The airdas_dfr class is a subclass of data.frame,
created to provide a concise and robust way to ensure that the input
to airdas_processadheres to certain requirements.
Specifically, objects of class airdas_dfr are data frames with specific column names and classes,
as detailed in the 'Properties of airdas_dfr' section.
Objects of class airdas_dfr are created by
airdas_read or as_airdas_dfr,
and are intended to be passed directly to airdas_process.
Subsetting or otherwise altering an object of class airdas_dfr will cause
the object to drop its airdas_dfr class attribute, although note that combining
two airdas_dfr objects using rbind
will return an object with a airdas_dfr class attribute.
airdas_process will then try to coerce the object to a
airdas_dfr object. It is strongly recommended to pass an object of class airdas_dfr to
airdas_process before subsetting, e.g. for events from a certain date range.
Properties of airdas_dfr objects
Objects of class airdas_dfr have a class attribute of c("airdas_dfr", "data.frame").
They must have a column file_type where all values are one of:
"turtle", "caretta", "survey", or "phocoena"
(case sensitive; see airdas_read for more details).
airdas_dfr objects also must not have any NA event codes.
In addition, they must have the following column names and classes:
| Column name | Column class |
| Event | "character" |
| EffortDot | "logical" |
| DateTime | c("POSIXct", "POSIXt") |
| Lat | "numeric" |
| Lon | "numeric" |
| Data1 | "character" |
| Data2 | "character" |
| Data3 | "character" |
| Data4 | "character" |
| Data5 | "character" |
| Data6 | "character" |
| Data7 | "character" |
| EventNum | "character" |
| file_das | "character" |
| line_num | "integer" |
| file_type | "character" |