Update color of scatter chart

Dash Python
1

I’m trying to replicate the following example:

from dash import Dash, html, dcc, Input, Output
import pandas as pd
import plotly.express as px

external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css']

app = Dash(__name__, external_stylesheets=external_stylesheets)

df = pd.read_csv('https://plotly.github.io/datasets/country_indicators.csv')


app.layout = html.Div([
    html.Div([

        html.Div([
            dcc.Dropdown(
                df['Indicator Name'].unique(),
                'Fertility rate, total (births per woman)',
                id='crossfilter-xaxis-column',
            ),
            dcc.RadioItems(
                ['Linear', 'Log'],
                'Linear',
                id='crossfilter-xaxis-type',
                labelStyle={'display': 'inline-block', 'marginTop': '5px'}
            )
        ],
        style={'width': '49%', 'display': 'inline-block'}),

        html.Div([
            dcc.Dropdown(
                df['Indicator Name'].unique(),
                'Life expectancy at birth, total (years)',
                id='crossfilter-yaxis-column'
            ),
            dcc.RadioItems(
                ['Linear', 'Log'],
                'Linear',
                id='crossfilter-yaxis-type',
                labelStyle={'display': 'inline-block', 'marginTop': '5px'}
            )
        ], style={'width': '49%', 'float': 'right', 'display': 'inline-block'})
    ], style={
        'padding': '10px 5px'
    }),

    html.Div([
        dcc.Graph(
            id='crossfilter-indicator-scatter',
            hoverData={'points': [{'customdata': 'Japan'}]}
        )
    ], style={'width': '49%', 'display': 'inline-block', 'padding': '0 20'}),
    html.Div([
        dcc.Graph(id='x-time-series'),
        dcc.Graph(id='y-time-series'),
    ], style={'display': 'inline-block', 'width': '49%'}),

    html.Div(dcc.Slider(
        df['Year'].min(),
        df['Year'].max(),
        step=None,
        id='crossfilter-year--slider',
        value=df['Year'].max(),
        marks={str(year): str(year) for year in df['Year'].unique()}
    ), style={'width': '49%', 'padding': '0px 20px 20px 20px'})
])


@app.callback(
    Output('crossfilter-indicator-scatter', 'figure'),
    Input('crossfilter-xaxis-column', 'value'),
    Input('crossfilter-yaxis-column', 'value'),
    Input('crossfilter-xaxis-type', 'value'),
    Input('crossfilter-yaxis-type', 'value'),
    Input('crossfilter-year--slider', 'value'))
def update_graph(xaxis_column_name, yaxis_column_name,
                 xaxis_type, yaxis_type,
                 year_value):
    dff = df[df['Year'] == year_value]

    fig = px.scatter(x=dff[dff['Indicator Name'] == xaxis_column_name]['Value'],
            y=dff[dff['Indicator Name'] == yaxis_column_name]['Value'],
            hover_name=dff[dff['Indicator Name'] == yaxis_column_name]['Country Name']
            )

    fig.update_traces(customdata=dff[dff['Indicator Name'] == yaxis_column_name]['Country Name'])

    fig.update_xaxes(title=xaxis_column_name, type='linear' if xaxis_type == 'Linear' else 'log')

    fig.update_yaxes(title=yaxis_column_name, type='linear' if yaxis_type == 'Linear' else 'log')

    fig.update_layout(margin={'l': 40, 'b': 40, 't': 10, 'r': 0}, hovermode='closest')

    return fig


def create_time_series(dff, axis_type, title):

    fig = px.scatter(dff, x='Year', y='Value')

    fig.update_traces(mode='lines+markers')

    fig.update_xaxes(showgrid=False)

    fig.update_yaxes(type='linear' if axis_type == 'Linear' else 'log')

    fig.add_annotation(x=0, y=0.85, xanchor='left', yanchor='bottom',
                       xref='paper', yref='paper', showarrow=False, align='left',
                       text=title)

