Roassal charts do not understand dates

[akevalion]

In the following example,

rawData := DataFrame 
    readFromCsv: (ZnClient new 
        get: 'https://github.com/openZH/covid_19/blob/master/COVID19_Fallzahlen_CH_total.csv?raw=true').

grison := rawData reject: [ :row | (row at: #abbreviation_canton_and_fl) ~= 'GR' ].
dates := (grison column: #date) collect: [ :date | date julianDayNumber ] as: Array.

...

chart := RSChart new.
chart add: (RSHorizontalTick new
    labelConversion: [ :number | Date julianDayNumber: number ];
    yourself).

If roassal understood dates (or magnitudes) then no conversion from the data frame to numbers, nor number to label should have been needed!

[akevalion]

Moved to roassal3