Plotly Dash dcc.Interval 实时更新不工作（使用工作代码示例和数据）

Question

我正在尝试制作一个实时更新的 dash 应用程序，但实时更新仅在我手动按下网页上的刷新按钮时显示，直到那时图表没有更新，我正在尝试生成一个逐渐更新的热量从传感器读取的一些数据中绘制地图，以显示如果实时读取数据会是什么样子。

数据源位于：Data source used in code below 1MB in size only

import dash 
from dash.dependencies import Output, Input
import dash_core_components as dcc 
import dash_html_components as html 
import plotly 
import pandas as pd 
import random 
import plotly.graph_objs as go 




# The csv file for this dataset used here can be downloaded from:
#  https://easyupload.io/0ni29p (Hyperlinked in post as well)

cols = [  'shot' , 'chan' , 'peak_amplitude',  'onset_time_(ms)', 'bubble_period_(ms)']
cols_bubble_period  = [ 'shot' , 'chan' ,  'bubble_period_(ms)']
source_df = pd.read_csv('seq-4bubbleQC.txt').drop(['sequence', 'file'], axis=1)
source_df.columns = cols
source_df.loc[source_df['shot'] % 2 == 0, 'chan'] += 18

all_results =  pd.DataFrame(columns = cols)
i=0

def df_to_plotly(df):
    return {'z': df.values.tolist(),
            'x': df.columns.tolist(),
            'y': df.index.tolist()}


  
app = dash.Dash(__name__) 
  
app.layout = html.Div( 
    [ 
        dcc.Graph(id = 'live-graph', animate = True),
        html.Button('START_PLOT', id='plot_start',n_clicks=0),
        html.H2(id='hidden-div', style= {'display': 'none'} ),

        dcc.Interval( 
            id = 'graph-update', 
            interval = 5*1000, 
            n_intervals = 0
        ), 
    ] 
) 

@app.callback( 
    Output('hidden-div', 'children'), 
    [ Input('graph-update', 'n_intervals') ],
    [Input('plot_start', 'n_clicks')] 
) 

def update_frame(n_clicks, n_interval):
    global source_df 
    global i
    global all_results

    if n_clicks == 0:
        raise dash.exceptions.PreventUpdate()

    all_results = all_results.append((source_df[i: i+36]))
    i+=36
    #print(i)



@app.callback( 
    Output('live-graph', 'figure'), 
    [ Input('graph-update', 'n_intervals') ],
    [Input('plot_start', 'n_clicks')] 
) 
  
def update_graph_heat(n_clicks, n_interval): 

    global all_results
    

    all_results_1 = all_results.apply(pd.to_numeric)
    #all_results_1 = all_results_1.drop_duplicates()
    #all_results_1.to_csv('all_results.csv')
    df_s1 = all_results_1.loc[all_results_1['chan'] <=18]
    df_s1_bp = df_s1[cols_bubble_period]
    #print(df_s1_bp)
    #df_s1_bp.to_csv('test_data.csv')
    df_s1_pivoted = df_s1_bp.pivot(  'chan', 'shot', 'bubble_period_(ms)')
    
    data = go.Heatmap(df_to_plotly(df_s1_pivoted) ,  colorscale='rainbow', zmin=30.0, zmax=210.0)
    return {'data': [data], 
            'layout' : go.Layout(xaxis_nticks=20, yaxis_nticks=20)} 

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

图表仅在手动页面刷新完成时更新，如何使更新后的图表自动显示？

Answer 1

您的回调构造不正确。所有输入都应该在同一个列表中。你的第一个应该是这样的：

@app.callback( 
    Output('hidden-div', 'children'), 
    [Input('graph-update', 'n_intervals'),
     Input('plot_start', 'n_clicks')] 
) 
def update_frame(n_clicks, n_interval):
    global source_df...
    # etc.

Plotly Dash dcc.Interval 实时更新不工作（使用工作代码示例和数据）

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