    fig.update_layout(height=225, margin={'l': 20, 'b': 30, 'r': 10, 't': 10})

    return fig


@app.callback(
    Output('x-time-series', 'figure'),
    Input('crossfilter-indicator-scatter', 'hoverData'),
    Input('crossfilter-xaxis-column', 'value'),
    Input('crossfilter-xaxis-type', 'value'))
def update_y_timeseries(hoverData, xaxis_column_name, axis_type):
    country_name = hoverData['points'][0]['customdata']
    dff = df[df['Country Name'] == country_name]
    dff = dff[dff['Indicator Name'] == xaxis_column_name]
    title = '<b>{}</b><br>{}'.format(country_name, xaxis_column_name)
    return create_time_series(dff, axis_type, title)


@app.callback(
    Output('y-time-series', 'figure'),
    Input('crossfilter-indicator-scatter', 'hoverData'),
    Input('crossfilter-yaxis-column', 'value'),
    Input('crossfilter-yaxis-type', 'value'))
def update_x_timeseries(hoverData, yaxis_column_name, axis_type):
    dff = df[df['Country Name'] == hoverData['points'][0]['customdata']]
    dff = dff[dff['Indicator Name'] == yaxis_column_name]
    return create_time_series(dff, axis_type, yaxis_column_name)


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

I want to make the scatter plot colored with country so I did modify this part:

fig = px.scatter(x=dff[dff['Indicator Name'] == xaxis_column_name]['Value'],
        y=dff[dff['Indicator Name'] == yaxis_column_name]['Value'],
        hover_name=dff[dff['Indicator Name'] == yaxis_column_name]['Country Name'],
        color=dff[dff['Indicator Name'] == yaxis_column_name]['Country Name']

        )

But the behavior of scatter doesn’t work any more. when I hover over any country it always selects fixed country.

image
image1904×748 87.1 KB

1 Like
2

Hi there,

I think this is because the custom_data on the scatter plot changed by adding the color parameter.

You can see this when printing the hover_data and the country_name in the def update_y_timeseries() of the original code.

For a quick troubleshoot i changed customdata to hovertext and prevent the initial callbacks for avoiding an error message at startup.

The figure is interactive again and at first sight the behavior is the same as before. This actually makes me wonder, if the customdata is really necessary in the first place. EDIT: I checked, it’s not.

from dash import Dash, html, dcc, Input, Output
import pandas as pd
import plotly.express as px

external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css']

app = Dash(__name__, external_stylesheets=external_stylesheets)

df = pd.read_csv('https://plotly.github.io/datasets/country_indicators.csv')

app.layout = html.Div([
    html.Div([

        html.Div([
            dcc.Dropdown(
                df['Indicator Name'].unique(),
                'Fertility rate, total (births per woman)',
                id='crossfilter-xaxis-column',
            ),
            dcc.RadioItems(
                ['Linear', 'Log'],
                'Linear',
                id='crossfilter-xaxis-type',
                labelStyle={'display': 'inline-block', 'marginTop': '5px'}
            )
        ],
            style={'width': '49%', 'display': 'inline-block'}),

        html.Div([
            dcc.Dropdown(
                df['Indicator Name'].unique(),
                'Life expectancy at birth, total (years)',
                id='crossfilter-yaxis-column'
            ),
            dcc.RadioItems(
                ['Linear', 'Log'],
                'Linear',
                id='crossfilter-yaxis-type',
                labelStyle={'display': 'inline-block', 'marginTop': '5px'}
            )
        ], style={'width': '49%', 'float': 'right', 'display': 'inline-block'})
    ], style={
        'padding': '10px 5px'
    }),

    html.Div([
        dcc.Graph(
            id='crossfilter-indicator-scatter',
            hoverData={'points': [{'customdata': 'Japan'}]}
        )
    ], style={'width': '49%', 'display': 'inline-block', 'padding': '0 20'}),
    html.Div([
        dcc.Graph(id='x-time-series'),
        dcc.Graph(id='y-time-series'),
    ], style={'display': 'inline-block', 'width': '49%'}),

    html.Div(dcc.Slider(
        df['Year'].min(),
        df['Year'].max(),
        step=None,
        id='crossfilter-year--slider',
        value=df['Year'].max(),
        marks={str(year): str(year) for year in df['Year'].unique()}
    ), style={'width': '49%', 'padding': '0px 20px 20px 20px'})
])


