Get the order of the categorical horizons for plotting
Arguments
- df
a dataframe containing the column name horizon which will
contain character strings indicating the horizon (by week, nowcast period,
or overall) of the score/quantile/sample.
Value
a dataframe containing the same columns as df with the horizon
column now an ordered factor with ordered levels as follows:
"overall", "calibration", "nowcast", "1 wk", "2 wks", "3 wks", "4 wks"