# Strange behavior during data updating **URL:** \ **Category:** 📊 Plotly Python\ **Created:** [June 2, 2020, 7:14am UTC](https://community.plotly.com/t/strange-behavior-during-data-updating/40429 "2020-06-02T07:14:59Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![manius.cezar](https://avatars.discourse-cdn.com/v4/letter/m/eada6e/32.png) [@manius.cezar](https://community.plotly.com/u/manius.cezar)\ **Post date:** [June 2, 2020, 7:14am UTC](https://community.plotly.com/t/strange-behavior-during-data-updating/40429/1 "2020-06-02T07:14:59Z")
Hi, I’m having some wired behavior during updating data to one of my graphs. This plot is dynamically updated - and data are being extended okay, without any issues. The problem appears when I want to update the layout of the graph (for example change Y axes range) and after layout update, it looks like on this gif. After I delete and recreate the plot, everything looks perfect until I change layout properties. Also, I don’t get any errors or exceptions. Did anyone also face this issue? ![plot2](https://us1.discourse-cdn.com/flex024/uploads/plot/original/2X/6/6fe097a08361b4d37c54045e2942a295c7f2ac4f.gif) ---
**Author:** ![empet](https://avatars.discourse-cdn.com/v4/letter/e/977dab/32.png) [@empet](https://community.plotly.com/u/empet)\ **Post date:** [June 2, 2020, 9:29pm UTC](https://community.plotly.com/t/strange-behavior-during-data-updating/40429/2 "2020-06-02T21:29:30Z")
Hi @manius.cezar, Without code it is impossible to express an opinion on your issue ☹ ---
**Author:** ![manius.cezar](https://avatars.discourse-cdn.com/v4/letter/m/eada6e/32.png) [@manius.cezar](https://community.plotly.com/u/manius.cezar)\ **Post date:** [June 24, 2020, 12:02pm UTC](https://community.plotly.com/t/strange-behavior-during-data-updating/40429/3 "2020-06-24T12:02:42Z")
Hi @empet, Sorry for a long time without an answer, but after some time I solved it myself. Anyway, the issue turned out to be `animate` property of `dcc.Grpah` object. To duplicate it, please run below code snippet. Run it with the `animate` option enabled and disabled (line #124). When it will be set to True, you will be able to see the issue. Below you can find the code snippet with a data.csv file for storing the data. data.csv: ```auto timestamp,value 2020-06-24 13:49:58.930175,0.6804218634026458 ``` Dash app: ```auto import dash from dash.dependencies import Input, Output, State, MATCH import dash_html_components as html import dash_core_components as dcc import plotly.graph_objects as go import random from dash.exceptions import PreventUpdate import pandas as pd import datetime import csv, json app = dash.Dash( __name__ ) app.layout = html.Div([ html.Div([ html.H3('Extend trace'), html.Button('Add graph', id='add_graph'), html.Div(id='graph_section'), ]), dcc.Interval( id='generator', interval=1000, n_intervals=0), html.Div( id='hidden_div', hidden=True ) ]) @app.callback( Output('hidden_div', 'children'), [Input('generator', 'n_intervals')] ) def gen_data(n_intervals): with open('data.csv', 'a', newline='') as csv_file: writer = csv.DictWriter(csv_file, ['timestamp', 'value']) writer.writerow({'timestamp': str(datetime.datetime.now()), 'value': random.random()}) return 'anything' @app.callback( Output('graph_section', 'children'), [Input('add_graph', 'n_clicks')] ) def add_graph(click): if click is None: raise PreventUpdate else: df = read_csv() data = [ go.Scatter( x=df['timestamp'], y=df['value'], mode='lines', name='some name', line={'color': '#FF0000'}, text='some text' ) ] data.append( go.Scatter( x=df['timestamp'], y=df['value'] * (-1), mode='lines', name='some name', line={'color': '#00FF00'}, text='some text' ) ) children = [] for i in range(click): div = html.Div( [ dcc.Graph( id={'index': i, 'type': 'graph'}, figure=dict( data=data, layout={ 'yaxis': { 'title': {'text': 'some titile'}, 'range': [-1,1], 'autorange': False }, 'xaxis': { 'title': {'text': 'Time (& date) [hh:mm:SS Month Day, Year]'}, 'autorange': True, 'rangemode': 'normal', 'rangeselector': { 'buttons': [ dict( count=10, label=' 10 seconds ', step='second', stepmode='backward' ), dict( count=1, label=' 1 minute ', step='minute', stepmode='backward' ), dict( count=10, label=' 10 minutes ', step='minute', stepmode='backward' ) ] }, 'rangeslider': { 'visible': True, 'yaxis': { 'rangemode': 'auto' } }, 'type':'date' }, 'showlegend': True } ), animate=True ), dcc.Interval( id={'index': i, 'type': 'interval'}, interval=1000, n_intervals=0), dcc.Input(id={'index': i, 'type': 'input'}, type='number', placeholder='Set graph scale', value=1, min=1, step=1, max=10) ] ) children.append(div) return children def read_csv(from_date: datetime.datetime = None): if from_date is None: return pd.read_csv('data.csv') else: df = pd.read_csv('data.csv') return df[df['timestamp'] > from_date] @app.callback( Output({'index': MATCH, 'type': 'graph'}, 'extendData'), [Input({'index': MATCH, 'type': 'interval'}, 'n_intervals')], [State({'index': MATCH, 'type': 'graph'}, 'figure')] ) def update_extend_traces_traceselect(n_intervals, existing): if n_intervals is None: raise PreventUpdate old_x = existing['data'][0]['x'] old_data = {'timestamp': old_x} old_df = pd.DataFrame(old_data) last_update_timestamp = old_df.iloc[-1]['timestamp'] new_df = read_csv(last_update_timestamp) if new_df is None: raise PreventUpdate data = dict( x = [new_df['timestamp'].to_list(), new_df['timestamp'].to_list()], y = [new_df['value'].to_list(), (new_df['value'] * (-1)).to_list()] ) return [data, [0, 1]] @app.callback( Output({'index': MATCH, 'type': 'graph'}, 'figure'), [Input({'index': MATCH, 'type': 'input'}, 'value')], [State({'index': MATCH, 'type': 'graph'}, 'figure')] ) def change_y_max_range(value, figure): if value is None: raise PreventUpdate else: print(figure['layout']) figure['layout']['yaxis']['range'] = [-value, value] return figure if __name__ == ' __main__': app.run_server(debug=True) ``` Please let me know if you can also duplicate this. Do you think it is a plotly bug, or I used this option incorrectly? Thanks!