GetVT {bcpa} | R Documentation |
The VT table containes speeds, steplengths, orientations
and other summaries derived from a track. The output of
this function is (typically) meant to feed the
WindowSweep
function.
GetVT(Data, units = "hour", skiplast = TRUE)
Data |
a track to analyze. Must contain columns: X,
Y and Time (as a POSIX object). The |
units |
the time units for the analysis; one of
|
skiplast |
filters away last step. |
a data frame with the following columns:
Z.start,
Z.end |
the start and end locations (as complex coordinates) |
S |
the step length |
Phi,
Theta |
absolute and turning angle, respectively |
T.start, T.end |
start and time of steps (numeric - in given units) |
T.mid |
temporal midpoint of the step |
dT |
duration of the step |
V |
approximate speed (S/dT) |
T.POSIX |
the temporal midpoint of the step as a POSIX objects. |
Eliezer Gurarie
data(Simp) plot(Simp) Simp.VT <- GetVT(Simp) head(Simp.VT) # Distribution of estimated speeds hist(Simp.VT$V, col="grey", breaks=20) # Distribution of turning angles require(circular) rose.diag(Simp.VT$Theta, bins=24)