brownian.motion.variance.dyn: Calculates the dynamic brownian motion variance

Description Usage Arguments Value Author(s) References See Also Examples

Description

A function to calculate the dynamic brownian motion variance for a movement track. It can be also used by advanced programmers to program against.

Usage

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  ## S4 method for signature '.MoveTrackSingle,numeric,numeric,numeric'
brownian.motion.variance.dyn(object, location.error, window.size, margin)

Arguments

object

a move, moveStack or moveBurst object can be used for variance calculation. This object must be in a flat coordinate system (projection different to longitude/latitude), use spTransform to transform your coordinates.

location.error

single numeric value or vector of the length of coordinates that describes the error of the location (sender/receiver) system in map units.

window.size

The size of the moving window along the track for the variance calculation. Larger windows provide more stable/accurate estimates of the brownian motion variance but are less well able to capture more frequent changes in behavior.

margin

The margin size used for variance calculation.

Value

'dBMvariance' object, if move object is provided
'dBMvarianceStack' object, if moveStack object is provided
'dBMvarianceBurst' object, if moveBurst object is provided

Author(s)

Bart Kranstauber & Anne Scharf

References

Kranstauber, B., Kays, R., LaPoint, S. D., Wikelski, M. and Safi, K. (2012), A dynamic Brownian bridge movement model to estimate utilization distributions for heterogeneous animal movement. Journal of Animal Ecology. doi: 10.1111/j.1365-2656.2012.01955.x

See Also

brownian.bridge.dyn

Examples

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data(leroy)
data2 <- spTransform(leroy[1:80,], CRSobj="+proj=aeqd +ellps=WGS84", center=TRUE)
err<-rep(23.5,n.locs(data2))
dBMvar <- brownian.motion.variance.dyn(data2, location.error=err, margin=13, window.siz=31)
dBMvar

Example output

Loading required package: geosphere
Loading required package: sp
Loading required package: raster
Loading required package: rgdal
rgdal: version: 1.2-10, (SVN revision 673)
 Geospatial Data Abstraction Library extensions to R successfully loaded
 Loaded GDAL runtime: GDAL 1.10.1, released 2013/08/26
 Path to GDAL shared files: /usr/share/gdal/1.10
 Loaded PROJ.4 runtime: Rel. 4.8.0, 6 March 2012, [PJ_VERSION: 480]
 Path to PROJ.4 shared files: (autodetected)
WARNING: no proj_defs.dat in PROJ.4 shared files
 Linking to sp version: 1.2-3 
NOTE: rgdal::checkCRSArgs: no proj_defs.dat in PROJ.4 shared files
NOTE: rgdal::checkCRSArgs: no proj_defs.dat in PROJ.4 shared files
NOTE: rgdal::checkCRSArgs: no proj_defs.dat in PROJ.4 shared files
NOTE: rgdal::checkCRSArgs: no proj_defs.dat in PROJ.4 shared files
class       : dBMvariance 
features    : 80 
extent      : -2084.331, 2085.19, -1763.593, 1763.915  (xmin, xmax, ymin, ymax)
coord. ref. : +proj=aeqd +ellps=WGS84 +lon_0=-73.8734723 +lat_0=42.73388425 
variables   : 17
names       :           timestamp, eobs.battery.voltage, eobs.horizontal.accuracy.estimate, eobs.key.bin.checksum, eobs.speed.accuracy.estimate,    eobs.start.timestamp, eobs.status, eobs.temperature, eobs.type.of.fix, eobs.used.time.to.get.fix, ground.speed, heading, height.above.ellipsoid, utm.easting, utm.northing, ... 
min values  : 2009-02-11 12:16:45,                 3615,                              3.33,               7099154,                         2.39, 2009-02-11 12:14:59.000,           A,               15,                3,                         4,         0.02,    0.00,                   -5.3,    590119.2,      4730144, ... 
max values  : 2009-02-13 03:01:38,                 3666,                             66.56,            4219653549,                        21.32, 2009-02-13 03:00:01.000,           A,               35,                3,                       108,         7.64,  359.79,                  153.7,    594325.1,      4733640, ... 
timestamps  : 2009-02-11 12:16:45 ... 2009-02-13 03:01:38 Time difference of 2 days  (start ... end, duration) 
sensors     : gps 
indiv. data : eobs.fix.battery.voltage, manually.marked.outlier, visible, sensor.type, individual.taxon.canonical.name, tag.local.identifier, individual.local.identifier, study.name, study.timezone 
indiv. value: 0 NA true gps Martes pennanti 74 Leroy Urban fisher GPS tracking Eastern Standard Time 
unused rec. : 1071 
margin      : 13 
window size : 31 

move documentation built on Nov. 17, 2017, 8:07 a.m.