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Linearizes latitude-longitude GPS points to a provided route shape.

Source: R/avl_cleaning.R
get_linear_distances.Rd

This functions projects raw AVL data, as GPS latitude-longitude points, onto a provided route geometry, returning the distance of that point along the shape from the beginning terminal.

Usage

get_linear_distances(
  avl_df,
  shape_geometry,
  clip_buffer = NULL,
  original_crs = 4326,
  project_crs = 4326
)

Arguments

avl_df

A dataframe of raw AVL data. Must include at least longitude and latitude columns. See validate_tides().

shape_geometry

The SF object to project onto. Must be only one shape. See get_shape_geometry().

clip_buffer

Optional. The distance, in units of the used spatial projection, to clip the GPS points. Only points within this distance of the shape_geometry will be kept. Default is NULL, where no clip will be applied.

original_crs

Optional. A numeric EPSG identifier. If a dataframe is provided for points, this will be used to define the coordinate system of the longitude / latitude values. Default is 4326 (WGS 84 ellipsoid).

project_crs

Optional. A numeric EPSG identifer indicating the coordinate system to use for spatial calculations. Consider setting to a Euclidian projection, such as the appropriate UTM zone. Default is 4326 (WGS 84 ellipsoid).

Value

The input avl_df with latitude and longitude columns replaced by a distance column, in the units of the spatial projection used (e.g., meters if using UTM).

Examples

# Set my parameters
my_buffer <- 50 # meters
my_crs <- 32618

# Get input data
c53_avl <- new_transittraj_data("c53_avl")
c53_shape <- new_transittraj_data("get_shape_geometry")
dim(c53_avl)
#> [1] 709  12

# Run function
c53_dists <- get_linear_distances(avl_df = c53_avl,
                                  shape_geometry = c53_shape,
                                  clip_buffer = my_buffer,
                                  project_crs = my_crs)
dim(c53_dists)
#> [1] 639  11
head(c53_dists)
#>   location_ping_id vehicle_id trip_id_performed service_date route_id
#> 1             1586       5516          13437100   2026-02-16      C53
#> 2             1667       5516          13437100   2026-02-16      C53
#> 3             1694       5516          13437100   2026-02-16      C53
#> 4             1775       5516          13437100   2026-02-16      C53
#> 5             2018       5516          13437100   2026-02-16      C53
#> 6             2261       5516          13437100   2026-02-16      C53
#>   direction_id  speed trip_stop_sequence     event_timestamp stop_id distance
#> 1            0 6.4008                  2 2026-02-16 11:08:31   13111  0.00000
#> 2            0 0.0000                  2 2026-02-16 11:09:01   13111  2.08491
#> 3            0 0.0000                  2 2026-02-16 11:09:11   13111  2.08491
#> 4            0 0.0000                  2 2026-02-16 11:09:41   13111  2.08491
#> 5            0 0.0000                  2 2026-02-16 11:11:12   13111  2.08491
#> 6            0 0.0000                  2 2026-02-16 11:12:43   13111  2.08491