distSpeed {diveMove} | R Documentation |
Calculate distance, time difference, and velocity between pairs of points defined by latitude and longitude, given the time at which all points were measured.
distSpeed(pt1, pt2, velocity=TRUE) track(txy, id=gl(1, nrow(txy)), subset)
pt1 |
a matrix or data frame with three columns; the first a chron object with dates and times for all points, the second and third numeric vectors of longitude and latitude for all points, respectively, in decimal degrees. |
pt2 |
a matrix with the same structure as pt1 . |
velocity |
logical; should velocity between points be calculated? |
txy |
a data frame with a chron object in its first column, lon and lat in second and third column, respectively. |
id |
a factor dividing the data in txy into distinct
groups. |
subset |
a logical expression indicating the rows to be analyzed,
in terms of elements of txy . |
pt1
and pt2
may contain any number of rows.
track
is essentially a wrapper for distSpeed
, taking a
data frame, assumed to be ordered chronologically, and calculations
are done between all successive rows.
For distSpeed
, a matrix with three columns: distance (km),
time difference (h), and velocity (m/s). For track
, a data
frame with an id column and the same columns as in distSpeed
.
Sebastian P. Luque spluque@gmail.com