| das_read {swfscDAS} | R Documentation |
Read DAS file(s)
Description
Read one or more fixed-width DAS text file(s) generated by WinCruz into a data frame, where each line is data for a specific event
Usage
das_read(file, skip = 0, ...)
Arguments
file |
filename(s) of one or more DAS files |
skip |
integer; see |
... |
ignored |
Details
Reads/parses DAS data into columns of a data frame.
If file contains multiple filenames, then the individual
data frames will be concatenated.
The provided DAS file must adhere to the following column number and format specifications:
| Item | Columns | Format |
| Event number | 1-3 | |
| Event | 4 | |
| Effort dot | 5 | |
| Time | 6-11 | HHMMSS or HHMM |
| Date | 13-18 | MMDDYY |
| Latitude | 20-28 | NDD:MM.MM |
| Longitude | 30-39 | WDDD:MM.MM |
| Data1 | 40-44 | |
| Data2 | 45-49 | |
| Data3 | 50-54 | |
| Data4 | 55-59 | |
| Data5 | 60-64 | |
| Data6 | 65-69 | |
| Data7 | 70-74 | |
| Data8 | 75-79 | |
| Data9 | 80-84 | |
| Data10 | 85-89 | |
| Data11 | 90-94 | |
| Data12 | 95+ | |
See das_format_pdf for more information about DAS format requirements, and
note that 'Data#' columns may be referred to as 'Field#' columns in other documentation.
Value
A das_dfr object, which is also a data frame, with DAS data read into columns.
The data are read into the data frame as characters as described in 'Details',
with the following exceptions:
| Name | Class | Details |
| EffortDot | logical | TRUE if "." was present, and FALSE otherwise |
| DateTime | POSIXct | combination of 'Date' and 'Time' columns |
| Lat | numeric | 'Latitude' column converted to decimal degrees in range [-90, 90] |
| Lon | numeric | 'Longitude' column converted to decimal degrees in range [-180, 180] |
| Data# | character | leading/trailing whitespace trimmed for non-comment events (i.e. where 'Event' is not "C") |
| EventNum | character | leading/trailing whitespace trimmed; left as character for some project-specific codes |
| file_das | character | base filename, extracted from the file argument |
| line_num | integer | line number of each data row |
DateTime values have a (meaningless) time zone value of "UTC".
See the OffsetGMT column from das_process
for relevant time zone information
Warnings are printed if any unexpected events have NA DateTime/Lat/Lon values,
or if any Lat/Lon values cannot be converted to numeric values.
Events that are 'expected' to have NA DateTime/Lat/Lon values are:
C, ?, 1, 2, 3, 4, 5, 6, 7, 8
Examples
y <- system.file("das_sample.das", package = "swfscDAS")
das_read(y)