创建px.scatter后插入趋势线(图)

Question

NAME="Ubuntu“VERSION="20.04.3 LTS (焦点Fossa)”

Streamlit，1.12.0版

Python 3.8.10

plotly==5.10.0

我有一个Streamlit仪表板，它使用plotly express制作图表。仪表板允许用户选择不同的选项，图表在动态的情况下使用这些选项重新创建。

其中一个选项是添加趋势线，但是我只在创建无花果(作为px.scatter()的一个选项)时找到了这样做的方法。

是否有方法在调用fig = px.scatter之后添加趋势线？

当前代码：

def control_chart_by_compound(
                  df, 
                  x_column_name, 
                  y_column_name, 
                  trendline = False, 
                  trendlinetype = "ols", 
                  trendline_scope="overall", 
                 ):
    
    def _trendlinescatter():
        try: 
            assert trendlinetype == "ols", "Only Ordinary Least Squares (trendlinetype = 'ols') is currently supported."
            fig = px.scatter(x=x_column_name, 
                             y=y_column_name, 
                             labels={
                                 "x": x_column_name,
                                 "y": y_column_name,
                                 color_column_name: "Compounds"
                             },
                             trendline = trendlinetype, 
                             trendline_scope = trendline_scope, 
                            )
            return fig
        
        except Exception as e:
            err = "Unfortunately I'm unable to create a scatter plot with trendline from columns '{}' and '{}'. (ERROR: {})".format(x_column_name, y_column_name, e) 
            print(err)
            return _notrendlinescatter()
            
    def _notrendlinescatter():
        fig = px.scatter(df, 
                         x=x_column_name, 
                         y=y_column_name, 
                         labels={
                             "x": x_column_name,
                             "y": y_column_name,
                             color_column_name: "Compounds"
                         },
                        )
        return fig
                
    if trendline != False: 
        fig = _trendlinescatter()
    else:
        fig = _notrendlinescatter()

Answer 1

我有一个解决方法来解决这个问题，即添加trendline，然后在默认情况下隐藏它，让用户显示它。尝试更改withTrendline的值

import plotly.express as px

withTrendline = False # value comes from the callback 

df = px.data.tips()
fig = px.scatter(df, x="total_bill", y="tip", trendline="ols")
fig.update_traces(visible=withTrendline, selector=dict(mode="lines")) 
fig.show()