Linear algrebra module
by Marc Lepage
OVERVIEW
The linear algebra module can perform common operations on three dimensional
vectors. It's useful when using LuaGL (OpenGL).
USAGE
-- import module
require "la"
-- create a few vectors (any table with numbers at indexes [1] [2] [3])
u, v = {1,0,0}, {0,1,0}
-- compute u + v
r = la.add(u, v) -- results are new vectors (convenience)
la.add(u, v, r) -- unless a result vector is specified (better performance)
la.add(u, v, u) -- which can safely be one of the operands (u += v)
-- compute u - v (so u is again {1,0,0})
la.sub(u, v, u)
-- dot product is projection (result is 0 since u and v are orthogonal)
la.dot(u, v)
-- cross product is right handed (result is {0,0,1})
la.cross(u, v)
-- negate and normalize (result is approx {-0.707,-0.707,0})
la.neg(la.norm({1,1,0}))
-- scalar multiplication (2*u) and division (v/3)
la.mul(u, 2)
la.div(v, 3)
RESOURCES
http://en.wikipedia.org/wiki/Linear_algebra
http://en.wikipedia.org/wiki/Euclidean_vector
http://en.wikipedia.org/wiki/Dot_product
http://en.wikipedia.org/wiki/Cross_product