Force show text on Nan Heatmap cells

📊 Plotly Python
1

Hi everyone, I’m making calendar heatmap and have next issue:

When some days don’t have z-values, I fill them with None. In this case, text over cells with z=None wouldn’t have text applied (day number)

newplot (5)
newplot (5)1904×895 24.1 KB

Replacing None with 0 does not solve issue, as it would break a color scale and return something like this:

newplot
newplot1904×895 23.4 KB

How can I force text to be shown on cells where z-value is None?

2

hi @ilazariev
:wave: welcome to the community.

This is an interesting problem. Can you share the full code with us so we can reproduce the error on our computer?

3

minimum example would be as follows:

import plotly.graph_objects as go

if __name__ == "__main__":
    z = [[None, None, 3], [3, 4, 3], [5, 6, None]]
    text = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
    heatmap = go.Heatmap(
        x=[0, 1, 2],
        y=[0, 1, 2],
        z=z,
        texttemplate="%{text}",
        text=text,
        coloraxis="coloraxis",
        showscale=True,
    )
    fig = go.Figure(heatmap)
    fig.show()

newplot (1)
newplot (1)1904×895 18.3 KB

as you can see, three cells are empty(where z-value equals to None) and thus, text is not shown.
What I want to achieve is just show text on such cells. Is it possible?

1 Like
4

Thanks for the MRE, @ilazariev . I’m talking to my colleagues to see if there is any way around displaying text when z values are None.

5

Hi @ilazariev
It looks like the text is there, it’s just white and very hard to see. Try to change the text color.
fig.update_traces(textfont_color='black').

Full code:

import plotly.graph_objects as go

z = [[None, None, 3], [3, 4, 3], [5, 6, None]]
text = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
heatmap = go.Heatmap(
    x=[0, 1, 2],
    y=[0, 1, 2],
    z=z,
    texttemplate="%{text}",
    text=text,
    coloraxis="coloraxis",
    showscale=True,
)
fig = go.Figure(heatmap)
fig.update_traces(textfont_color='black')
fig.show()
1 Like
6

thank you very much!