How to resize legend items

📊 Plotly Python
1

Hi there,

Is there anything that can be done to resize the items (specifically the ID color boxes, not the font) displayed in my legend when creating a figure? When I try to export images at high resolutions, the legend winds up being much too small.

Realize I posted a similar question pertaining to choropleth figures the other day, but I’d be happy with even a generalist solution.

Thanks!

1 Like
2

You could use the layout attributes itemsizing and itemwidth:

import plotly.graph_objects as go

dict_of_fig = dict({
    "data": [{"type": "scatter",
              "x": [1, 2, 3],
              "y": [1, 3, 2]}],
    "layout": {"legend": {"itemsizing": "constant", "itemwidth": 100}}
})

fig = go.Figure(dict_of_fig)
fig.add_trace(go.Scatter(x=[1, 2, 3], y=[2, 3, 4]))
fig.show()

image
image1093×425 16.6 KB

3

Hmmm, it seems the issue is that when the legend items are squares (rather than lines), width simply adds a bunch of white space on either side. Is there anything to enlarge?

4

Unfortunately there is no attribute to change the item height independently of the trace. Also see this related thread:

5

Interesting! I’m hoping that because I’m working with choropleths, marker size may not affect the actual chart but still affect the legend. Thanks for your help!

6

+1 Would be great if legends could be increased/decreased in size independently of the rest of the figure. I am currently exporting a PDF and then change the legend size with Adobe Illustrator.

I have not tried though > r - Change legend size in plotly chart - Stack Overflow

7

No, only font size, e.g.

import plotly.express as px

df = px.data.iris()
fig = px.scatter(df, x="sepal_length", y="sepal_width", color="species",
                title="Playing with Fonts")

fig.update_layout(legend = dict(font = dict(family = "Courier", size = 50, color = "black")),
                  legend_title = dict(font = dict(family = "Courier", size = 40, color = "blue")))
fig.show()

newplot-40
newplot-40972×525 30.4 KB

8

Yeah, I find it very frustrating that there is no way to adjust legend size without changing the trace size (which I’ve found can’t be done with choropleths angways). I suppose it’s not a huge problem when working with svgs, but Mapbox choropleths in particular don’t appear to vectorize properly so scaling creates a blurry mess. Hopefully that functionality comes at some point.

9

Is there a feature request regarding this on GitHub already?

10

Frustrating indeed, in my case I have a bubble charts where the bubble area is defined by a column of my dataframe.
And I get the same kind of result as @windrose.

My audience is >50 y.o, they keep asking for larger symbols and legends…

11

I dont know if it will help, I have a similar problem and it didn’t help either.

  • overwrite (bool) – If True, existing properties will be overwritten. If False, recursively apply updates to existing properties, retaining properties that are not specified in the update operation.
12

Here a related GitHub issue can be found.

13

sorry, I am lost… I did that and it doesn’t work, I am no very nice in coding… i read the github and I don’t understand the solution…
The legend item are too little, my code is that …

Update layout with adjusted legend item width

fig.update_layout(
plot_bgcolor=‘#F8F0EB’,
width=3508,
height=2480,
font=dict(
size=50 # Adjust the font size as needed
),
legend=dict(
font=dict(size=50), # Adjust the legend font size as needed
itemsizing=‘trace’, # Maintain constant legend item size
)
)