r - 在 Plotly 中的点悬停上显示图像

Question

Plotly 允许您在将鼠标悬停在散点图上的某个点上时显示文本字段。当用户悬停或点击它时，是否可以显示与每个点相关联的图像？我主要只是使用网络界面，但我可以ggplot从 R推送我的。

Answer 1

不幸的是，目前没有简单的方法可以在图表上悬停时显示图像。

如果您愿意学习一些 javascript，plotly 的embed API允许您自定义悬停（以及单击）交互性。

这是一个自定义悬停交互的示例，在绘图图顶部显示图像。可以在此处找到 javascript 源代码。

Answer 2

Plotly lib 现在可以使用悬停图像。这是一个示例：

from dash import Dash, dcc, html, Input, Output, no_update
import plotly.graph_objects as go
import pandas as pd

# Small molcule drugbank dataset
# Source: https://raw.githubusercontent.com/plotly/dash-sample-apps/main/apps/dash-drug-discovery/data/small_molecule_drugbank.csv'
data_path = 'datasets/small_molecule_drugbank.csv'

df = pd.read_csv(data_path, header=0, index_col=0)

fig = go.Figure(data=[
    go.Scatter(
        x=df["LOGP"],
        y=df["PKA"],
        mode="markers",
        marker=dict(
            colorscale='viridis',
            color=df["MW"],
            size=df["MW"],
            colorbar={"title": "Molecular<br>Weight"},
            line={"color": "#444"},
            reversescale=True,
            sizeref=45,
            sizemode="diameter",
            opacity=0.8,
        )
    )
])

# turn off native plotly.js hover effects - make sure to use
# hoverinfo="none" rather than "skip" which also halts events.
fig.update_traces(hoverinfo="none", hovertemplate=None)

fig.update_layout(
    xaxis=dict(title='Log P'),
    yaxis=dict(title='pkA'),
    plot_bgcolor='rgba(255,255,255,0.1)'
)

app = Dash(__name__)

app.layout = html.Div([
    dcc.Graph(id="graph-basic-2", figure=fig, clear_on_unhover=True),
    dcc.Tooltip(id="graph-tooltip"),
])


@app.callback(
    Output("graph-tooltip", "show"),
    Output("graph-tooltip", "bbox"),
    Output("graph-tooltip", "children"),
    Input("graph-basic-2", "hoverData"),
)
def display_hover(hoverData):
    if hoverData is None:
        return False, no_update, no_update

    # demo only shows the first point, but other points may also be available
    pt = hoverData["points"][0]
    bbox = pt["bbox"]
    num = pt["pointNumber"]

    df_row = df.iloc[num]
    img_src = df_row['IMG_URL']
    name = df_row['NAME']
    form = df_row['FORM']
    desc = df_row['DESC']
    if len(desc) > 300:
        desc = desc[:100] + '...'

    children = [
        html.Div([
            html.Img(src=img_src, style={"width": "100%"}),
            html.H2(f"{name}", style={"color": "darkblue"}),
            html.P(f"{form}"),
            html.P(f"{desc}"),
        ], style={'width': '200px', 'white-space': 'normal'})
    ]

    return True, bbox, children


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

更多信息：https ://dash.plotly.com/dash-core-components/tooltip