How to combine a heatmap and contour plot with Plotly Python

Question

I have two different plots, one heatmap and a contour plot, and I would like to put the contour on top of the heatmap. The z-value for each of the plots correspond to different quantities.

import plotly.graph_objects as go

fig1=go.Figure(go.Heatmap(
    x=data.X,
    y=data.Y,
    z=data0.Z1, zsmooth='best',
    colorscale='Viridis'
), layout=layout)

fig2=go.Figure(go.Contour(
    x=data.X,
    y=data.Y,
    z=round(data.Z2,3),
    zmin=0,
    zmax=0.3,
    contours_coloring='lines',
    line_width=2,
    colorscale=[[0,'blue'],[0.5,'black'],[1,'red']],
    contours=dict(
        start=0, end=0.01, size=1)
), layout=layout)

In Altair I could just use fig1 + fig2 but that does not work with Plotly. Unfortunately Altair does not have any contour capabilities. If this is not possible with Plotly, could this be achieved with matplotlib?

Edit: here is a data example

ls = [[-0.1,-3.0,-0.5,0.0],[-0.1,-2.0,-0.25,0.2],[-0.1,-1.0,-0.15,0.25],[-0.1,0.0,0,0.3],[-0.1,1.0,0.1,0.25],[-0.1,2.0,0.25,0.2],[-0.1,3.0,0.5,0.0],[0.0,-3.0,-0.5,0.0],[0.0,-2.0,-0.25,0.1],[0.0,-1.0,-0.15,0.11],[0.0,0.0,0.0,0.1],[0.0,1.0,0.1,0.0],[0.0,2.0,0.25,0.0],[0.0,3.0,0.5,0.0],[0.1,-3.0,-0.5,0.0],[0.1,-2.0,-0.5,0.12],[0.1,-1.0,-0.15,0.12],[0.1,0.0,0.0,0.13],[0.1,1.0,0.1,0.12],[0.1,2.0,0.5,0.12],[0.1,3.0,0.5,0.0]]

data = pd.DataFrame(ls, columns=['X', 'Y', 'Z1', 'Z2'])

what do you mean by contours_coloring='lines', also could you provide a sample of the dataset in order to check if my proposition would work? If you could provide details of the environment you're working on I may also be able provide some plotly advice — vlizana
– vlizana, Commented Feb 29, 2020 at 20:37
@vlizana contours_coloring='lines' allows to show colored lines on an empty background, i.e. without the underlying heatmap. You make look at the documentation to see an example: contour lines . I will edit my post later today to provide you with some of the data. I didn't put any because I didn't think it was relevant in this case. — Karim
– Karim, Commented Mar 2, 2020 at 13:31

Iker · Accepted Answer · 2020-05-10 17:08:05Z

2

Given your example, to put the contour on top the heat map you need to do:

fig1.add_trace(fig2.data[0])

answered May 10, 2020 at 17:08

Iker

831 silver badge9 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Sol Warsop · Accepted Answer · 2024-10-16 06:17:19Z

1

I believe that the desired result could be achieved using a single go.Countour plot. Simply set the key word argument contours_coloring="heatmap" for smooth colours behind the contour lines.

See https://plotly.com/python/contour-plots/#smooth-contour-coloring.

answered Oct 16, 2024 at 6:17

Sol Warsop

111 bronze badge

Collectives™ on Stack Overflow

How to combine a heatmap and contour plot with Plotly Python

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related