tickmode="array" with custom tickvals ticktext doesn't work at all

From plotly doc:

Example:

import pandas as pd
import numpy as np

np.random.seed(42)
feature = pd.DataFrame({'ds': pd.date_range('20200101', periods=100*24, freq='H'), 
                        'y': np.random.randint(0,20, 100*24) , 
                        'yhat': np.random.randint(0,20, 100*24) , 
                        'price': np.random.choice([6600, 7000, 5500, 7800], 100*24)})


import plotly.graph_objects as go
import plotly.offline as py
import plotly.express as px
from plotly.offline import init_notebook_mode

init_notebook_mode(connected=True)


y = feature.set_index('ds').resample('D')['y'].sum()

fig = go.Figure()
fig.add_trace(go.Scatter(x=y.index, y=y))


x_dates = y.index.to_series().dt.strftime('%Y-%m-%d').sort_values().unique()


layout = dict(
    xaxis=dict(
        tickmode="array",
        tickvals=np.arange(0, x_dates.shape[0],2).astype(int),
        ticktext=x_dates[::2],
        tickformat='%Y-%m-%d',
        tickangle=45,
    )
)

fig.update_layout(layout)
fig.show()

Result:

Since length of x_dates[::2] is 50 , the ticknumber doesn’t match at all . How do I sovle it ??

[eromoe]

OK, I put full example here :

I like to see

import pandas as pd
import numpy as np

np.random.seed(42)
feature = pd.DataFrame({'ds': pd.date_range('20200101', periods=100*24, freq='H'), 
                        'y': np.random.randint(0,20, 100*24) , 
                        'yhat': np.random.randint(0,20, 100*24) , 
                        'price': np.random.choice([6600, 7000, 5500, 7800], 100*24)})


import plotly.graph_objects as go
import plotly.offline as py
import plotly.express as px
from plotly.offline import init_notebook_mode

init_notebook_mode(connected=True)


y = feature.set_index('ds').resample('D')['y'].sum()

fig = go.Figure()

x_dates = y.index.to_series().dt.strftime('%Y-%m-%d').sort_values().unique()
fig.add_trace(go.Scatter(x=x_dates, y=y))

layout = dict(
    xaxis=dict(
        tickmode="auto",
        nticks=50,
        tickformat='%Y-%m-%d',
        tickangle=45,
    )
)

fig.update_layout(layout)
fig.show()

---

tickmode=“auto” and nticks=50 is fine for me .

I am here just want to report this problem , because plotly is very handy now, I hope it would be bettter

1. x string, tickvals string , ticktext string , doesn’t show 50 xticks :

import pandas as pd
import numpy as np

np.random.seed(42)
feature = pd.DataFrame({'ds': pd.date_range('20200101', periods=100*24, freq='H'), 
                        'y': np.random.randint(0,20, 100*24) , 
                        'yhat': np.random.randint(0,20, 100*24) , 
                        'price': np.random.choice([6600, 7000, 5500, 7800], 100*24)})


import plotly.graph_objects as go
import plotly.offline as py
import plotly.express as px
from plotly.offline import init_notebook_mode

init_notebook_mode(connected=True)


y = feature.set_index('ds').resample('D')['y'].sum()

fig = go.Figure()

x_dates = y.index.to_series().dt.strftime('%Y-%m-%d').sort_values().unique()
fig.add_trace(go.Scatter(x=x_dates, y=y))    # x is string

layout = dict(
    xaxis=dict(
        tickmode="array",
        tickvals=x_dates[::2],    # string
        ticktext=x_dates[::2],    # string 
        tickformat='%Y-%m-%d',
        tickangle=45,
    )
)

fig.update_layout(layout)
fig.show()

results with wrong xticks :

2 . x date , tickvals date ticktext string

import pandas as pd
import numpy as np

np.random.seed(42)
feature = pd.DataFrame({'ds': pd.date_range('20200101', periods=100*24, freq='H'), 
                        'y': np.random.randint(0,20, 100*24) , 
                        'yhat': np.random.randint(0,20, 100*24) , 
                        'price': np.random.choice([6600, 7000, 5500, 7800], 100*24)})


import plotly.graph_objects as go
import plotly.offline as py
import plotly.express as px
from plotly.offline import init_notebook_mode

init_notebook_mode(connected=True)


y = feature.set_index('ds').resample('D')['y'].sum()

fig = go.Figure()

x_dates = y.index.to_series().dt.strftime('%Y-%m-%d').sort_values().unique()
fig.add_trace(go.Scatter(x=y.index, y=y))   # x is date

layout = dict(
    xaxis=dict(
        tickmode="array",
        tickvals=y.index[::2],   #  date
        ticktext=x_dates[::2],    # string
        tickformat='%Y-%m-%d',
        tickangle=45,
    )
)

fig.update_layout(layout)
fig.show()

still wrong result

[nicolaskruchten]

Ah, OK, the problem is that you’re not seeing as many tick labels as you would expect, got it.

There does seem to be a bug here, which I’ll investigate, because while I get the expected output with:

import plotly.graph_objects as go

fig = go.Figure()
fig.add_trace(go.Scatter(x=["2010-01-01", "2010-02-01", "2010-03-01"], y=[1,3,2]))
fig.update_xaxes(tickvals=["2010-01-15", "2010-02-15"], ticktext=["A","B"])
fig.show()

If I then manually set tickmode="array" I see the default ticks, even though setting tickvals internally is meant to set tickmode="array" !