fitbitViz (version 1.0.7)

extend_AOI_buffer: Extract the sf-object and raster extent based on a buffer (in meters)

Description

Extract the sf-object and raster extent based on a buffer (in meters)

Usage

extend_AOI_buffer(
  dat_gps_tcx,
  buffer_in_meters = 1000,
  CRS = 4326,
  verbose = FALSE
)

Value

an object of class list

Arguments

dat_gps_tcx

this parameter corresponds to the output data.table of the 'GPS_TCX_data()' function

buffer_in_meters

an integer value specifying the buffer in meters. The bounding box of the input coordinates (longitudes, latitudes) will be extended by that many meters. The default value is 1000 meters.

CRS

an integer specifying the Coordinates Reference System. The recommended value for this data is 4326 (which is also the default value)

verbose

a boolean. If TRUE then information will be printed out in the console

Details

To create the buffer in meters using the 'sf' package I had to transform to another projection - by default I've used 7801 - as suggested in the following stackoverflow thread, https://stackoverflow.com/a/54754935/8302386

Examples

if (FALSE) {

require(fitbitViz)

#............................
# first extract the log-id(s)
#............................

USER_ID = '99xxxx'
token = 'my_long_web_api_token'

log_id = extract_LOG_ID(user_id = USER_ID,
                        token = token,
                        after_Date = '2021-03-13',
                        limit = 10,
                        sort = 'asc',
                        verbose = TRUE)
str(log_id)

#...................................
# then return the gps-ctx data.table
#...................................

res_tcx = GPS_TCX_data(log_id = log_id,
                       user_id = USER_ID,
                       token = token,
                       time_zone = 'Europe/Athens',
                       verbose = TRUE)
str(res_tcx)

#....................................................
# then compute the sf-object buffer and raster-extend
#....................................................

sf_rst_ext = extend_AOI_buffer(dat_gps_tcx = res_tcx,
                               buffer_in_meters = 1000,
                               CRS = 4326,
                               verbose = TRUE)
sf_rst_ext

}