Hi, how can I make a real-time live update graph with multiple traces in it?
For every time interval, i need to read line from “tmp.txt” to data[‘prof’] and data [‘pred’] and update in the line graph.
I found the solution for live-updating here (https://pythonprogramming.net/live-graphs-data-visualization-application-dash-python-tutorial/) but it does not show how to @app.callback for multiple traces. Also I found out that it uses “Event” which is outdated.
My coding is as follow, appreciate if someone can help me. Thanks.
import dash
import dash_daq as daq
import dash_core_components as dcc
import dash_html_components as html
from dash.dependencies import Input, Output
from collections import deque
#class dashboard():
def read():
with open ("tmp.txt", "r") as f:
for line in f:
data=line.split(',')
return data
i=0
data = { 'prof':deque(maxlen=120), 'pred': deque(maxlen=120) }
external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css']
app = dash.Dash(__name__, external_stylesheets=external_stylesheets)
app.layout = html.Div(
children=[
dcc.Interval(id='timer', interval=1000),
html.Br(),
html.Div([
dcc.Graph(id='graph')
])
]
)
@app.callback(Output('graph','figure'), [Input('timer','n_intervals')])
def update_graph():
data=read()
X.append(i)
data['prof'].append(float(data[1]))
data['pred'].append(float(data[2]))
''' what to do here....'''
.........
Edit 1: I try to call back like this but it does not work
@app.callback(Output('graph','figure'), [Input('timer','n_intervals')])
def update_graph():
data=read()
X.append(i)
data['prof'].append(float(data[1]))
data['pred'].append(float(data[2]))
figure={
'data':[
{'x':X,'y':CPU['prof'],'type':'scatter','name':'Profiled'},
{'x':X,'y':CPU['pred'],'type':'scatter','name':'Predicted'}
]
}
i+=1
return figure