distance_peers: Add distance to peers

In psyosphere: Analyse GPS Data

Description

Add distance in meters to peers within the same selection

Usage

distance_peers(
  tracks, cpeer = "", single = FALSE, average = TRUE, cname = "average_dis",
  bind = TRUE, drop = TRUE, t_id = "id"
)

Arguments

tracks	psyo. Data frame with tracks.
cpeer	character. Column that identifies peers.
single	logical. Append distances to each participant independently.
average	logical. Append average distances to peers.
cname	character. Column name for the average distance.
bind	logical. Return the distance as list (FALSE) or add it to tracks (TRUE).
drop	logical. If TRUE and only one observation is returned drop the data frame and collapse the return value to a vector.
t_id	character or numeric. Column name in tracks that identifies the peers that get compared with each other

Details

The function also determines the distance if the time stamps of the coordinates don't match. Please look at the example section for the details.

Only the distance to peers is determined. Therefore, distance to one-self is NA.

Value

psyo

Credit

If you use 'psyosphere' for commercial use or research, please support us by include one off the following references:

• MIT license: "psyosphere" by B. Ziepert, E. G. Ufkes & P. W. de Vries from https://CRAN.R-project.org/package=psyosphere

• APA: Ziepert, B., Ufkes, E., & de Vries, P. W. (2018). psyosphere: Analyse GPS Data. Retrieved from https://CRAN.R-project.org/package=psyosphere

• APA: Vries, P., Ziepert, B., & Ufkes, E. (2016). "De psychologie van bewegingen GPS-technologie voor de analyse van natuurlijk gedrag." Tijdschrift voor Human Factors 2: 11-15.

Note

Be aware: this function can take a lot time. You can use average_coordinates first to test your script with a small sample.

Author(s)

Benjamin Ziepert. Please send feedback to: [e-mail].

See Also

distance_line, distance_point, distance_psyo

Examples

## Not run: \dontrun{
# Simple example ---------------------------------------------------------------
data(psyo_rounds2)
time <- as.POSIXct("2015-09-03 13:51:07")
tracks <- psyo_rounds2[ psyo_rounds2[,"time"] == time, ]
tracks <- distance_peers(tracks)

# Example with intersect position ----------------------------------------------

#  p1 --------x-------> p2
#             ^
#             |
#             |
#            p3

# We have two tracks. From track 1 we have p1 and p2 at a certain time. From
# tracks 2 we have point 3. Point 3 has a time between p1 and p2. We want to
# know what the distance from point 3 is to track 1 at the time of point 3. For
# this we need determine point x.

# Create the points
p1 <- data.frame(time = "2016-01-01 01:00:00", lon = 0, lat = 0, id = "1")
p2 <- data.frame(time = "2016-01-01 03:00:00", lon = 2, lat = 0, id = "1")
p3 <- data.frame(time = "2016-01-01 02:00:00", lon = 1, lat = 1, id = "2")
p1$time <- as.POSIXct(p1$time)
p2$time <- as.POSIXct(p2$time)
p3$time <- as.POSIXct(p3$time)

# Combine into a track
tracks <- rbind(p1, p2, p3)

# Get point x for illustration
x <- psyosphere:::timed_destination_point_private(p1, p2, p3, "id")

# Plot points as track for illustration
plot <- plot_tracks(tracks)
plot

# Add x to plot for illustration
plot_tracks(x, plot = plot)

# Get distances
tracks <- distance_peers(tracks)
}
## End(Not run)

psyosphere documentation built on July 2, 2020, 12:08 a.m.