R: Compute external- or 'cross'- product of 3D vectors.

extprod3d {geometry} | R Documentation

## Compute external- or ‘cross’- product of 3D vectors.

### Description

Computes the external product

(x2 * y3 - x3 * y2, x3 * y1 - x1 * y3, x1 * y2 - x2 * y1)

(x2 * y3 - x3 * y2, x3 * y1 - x1 * y3, x1 * y2 - x2 * y1)

(x2 * y3 - x3 * y2, x3 * y1 - x1 * y3, x1 * y2 - x2 * y1)

of the 3D vectors in x and y.

### Usage

    extprod3d(x, y, drop = TRUE)

### Arguments

`x` | `n`-by-3 matrix. Each row is one x-vector
`y` | `n`-by-3 matrix. Each row is one y-vector
`drop` | logical. If `TRUE` and if the inputs are one row matrices or vectors, then delete the dimensions of the array returned.

### Value

If `n` is greater than 1 or `drop` is `FALSE`, `n`-by-3 matrix; if `n` is 1 and `drop` is `TRUE`, a vector of length 3.

### Author(s)

Raoul Grasman

### See Also

drop

[Package geometry version 0.4.0 Index]