filter_positions_at_range: Retain only positions within a range from a location.

In euctrl-pru/trrrj: Flight trajectories analysis

Retain only positions within a range from a location.

Description

The points whose distance, .distance, satisfies

dm <= .distance < dM

are kept (.exclude = FALSE) or excluded (.exclude = TRUE)

Usage

filter_positions_at_range(
  df,
  geo,
  dm,
  dM,
  lon,
  lat,
  .exclude = FALSE,
  .keep = FALSE
)

Arguments

df	a (trajectory) data frame
geo	a geographical location in lon/lat (WGS84)
dm	a distance in Nautical Miles
dM	a distance in Nautical Miles
lon	the column for longitude in df
lat	the column for latitude in df
.exclude	exclude the point in the (dm, dM) [default is FALSE]
.keep	keep the calculated distance (in Nautical Miles) in the .distance column [default is FALSE]

Value

a subset of df

See Also

Other spatial: bbox_at_distance(), bounding_box(), crs_tc(), polygon_at_distance(), polygon_from_coords()

Examples

## Not run: 
fra <- c(8.570556, 50.03333) # Frankfurt Airport (longitude, latitude)

# keep the points 40 NM from FRA
poss %>% filter_positions_at_range(fra, 0, 40, longitude, latitude)
# keep the points from 10 to 40 NM from FRA
poss %>% filter_positions_at_range(fra, 10, 40, longitude, latitude)
# exclude the points from 10 to 40 NM from FRA
poss %>% filter_positions_at_range(fra, 10, 40, longitude, latitude, .exclude = TRUE)
# keep the points further away of 40 NM from FRA
poss %>% filter_positions_at_range(fra, 0, 40, longitude, latitude, .exclude = TRUE)

## End(Not run)

euctrl-pru/trrrj documentation built on April 15, 2024, 1:24 p.m.