The airdas_df class is a subclass of data.frame,
created to provide a concise and robust way to ensure that the input to
downstream AirDAS processing functions, such as airdas_sight,
adheres to certain requirements.
Specifically, objects of class airdas_df are data frames with specific column names and classes,
as detailed in the 'Properties of airdas_df' section.
In addition, airdas_df objects have no NA values
in the 'Lat' 'Lon', or 'DateTime' columns.
Objects of class airdas_df are created by airdas_process
or as_airdas_df, and are intended to be passed directly to
DAS processing functions such as airdas_sight.
Subsetting, say for a specific date or transect number,
or otherwise altering an object of class airdas_df
will cause the object to drop its airdas_df class attribute, although note
that combining two airdas_df objects using rbind
will return an object with a airdas_df class attribute.
If this object is then passed to a DAS processing function such as airdas_sight,
the function will try to coerce the object to a airdas_df object.
Properties of airdas_df objects
Objects of class airdas_df have a class attribute of c("airdas_df", "data.frame").
All values in the OnEffort column must be TRUE or FALSE (no NA values).
All on effort events must have non-NA Lat/Lon/DateTime values, and
there must be no events with a "#" event code (deleted event).
Like airdas_dfr events, there must be a file_type column where
all values are one of: "turtle", "caretta", "survey", or "phocoena"
(case sensitive; see airdas_read for more details about file types).
In addition, airdas_df objects must have the following column names and classes:
| Column name | Column class |
| Event | "character" |
| DateTime | c("POSIXct", "POSIXt") |
| Lat | "numeric" |
| Lon | "numeric" |
| OnEffort | "logical" |
| Trans | "character" |
| Bft | "numeric" |
| CCover | "numeric" |
| Jelly | "numeric" |
| HorizSun | "numeric" |
| VertSun | "numeric" |
| HKR | "character" |
| Haze | "logical" |
| Kelp | "logical" |
| Red tide | "logical" |
| AltFt | "numeric" |
| SpKnot | "numeric" |
| ObsL | "character" |
| ObsB | "character" |
| ObsR | "character" |
| Rec | "character" |
| VLI | "character" |
| VLO | "character" |
| VB | "character" |
| VRI | "character" |
| VRO | "character" |
| Data1 | "character" |
| Data2 | "character" |
| Data3 | "character" |
| Data4 | "character" |
| Data5 | "character" |
| Data6 | "character" |
| Data7 | "character" |
| EffortDot | "logical" |
| EventNum | "character" |
| file_das | "character" |
| line_num | "integer" |
| file_type | "character" |