convert to and from amt class 'track_xy'

convert to and from amt class 'track_xy'

# S3 method for track_xy
as_sftrack(data, crs = attr(data, "crs_"), ...)

# S3 method for track_xy
as_sftraj(data, ...)

sftrack_to_track_xy(data, ...)

Arguments

data	the sftrack object
crs	a crs string from rgdal of the crs and projection information for the spatial data. Defaults to the one provided by data.
...	any arguments to be passed on to `amt::make_track()`. See the help file in `amt` for more details

Examples

library("amt")
#> 
#> Attaching package: ‘amt’
#> The following object is masked from ‘package:MASS’:
#> 
#>     select
#> The following object is masked from ‘package:sp’:
#> 
#>     bbox
#> The following object is masked from ‘package:stats’:
#> 
#>     filter
data(sh)

## Add timestamp column, remove duplicated timestamps, and add ID
#column:
sh$timestamp <- as.POSIXct(paste(sh$day,sh$time))
sh <- sh[!duplicated(sh$timestamp), ]
sh$id <- "Animal 1"

## Create the 'track_xyt' object:
tr1 <- make_track(sh, x_epsg31467, y_epsg31467, timestamp,
                  id = id
)
#> .t found, creating `track_xyt`.

head(as_sftrack(tr1, crs = "+init=epsg:31467"))
#> Warning: GDAL Message 1: +init=epsg:XXXX syntax is deprecated. It might return a CRS with a non-EPSG compliant axis order.
#> sftrack (*locations*) with 6 features and 3 fields
#> geometry:   "geometry" (XY, CRS: DHDN / 3-degree Gauss-Kruger zone 3)
#> timestamps: "sft_timestamp" (integer)
#> groupings:  "sft_group" (*id*)
#> -------------------------------
#>         sft_timestamp      sft_group                geometry
#> 1 2008-03-30 00:01:47 (id: Animal 1) POINT (3558528 5999094)
#> 2 2008-03-30 06:00:54 (id: Animal 1) POINT (3558513 5999055)
#> 3 2008-03-30 12:01:47 (id: Animal 1) POINT (3558564 5999146)
#> 4 2008-03-30 18:01:24 (id: Animal 1) POINT (3558504 5999072)
#> 5 2008-03-30 18:25:56 (id: Animal 1) POINT (3558495 5999051)
#> 6 2008-03-30 18:26:05 (id: Animal 1) POINT (3558493 5999052)