Selects spots near the segment defined by endpoints `A` and `B` using `build_one_trajectory()`, then orders the selected spots by their projection parameter (from `A` to `B`). The result is returned as a data frame.
Arguments
- df_rest
A data frame of candidate spots containing at least columns `x` and `y`.
- A
A data frame with columns `x` and `y` defining endpoint A of the segment. If it contains multiple rows, only the first row is used.
- B
A data frame with columns `x` and `y` defining endpoint B of the segment. If it contains multiple rows, only the first row is used.
- top_n
Integer; number of closest spots to keep (default `19`). If `NULL`, no top-N truncation is applied.
- max_dist
Numeric; if not `NULL`, only spots with distance to the segment `<= max_dist` are kept.
Value
A data frame of selected spots (subset of `df_rest`) ordered along the segment (in increasing `pos_on_seg`). The output includes the extra columns added by `build_one_trajectory()` (typically `dist_to_seg` and `pos_on_seg`).
Details
This function is a thin wrapper around `build_one_trajectory()` that returns only the ordered `selected` data frame (and not the segment metadata).
It uses the base R pipe `|>` and `dplyr::arrange()`.
Examples
df <- data.frame(
x = c(0, 1, 2, 3, 4, 2),
y = c(0, 0, 0, 0, 0, 1),
id = 1:6
)
A <- data.frame(x = 0, y = 0)
B <- data.frame(x = 4, y = 0)
build_one_line(df, A, B, top_n = 5)
#> x y id dist_to_seg pos_on_seg trajectory_id
#> 1 0 0 1 0 0.00 main
#> 2 1 0 2 0 0.25 main
#> 3 2 0 3 0 0.50 main
#> 4 3 0 4 0 0.75 main
#> 5 4 0 5 0 1.00 main