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Get point closest to a given direction

Source: R/get.R
get_closest_direction.Rd

Find the index of the point closest to a specified direction from the centroid.

Usage

get_closest_direction(x, ..., .cols = NULL)

Arguments

x

A matrix (nx2), list of matrices, or tibble with coo columns.

...

Additional arguments (reserved for future use).

.cols

Column name(s) to process when x is a tibble. If NULL, automatically detects columns containing coo objects.

direction

Character. One of "right", "up", "left", or "down".

Value

  • If x is a single matrix: returns an integer (point index)

  • If x is a list: returns an integer vector

  • If x is a tibble: returns an integer vector extracted from coo column

Details

Centers the shape, calculates the angle from centroid to each point, and returns the index of the point whose angle is closest to the specified direction:

  • "right" = 0 radians (East)

  • "up" = pi/2 radians (North)

  • "left" = pi radians (West)

  • "down" = -pi/2 radians (South)

See also

get_closest(), get_closest_angle()

Examples

# Find point closest to East
get_closest_direction(shapes$cat, direction = "right")
#> [1] 105

# Find point closest to North
get_closest_direction(shapes$cat, direction = "up")
#> [1] 70