get_boxes: Generating Bounding Boxes

In farinoushsharifi/TransGPS: Easy Analysis of GPS Data

Description

Generate a list of bounding boxes along the GPS recorded data

Usage

get_boxes(LatList, LongList, timeseq, resolution = 5, offLong = 0.001,
  offLat = 0.001)

Arguments

LatList	A vector of size n for latitudes collected from a GPS recording device
LongList	A vector of size n for longitudes collected from a GPS recording device
timeseq	A vector of size n for irregular time sequence of recorded GPS data in format "%Y-%m-%d %H:%M:%S"
resolution	(Optional) Approximate value of distance within each bounding box in kilometers
offLong	(Optional) A positive value of bounding box longitudal margin in decimal degrees
offLat	(Optional) A positive value of bounding box latitudal margin in decimal degrees

Value

get_boxes return a list of

• A matrix of size 4 X p of bounding boxes coordinates; with rows of ("left","bottom","right","top")

• A table of size n X 4 with columns of ("DateTime","Latitude","Longitude","boxcuts"); boxcuts column has p levels and shows the corresponding box for each coordinate

Examples

LatList <- c(31.67514,31.675195,31.67525,
31.675304,31.675356,31.675408,31.675467,
31.675517,31.675569,31.675623)

LongList <- c(-106.326522,-106.326367,
-106.326211,-106.326058,-106.325901,
-106.325739,-106.325572,-106.32541,
-106.325247,-106.325092)

timeseq <- c("2019-04-29 15:20:51",
"2019-04-29 15:21:03","2019-04-29 15:21:06",
"2019-04-29 15:21:15","2019-04-29 15:21:17",
"2019-04-29 15:21:32","2019-04-29 15:21:34",
"2019-04-29 15:21:51","2019-04-29 15:22:09",
"2019-04-29 15:22:36")

timeseq <- as.POSIXct(timeseq)

offLong=0.001
offLat=0.002

#generates only one box and gives warning for the high resolution
get_boxes(LatList, LongList, timeseq, resolution=1000,offLong,offLat)

#generates only one box and gives warning for the small resolution
get_boxes(LatList, LongList, timeseq, resolution=0.001,offLong,offLat)

#generates two bounding boxes
get_boxes(LatList, LongList, timeseq, resolution=0.1,offLong,offLat)

farinoushsharifi/TransGPS documentation built on June 3, 2019, 7:19 a.m.