Install vega-datasets to access sample data:
```
pip install vega_datasets
```

Create a sample figure using data from vega_datasets.data.cars():

import altair as alt
from vega_datasets import data

source = data.cars()

brush = alt.selection_interval()

points = (
    alt.Chart(source)
    .mark_point()
    .encode(
        x="Horsepower:Q",
        y="Miles_per_Gallon:Q",
        color=alt.condition(brush, "Origin:N", alt.value("lightgray")),
    )
    .add_params(brush)
)

bars = (
    alt.Chart(source)
    .mark_bar()
    .encode(y="Origin:N", color="Origin:N", x="count(Origin):Q")
    .transform_filter(brush)
)

chart = points & bars

Upload the chart:
```
run["interactive_img"].upload(chart)
```
To stop the connection to Neptune and sync all data, call the stop() method:
```
run.stop()
```
Run your script as you normally would.

To open the run, click the Neptune link that appears in the console output.

[neptune] [info ] Neptune initialized. Open in the app: https://app.neptune.ai/workspace/project/e/RUN-1

Result

The resulting chart is logged as an HTML object.

You can view it in the All metadata section.