using month(date) togheter with mean(value) for multiple years

[dataagile-ema]

Hi!

In this example:
alt.Chart(temps).mark_bar().encode(
x='month(date):O',
y='mean(temp):Q'
)
If there are multiple years in the series ‘date’, the chart will show a mean for all the occurrences of the same month (june for example) from the different years included in ‘date’.
Is there a recommended way to get around this? I want a mean per month but separating june 2020 from june 2021.

Best Regards

[mattijn]

Use yearmonth() instead of month().

[dataagile-ema]

great, thanks!