Get and set column names of Trackframe Key columns

Key columns meaning: easting, northing, time, and (opt) id column All 3-4 key column names can be accessed or set with tf_colnames(). Each also has a dedicated functions to access or set the names of the key columns. Setting column names in this way will rename the currently configured key column in the trackframe. It does not change the values of the column.

Usage

time_col(tf)

time_col(tf) <- value

id_col(tf)

id_col(tf) <- value

easting_col(tf)

easting_col(tf) <- value

northing_col(tf)

northing_col(tf) <- value

tf_colnames(tf)

tf_colnames(tf) <- value

Arguments

tf

a trackframe

value

new column naems. tf_colnames takes a named character vector with names easting, northing, time, and (opt) id. X_col() functions take a single string

Value

X_col returns a character object representing the column name. tf_colnames returns a named character vector of length 4 indicating the column names of each of the key columns.

Details

To identify a different (existing) column as a key column, use as.trackframe.

See also

tf_coords, as.trackframe, tf_id, tf_time

Examples

time_col(tf_mini)
#> [1] "time"
time_col(tf_mini) <- as.POSIXct(seq_along(nrow(tf_mini)))
colnames(tf_mini)
#> [1] "1"        "northing" "easting"  "id"      
id_col(tf_mini)
#> [1] "id"
id_col(tf_mini) <- "track_id"
colnames(tf_mini)
#> [1] "1"        "northing" "easting"  "track_id"
easting_col(tf_mini)
#> [1] "easting"
easting_col(tf_mini) <- "x"
northing_col(tf_mini)
#> [1] "northing"
northing_col(tf_mini) <- "y"
tf_colnames(tf_mini)
#>       time   northing    easting         id 
#>        "1"        "y"        "x" "track_id" 
tf_colnames(tf_mini)["id"] <- "track_id"