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Figurewidget App

doc/python/figurewidget-app.md

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NYC Flights Database

python
import datetime
import numpy as np
import pandas as pd

import plotly.graph_objects as go
from ipywidgets import widgets

We'll be making an application to take a look at delays from all flights out of NYC in the year 2013.

python
df = pd.read_csv(
    'https://raw.githubusercontent.com/yankev/testing/master/datasets/nycflights.csv')
df = df.drop(df.columns[[0]], axis=1)
python
df.sample(3)

Let's get the set of all the airlines, so that we can type the right things into the search box later.

python
df['carrier'].unique()

Let's assign the widgets that we're going to be using in our app. In general all these widgets will be used to filter the data set, and thus what we visualize.

python
month = widgets.IntSlider(
    value=1.0,
    min=1.0,
    max=12.0,
    step=1.0,
    description='Month:',
    continuous_update=False
)

use_date = widgets.Checkbox(
    description='Date: ',
    value=True,
)

container = widgets.HBox(children=[use_date, month])

textbox = widgets.Dropdown(
    description='Airline:   ',
    value='DL',
    options=df['carrier'].unique().tolist()
)

origin = widgets.Dropdown(
    options=list(df['origin'].unique()),
    value='LGA',
    description='Origin Airport:',
)


# Assign an empty figure widget with two traces
trace1 = go.Histogram(x=df['arr_delay'], opacity=0.75, name='Arrival Delays')
trace2 = go.Histogram(x=df['dep_delay'], opacity=0.75, name='Departure Delays')
g = go.FigureWidget(data=[trace1, trace2],
                    layout=go.Layout(
                        title=dict(
                            text='NYC FlightDatabase'
                        ),
                        barmode='overlay'
                    ))

Let now write a function that will handle the input from the widgets, and alter the state of the graph.

python
def validate():
    if origin.value in df['origin'].unique() and textbox.value in df['carrier'].unique():
        return True
    else:
        return False


def response(change):
    if validate():
        if use_date.value:
            filter_list = [i and j and k for i, j, k in
                           zip(df['month'] == month.value, df['carrier'] == textbox.value,
                               df['origin'] == origin.value)]
            temp_df = df[filter_list]

        else:
            filter_list = [i and j for i, j in
                           zip(df['carrier'] == 'DL', df['origin'] == origin.value)]
            temp_df = df[filter_list]
        x1 = temp_df['arr_delay']
        x2 = temp_df['dep_delay']
        with g.batch_update():
            g.data[0].x = x1
            g.data[1].x = x2
            g.layout.barmode = 'overlay'
            g.layout.xaxis.title = 'Delay in Minutes'
            g.layout.yaxis.title = 'Number of Delays'


origin.observe(response, names="value")
textbox.observe(response, names="value")
month.observe(response, names="value")
use_date.observe(response, names="value")

Time to try the app out!!

python
container2 = widgets.HBox([origin, textbox])
widgets.VBox([container,
              container2,
              g])
html

Reference

python
help(go.FigureWidget)