Horizontal Color bar for plotly subplots

Hi there

I’ve been having some trouble switching the color bar on a subplot (of graphobject.scatter objects) from vertical to horizontal.

I’ve tried fig.update_coloraxes(colorbar_orientation = “h”) , fig.update_layout(coloraxis= dict(orientation = ‘h’)) and a few others but nothing seems to work.

I also came across this post https://github.com/plotly/plotly.js/issues/1244 and was wondering if what I’m trying to do is even possible in plotly

any help is much appreciated

Hi @dashingpy ,

I am not sure if there is a diffenrence when updating sublots, but did you try this?

import plotly.graph_objects as go

data = go.Bar(y=[1,2,3], orientation='v')
fig = go.Figure(data=data)

Just tried it, unfortunately it didn’t work either

Strange, could you post your code (or an MRE) so that we can reproduce this behavior?

Hi thanks for your help, Here’s the code I’m using to create the subplots

   fig = make_subplots(rows=rows, cols=cols,
        if n:
            selectedData = None
            clickdata = None
            fig.data = []
            pastselectedData = pd.DataFrame()
        if clickdata is not None:
            x = clickdata['points'][0]['x']
            dfclick = dff[dff['TWS'] == x]
            if len(pastselectedData) == 0:
                pastselectedData = dfclick
                print('saved first time')
            if len(pastselectedData) >0:
                pastselectedData = pastselectedData.append(dfclick)
        row =1
        col = 1
        for attr in attributes:
            if col > 3:
                row += 1
                col = 1
            fig.add_trace(go.Scatter(x=dff['TWS'], y=dff[attr],mode='markers', name= attr,
                            marker=dict(color=dff[color], colorscale='Bluered',showscale=True),
                            marker_size = abs(dff[size]/2))#,customdata= [dff[attr]])
            if len(pastselectedData) >0:
                y = pastselectedData[attr].tolist()
                x = pastselectedData['TWS']
                fig.add_trace(go.Scatter(x=x, y=y,marker_size=10,mode='markers', marker_color="yellow",name= 
                    row=row, col=col)
            # if clickdata is not None:
            #     # print(clickdata)
            #     y = dfclick[attr].to_list()
            #     x = x
            #     fig.add_trace(go.Scatter(x=[x], y=y,marker_size=10, marker_color="yellow",name= f'{attr}',showlegend=False),
            #         row=row, col=col)
            if selectedData is not None:
                xlist =[]
                ylist =[]
                for point in selectedData['points']:
                dfclick = dff[dff['TWS'].isin(xlist)]
                y = dfclick[attr].to_list()
                x = xlist
                fig.add_trace(go.Scatter(x=x, y=y,marker_size=10,mode='markers', marker_color="yellow",name= 
                    row=row, col=col)
        fig.layout.coloraxis.colorbar.orientation = 'h'
        # print(fig.layout.coloraxis.colorbar.orientation)
        # fig.update_traces(colorbar_orientation='h')
        # fig.update_layout(coloraxis= dict(orientation = 'h'))
        # fig.update_coloraxes(colorbar_orientation = "h")

This text will be hidden

Hi @dashingpy ,

Oh man, I just realized that I misunderstood your question. I thought you had a bar plot and wanted to change the orientation of the bars from vertical to horizontal, sorry for that.

Try the following, at least in my example it creates a horizontal colorbar:

import plotly.express as px
from plotly.subplots import make_subplots

df = px.data.iris()

fig = make_subplots(rows=1,cols=2, shared_yaxes=True)

bar1 = px.scatter(df, x="sepal_width", y="sepal_length", color='petal_length')
bar2 = px.scatter(df, x="sepal_length", y="sepal_width", color='petal_length')

fig.add_traces(bar1.data, rows=1, cols=1)
fig.add_traces(bar2.data, rows=1, cols=2)

fig.update_coloraxes(colorbar={'orientation':'h', 'thickness':20, 'y': -1.0})

1 Like

Thanks for following up. Unfortunately still no luck. I think it might be because I’m using a plotly graph object scatter instead of a plotly express scatter.


try this:

fig.for_each_coloraxis(lambda x: x['colorbar'].update({'orientation':'h', 'thickness':20, 'y': -1.0}))

Yes, unfortunately you are right. I tried with go. Scatter() and my solution did not work anymore.

Hi @dashingpy ,

I think I figured it out:

import plotly.graph_objects as go
from plotly.subplots import make_subplots

# create base figure
fig = make_subplots(rows=1,cols=2, shared_yaxes=True)

# create traces using plotly.graph_objects
b1 = go.Scatter(x=[1,2,3], y=[1,2,3], mode='markers' ,marker={'color':[35,67,89], 'colorscale': 'Viridis','showscale':True})
b2 = go.Scatter(x=[5,2,6], y=[9,2,4], mode='markers' ,marker={'color':[22,5,111]})

# add traces to figure
fig.add_traces(b1, rows=1, cols=1)
fig.add_traces(b2, rows=1, cols=2)

# hide legend
fig.update_layout(showlegend = False)

which creates


fig.update_traces({'marker': {'colorbar': {'orientation': 'h', 'y': -1.0}, 'colorscale': 'Viridis'}})

changes to this:

Please tell me, this works for you :scream: :rofl:

1 Like

YES!!! you are my hero.

Thank you so much for saving the day, this was defeating me