Magnitude

A magnitude is a quantity that represents a concrete measurement of some kind. In rigid geometric algebra, a magnitude $$\mathbf z$$ is composed of two components, a scalar and an antiscalar, as follows:

$$\mathbf z = x\mathbf 1 + y {\large\unicode{x1d7d9}}$$

Magnitudes are homogeneous just like everything else in a projective geometric algebra. This means it has both a bulk and a weight, and it is unitized by making the magnitude of its weight one.

Examples

• The geometric norm produces a magnitude that gives the perpendicular distance between an object and the origin. This is also half the distance that the origin is moved by an object used as an operator.
• Euclidean distances between objects are expressed as magnitudes given by the sum of the bulk norm and weight norm of expressions involving attitudes.
• Exponentiating the magnitude $$\delta\mathbf 1 + \phi {\large\unicode{x1d7d9}}$$ produces a motor for which $$\delta/\phi$$ is the pitch of the screw transformation.

See Also

• Geometric norm
• Unitization