[BUG] imshow (Heatmap) unexpectedly cuts parts of the data?

[amiragha]

Environment information:

dash                               1.18.1
dash-core-components               1.3.1
dash-html-components               1.0.1
dash-renderer                      1.1.2
dash-table                         4.4.1

Here is the issue: the following basic example doesn't show all the 9 cells of the data:

import dash                                                                                                                                                   
import dash_core_components as dcc                                                                                                                            
import dash_html_components as html                                                                                                                           
import plotly.express as px                                                                                                                                   
import numpy  as np                                                                                                                                           
                                                                                                                                                              
fig = px.imshow(                                                                                                                                              
    np.random.random([3, 3]),                                                                                                                                 
    x=['1', '2', '3m'],                                                                                                                                       
    y=['1', '2', '3m'],                                                                                                                                       
)                                                                                                                                                             
                                                                                                                                                              
app = dash.Dash(__name__)                                                                                                                                     
                                                                                                                                                              
app.layout = html.Div([                                                                                                                                       
    html.P("Example"),                                                                                                                                        
    dcc.Graph(id="graph", figure=fig),                                                                                                                        
])                                                                                                                                                            
                                                                                                                                                              
app.run_server(debug=True) 

It only shows a single block/cell of color instead of 9 different random colors?! The issue is due to uncommon choice of labels x, y, if I remove the "m" or don't give x, y labels it works as expected.

[alexcjohnson]

Try upgrading plotly.py (pip install --upgrade plotly) - plotly/plotly.py#2951 (🙇 @nicolaskruchten) makes autotyping stricter so will give you category axes because the values you provided are strings. With plotly.py v4.13.0 I saw what you describe (though I confess I don't quite understand why it took one value on each axis and not two), but with v4.14.2 I see the desired output:

[gvwilson]

Hi - we are tidying up stale issues and PRs in Plotly's public repositories so that we can focus on things that are most important to our community. If this issue is still a concern, please add a comment letting us know what recent version of our software you've checked it with so that I can reopen it and add it to our backlog. (Please note that we will give priority to reports that include a short reproducible example.) If you'd like to submit a PR, we'd be happy to prioritize a review, and if it's a request for tech support, please post in our community forum. Thank you - @gvwilson