.. -*- mode: rst -*-
Working with Dash and Plotly
============================
From `Plotly's getting start guide: `_ "The plotly Python library is an interactive, open-source plotting library that supports over 40 unique chart types covering a wide range of statistical, financial, geographic, scientific, and 3-dimensional use-cases."
These tools are usable in jupyter notebooks and can also be ran as their own standalone apps using plotly-dash.
Below are two examples using the standard API and the Arrow enabled API to retrieve data as a pandas.DataFrame, and then plotting the results.
These examples are based off of the `minimal dash app `_.
Non-Multistream API
-------------------
.. code-block:: python
from dash import Dash, html, dcc, callback, Output, Input
import plotly.express as px
import pandas as pd
import btrdb
conn = btrdb.connect()
streams = conn.streams_in_collection("YOUR_COLLECTION_HERE")
streamset = conn.streams(*[s.uuid for s in streams])
latest = streamset.latest()
end = min([pt.time for pt in latest])
start = end - btrdb.utils.timez.ns_delta(minutes=5)
df = streamset.filter(start=start, end=end).to_dataframe()
app = Dash(__name__)
app.layout = html.Div([
html.H1(children='Title of Dash App', style={'textAlign':'center'}),
dcc.Dropdown(df.columns, id='dropdown-selection'),
dcc.Graph(id='graph-content')
])
@callback(
Output('graph-content', 'figure'),
Input('dropdown-selection', 'value')
)
def update_graph(value):
dff = df[value]
return px.line(dff, x=dff.index, y=value)
if __name__ == '__main__':
app.run(debug=True)
Multistream API
---------------
.. code-block:: python
from dash import Dash, html, dcc, callback, Output, Input
import plotly.express as px
import pandas as pd
import btrdb
conn = btrdb.connect()
streams = conn.streams_in_collection("YOUR_COLLECTION_HERE")
streamset = conn.streams(*[s.uuid for s in streams])
latest = streamset.latest()
end = min([pt.time for pt in latest])
start = end - btrdb.utils.timez.ns_delta(minutes=5)
df = streamset.filter(start=start, end=end).arrow_to_dataframe()
df = df.set_index('time')
app = Dash(__name__)
app.layout = html.Div([
html.H1(children='Title of Dash App', style={'textAlign':'center'}),
dcc.Dropdown(df.columns, id='dropdown-selection'),
dcc.Graph(id='graph-content')
])
@callback(
Output('graph-content', 'figure'),
Input('dropdown-selection', 'value')
)
def update_graph(value):
dff = df[value]
return px.line(dff, x=dff.index, y=value)
if __name__ == '__main__':
app.run(debug=True)