Custom angular range in Scatterpolar

plotly.js
1

Hi there,
I recently moved from the deprecated polar chart go.Scatter to go.Scatterpolar. In the deprecated version, there was a very useful possibility of setting the angular axis according to a given range:
angularaxis=dict( range = [0,24] )
I did not manage to make this work in the new version. It seems that we can personalize ticks using categories, but then then the angular scale becomes discrete… which I do not wish.
Is there a possibility to have a custom continuous scale for Scatterpolar, like in the previous version? A concrete example would be to represents data happening in the time of a day, with an angular scale going from 0h to 24h. More simply, maybe it would be useful to add “hours” as possible thetaunits in addition to “radians”, “degrees” and “gradients”.
Thanks :slight_smile:

2

Really?!? The old polar renderer could do that? Oops, we weren’t aware of it while developing its replacement. Our apologies.

Sounds like you’re after a type: date angular axis with a set period of 24 hours. This is one of the most important open item listed in https://github.com/plotly/plotly.js/issues/2255.

3

Yes, that was possible, and a super cool feature actually :slight_smile:
Thanks for the update! I guess I’ll wait for the implementation of a type: date then.

4

Can you share an example of your old graph, to help us implement something similar for scatterpolar?

5

Sure, here’s a very simplified version of the piece of Dash code I used to run:

import dash
import flask
import plotly
import plotly.graph_objs as go
import dash_html_components as html
import dash_core_components as dcc

server = flask.Flask(__name__)
app = dash.Dash(__name__, server=server)

data_traces = []
for i in range(1,5):
    data_traces += [  go.Scatter( r = [i], t = [24/i],  mode='markers',  name='x = ' + str(i), marker=dict( size=i*100) )  ]

layout = go.Layout( title='Coucou',  font=dict( size=15, color = 'grey' ), plot_bgcolor='rgb(223, 223, 223)',angularaxis=dict( tickcolor='rgb(253,253,253)', range = [0,24]  ),
                    radialaxis=dict( range =[ 0,  5  ]  ), direction  = "counterclockwise", showlegend = True  )


app.layout = html.Div(children = [ dcc.Graph(id='graph-polar',style={ 'width' : '100%' }, figure = {'data': data_traces, 'layout': layout} ) ],
                        style={'width': '80%', 'fontFamily': 'Sans-Serif',  'margin-left': 'auto','margin-right': 'auto' }
                    )


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

Thanks :slight_smile:

1 Like
6

Sorry to revive this old topic, but any update on this issue? I would still need to use hours instead of radians on a polar chart. Alternatively, setting the ticks labels myself would also work, but this doesn’t seem possible either…