i have dataframe, in which we are given x and y columns and between them i want to sketch regression model, main idea is that i should use dash framework, as according chow test , there could be difference between two regression model at different instance value,based on following link : dash models i wrote following code : import pandas as pd from dash import Dash,html,dcc,callback,Output,Input from sklearn.linear_model import LinearRegression import plotly.express as px data =pd.read_csv("regression.csv") model =LinearRegression() print(data) app = Dash() # Requires Dash 2.17.0 or later app.layout = [ html.H1(children='Our regression Model', style={'textAlign':'center'}), dcc.Dropdown(data.Year.unique(), '2004', id='dropdown-selection'), dcc.Graph(id='graph-content') ] @callback( Output('graph-content', 'figure'), Input('dropdown-selection', 'value') ) def scatter_graph(value): selected =data[data.Year==value] return px.scatter(selected,x='x',y='y') @callback( Output('graph-content', 'figure'), Input('dropdown-selection', 'value') ) def Regression_graph(value): selected =data[data.Year==value] X =selected['x'].values X =X.reshape(-1,1) y =selected['y'].values model.fit(X,y) y_predicted =model.predict(X) return px.line(selected,x='x',y=y_predicted) if __name__ =='__main__': app.run(debug=True) this part works fine : @callback( Output('graph-content', 'figure'), Input('dropdown-selection', 'value') ) def scatter_graph(value): selected =data[data.Year==value] return px.scatter(selected,x='x',y='y') but second decorator for regression plot does not work, here is example : please help me how to fix it? Continue reading...