@app.callback(
    Output('crossfilter-indicator-scatter', 'figure'),
    Input('crossfilter-xaxis-column', 'value'),
    Input('crossfilter-yaxis-column', 'value'),
    Input('crossfilter-xaxis-type', 'value'),
    Input('crossfilter-yaxis-type', 'value'),
    Input('crossfilter-year--slider', 'value'))
def update_graph(xaxis_column_name, yaxis_column_name,
                 xaxis_type, yaxis_type,
                 year_value):
    dff = df[df['Year'] == year_value]

    fig = px.scatter(
        x=dff[dff['Indicator Name'] == xaxis_column_name]['Value'],
        y=dff[dff['Indicator Name'] == yaxis_column_name]['Value'],
        hover_name=dff[dff['Indicator Name'] == yaxis_column_name]['Country Name'],
        color=dff['Country Name'].unique()
    )

    fig.update_traces(customdata=dff[dff['Indicator Name'] == yaxis_column_name]['Country Name'])

    fig.update_xaxes(title=xaxis_column_name, type='linear' if xaxis_type == 'Linear' else 'log')

    fig.update_yaxes(title=yaxis_column_name, type='linear' if yaxis_type == 'Linear' else 'log')

    fig.update_layout(margin={'l': 40, 'b': 40, 't': 10, 'r': 0}, hovermode='closest')

    return fig


def create_time_series(dff, axis_type, title):
    fig = px.scatter(dff, x='Year', y='Value')

    fig.update_traces(mode='lines+markers')

    fig.update_xaxes(showgrid=False)

    fig.update_yaxes(type='linear' if axis_type == 'Linear' else 'log')

    fig.add_annotation(x=0, y=0.85, xanchor='left', yanchor='bottom',
                       xref='paper', yref='paper', showarrow=False, align='left',
                       text=title)

    fig.update_layout(height=225, margin={'l': 20, 'b': 30, 'r': 10, 't': 10})

    return fig


@app.callback(
    Output('x-time-series', 'figure'),
    Input('crossfilter-indicator-scatter', 'hoverData'),
    Input('crossfilter-xaxis-column', 'value'),
    Input('crossfilter-xaxis-type', 'value'),
    prevent_initial_call=True)
def update_y_timeseries(hoverData, xaxis_column_name, axis_type):
    print(hoverData)
    country_name = hoverData['points'][0]['hovertext']#['customdata']
    print(country_name)
    dff = df[df['Country Name'] == country_name]
    dff = dff[dff['Indicator Name'] == xaxis_column_name]
    title = '<b>{}</b><br>{}'.format(country_name, xaxis_column_name)
    return create_time_series(dff, axis_type, title)


@app.callback(
    Output('y-time-series', 'figure'),
    Input('crossfilter-indicator-scatter', 'hoverData'),
    Input('crossfilter-yaxis-column', 'value'),
    Input('crossfilter-yaxis-type', 'value'),
    prevent_initial_call=True)
def update_x_timeseries(hoverData, yaxis_column_name, axis_type):
    dff = df[df['Country Name'] == hoverData['points'][0]['hovertext']]#['customdata']]
    dff = dff[dff['Indicator Name'] == yaxis_column_name]
    return create_time_series(dff, axis_type, yaxis_column_name)


if __name__ == '__main__':
    app.run_server(debug=True)
1 Like
3

Thanks a lot.

1 Like