Change the size of Dash Graph in Python

Dash is a popular Python framework for building interactive web applications, particularly for data visualization. Developed by Plotly, Dash allows users to create web-based dashboards with minimal code. One common requirement when working with Dash is adjusting the size of graphs to fit the layout and design needs of the dashboard.

What is a Dash Graph?

A Dash graph is a data visualization component created using the Plotly library within a Dash application. These graphs can be interactive and customized in various ways, including their size, colors, layout, and interactivity features. Dash graphs are typically used to represent data insights in a clear and visually appealing manner. Make sure you have installed all the required Dash packages correctly. Run the following commands to ensure everything is up to date:

pip install dash dash-core-components dash-html-components

Methods to Change the Window Size of Your Dash Graph

Example 1: Using the style Attribute

One of the simplest ways to change the size of a Dash graph is by using the style attribute in the dcc.Graph component. This method allows you to set the width and height of the graph directly.

import dash
import dash_core_components as dcc
import dash_html_components as html

# Create a Dash application
app = dash.Dash(__name__)

# Define the layout of the app
app.layout = html.Div([
    dcc.Graph(
        id='example-graph',
        figure={
            'data': [{'x': [1, 2, 3], 'y': [4, 1, 2], 'type': 'bar', 'name': 'Example'}],
            'layout': {'title': 'Example Graph'}
        },
        style={'width': '50%', 'height': '500px'}
    )
])

# Run the app
if __name__ == '__main__':
    app.run_server(debug=True)

In this example, the style attribute sets the width to 50% of the parent container and the height to 500 pixels.

Output:

Example 2: Using Plotly Layout

Another way to change the size of your Dash graph is by adjusting the layout properties in the Plotly figure. The width and height properties of the layout dictionary can be used to set the size of the graph.

import dash
import dash_core_components as dcc
import dash_html_components as html
import plotly.graph_objs as go

# Create a Dash application
app = dash.Dash(__name__)

# Define the layout of the app
app.layout = html.Div([
    dcc.Graph(
        id='example-graph',
        figure={
            'data': [go.Bar(x=[1, 2, 3], y=[4, 1, 2], name='Example')],
            'layout': go.Layout(
                title='Example Graph',
                width=600,
                height=400
            )
        }
    )
])

# Run the app
if __name__ == '__main__':
    app.run_server(debug=True)

Here, the width and height properties in the layout dictionary are used to set the size of the graph to 600 by 400 pixels.

Example 3: Responsive Graph Sizing

To create a graph that dynamically adjusts its size based on the window size, you can use CSS and the style attribute together. This approach makes the graph responsive and adaptable to different screen sizes.

import dash
import dash_core_components as dcc
import dash_html_components as html

# Create a Dash application
app = dash.Dash(__name__)

# Define the layout of the app
app.layout = html.Div([
    dcc.Graph(
        id='example-graph',
        figure={
            'data': [{'x': [1, 2, 3], 'y': [4, 1, 2], 'type': 'bar', 'name': 'Example'}],
            'layout': {'title': 'Example Graph'}
        },
        style={'width': '100%', 'height': '100vh'}  # 100% width and 100% viewport height
    )
], style={'height': '100vh'})  # Ensure the parent div takes the full viewport height

# Run the app
if __name__ == '__main__':
    app.run_server(debug=True)

In this example, the graph will take up 100% of the width and height of the viewport, making it fully responsive to changes in window size.

Output:

Conclusion

Changing the size of your Dash graph is crucial for creating a visually appealing and user-friendly dashboard. Whether you prefer using the style attribute, adjusting the Plotly layout properties, or creating a responsive design with CSS, Dash provides flexible methods to customize the size of your graphs. These examples demonstrate how to effectively resize your graphs to fit the specific needs of your Dash application.