coo_intersect_angle: Nearest intersection between a shape and a segment specified...

In vbonhomme/Momocs: Morphometrics using R

Nearest intersection between a shape and a segment specified with an angle

Description

Take a shape, and segment starting on the centroid and having a particular angle, which point is the nearest where the segment intersects with the shape?

Usage

coo_intersect_angle(coo, angle = 0)

coo_intersect_direction(coo, direction = c("down", "left", "up", "right")[4])

## Default S3 method:
coo_intersect_direction(coo, direction = c("down", "left", "up", "right")[4])

## S3 method for class 'Coo'
coo_intersect_direction(coo, direction = c("down", "left", "up", "right")[4])

Arguments

coo	matrix of ⁠(x; y)⁠ coordinates or any Coo object.
angle	numeric an angle in radians (0 by default).
direction	character one of "down", "left", "up", "right" ("right" by default)

Value

numeric the id of the nearest point or a list for Coo See examples.

Note

shapes are always centered before this operation. If you need a simple direction such as (down, left, up, right)ward, then use coo_intersect_direction which does not need to find an intersection but relies on coordinates and is about 1000.

See Also

Other coo_ intersect: coo_intersect_segment()

Examples

coo <- bot[1] %>% coo_center %>% coo_scale
coo_plot(coo)
coo %>% coo_intersect_angle(pi/7) %>%
   coo[., , drop=FALSE] %>% points(col="red")

 # many angles
 coo_plot(coo)
 sapply(seq(0, pi, pi/12),
       function(x) coo %>% coo_intersect_angle(x)) -> ids
 coo[ids, ] %>% points(col="blue")

 coo %>%
 coo_intersect_direction("down") %>%
 coo[.,, drop=FALSE] %>% points(col="orange")

vbonhomme/Momocs documentation built on Nov. 13, 2023, 8:54 p.m.