Unique values are extracted from the named column in a data frame. In the
case of a harp_list, unique values across all of the data frames
in the list are extracted as a single vector. If a column is not found,
a warning is issued and NULL is returned.
Usage
unique_col(.data, col)
unique_stations(.data)
unique_valid_dttm(.data)
unique_fcst_dttm(.data)Arguments
- .data
A data frame or harp_list
- col
The column from which to extract the unique values. Can be quoted or unquoted.
Details
unique_stations, unique_fcst_dttm and unique_valid_dttm
are wrappers around unique_col that extract the unique stations,
valid date-time and forecast start date-time using the standard harp
column names "SID", "valid_dttm" and "fcst_dttm" respectively.
Examples
unique_col(det_point_df, fcst_dttm)
#> [1] "2021-01-01 UTC"
unique_col(det_point_df, SID)
#> [1] 1001 1002
# Works with quoted column names too
unique_col(det_point_df, "SID")
#> [1] 1001 1002
# Use {{<var>}} for variables as columns
my_col <- "SID"
unique_col(det_point_df, {{my_col}})
#> [1] 1001 1002