Vector operations

Usage

vlength(x)

vsum(x, w = NULL)

vnorm(x)

vscale(x, l)

vcross(x, y)

vdot(x, y)

vrotate(x, rotaxis, rotangle)

vangle(x, y)

vproject(x, y)

vreject(x, y)

Arguments

x, y, rotaxis: numeric vector, array, or object of class "line" or "plane"
w: weights.
l: numeric. length to scale x
rotangle: numeric. Angle in radians or degrees if "rotaxis" is an object of "line" or "plane"

Details

vlength(x) returns the length of a vector x.

vsum(x) returns the vector sum of x. If w is specified.

vscale(x) returns a vector x with length l.

vnorm(x) returns the normalized vector x (i.e. vlength(x) = 1)

vcross(x, y) returns the cross product of vectors x and y which is a new vector perpendicular to both.

vdot(x, y) returns the dot product (or scalar product) of x and y. vdot(x, y) is equivalent to x %*% t(y)

vrotate(x, rotaxis, rotangle) rotates x about a vector by a specified angle.

vproject(x,y) projects x on vector y, i.e. returns a vector that has same orientation as y but length of x.

vreject(x,y) Is the vector between x and the projected vector of x onto y (also called the vector resolute of x perpendicular to y)

Examples

vec1 <- cbind(1, 0, 0)
vec2 <- cbind(0, 0, 1)

vlength(vec1)
#> [1] 1
vsum(vec1)
#>      [,1] [,2] [,3]
#> [1,]    1    0    0
vnorm(vec1)
#>      [,1] [,2] [,3]
#> [1,]    1    0    0
vcross(vec1, vec2)
#>      x  y z
#> [1,] 0 -1 0
vdot(vec1, vec2)
#> [1] 0
vrotate(vec1, vec2, pi / 2)
#>                 x y z
#> [1,] 2.220446e-16 1 0
vangle(vec1, vec2)
#> [1] 1.570796
vproject(vec1, vec2)
#>      x y z
#> [1,] 0 0 0
vreject(vec1, vec2)
#>      x y z
#> [1,] 1 0 0